Advanced Navigation Motus Reference Manual
Text of the manual
Motus Reference Manual
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Table of Contents
1 Revision History..........................................................................................................8
2 Firmware Changelog...................................................................................................9
3 Hardware Changelog................................................................................................10
4 Introduction..............................................................................................................11
5 Foundation Knowledge.............................................................................................12
5.1 GNSS.................................................................................................................12
5.2 INS.....................................................................................................................12
5.3 GNSS/INS...........................................................................................................12
5.4 AHRS.................................................................................................................12
5.5 The Sensor Co-ordinate Frame..........................................................................12
5.6 Roll, Pitch and Heading......................................................................................13
5.6.1 Second Right Hand Rule.............................................................................13
5.6.2 Rotation Order............................................................................................14
5.7 Geodetic Co-ordinate System............................................................................14
5.8 NED Co-ordinate Frame.....................................................................................16
5.9 ECEF Co-ordinate Frame....................................................................................17
6 Rugged Evaluation Kit..............................................................................................18
6.1 Kit Contents.......................................................................................................18
6.2 Quick Start.........................................................................................................18
7 OEM Evaluation Kit...................................................................................................19
7.1 Kit Contents.......................................................................................................19
7.2 Quick Start.........................................................................................................19
8 Part Numbers and Ordering Options.........................................................................20
8.1 Evaluation Kit....................................................................................................20
8.2 Standalone Unit.................................................................................................20
8.3 Software License Upgrades...............................................................................20
8.4 Accessories........................................................................................................21
9 Specifications...........................................................................................................22
9.1 Mechanical Drawings.........................................................................................22
9.2 Navigation Specifications..................................................................................23
9.3 Sensor Specifications.........................................................................................24
9.4 Rugged Communication Specifications..............................................................24
9.5 OEM Communication Specifications..................................................................25
9.6 Rugged Hardware Specifications.......................................................................25
9.7 OEM Hardware Specifications............................................................................26
9.8 Rugged Electrical Specifications........................................................................26
9.9 OEM Electrical Specifications.............................................................................27
9.10 Power Consumption.........................................................................................28
9.11 Rugged Connector Pin-out...............................................................................28
9.12 Rugged Evaluation Kit USB Cable....................................................................29
9.13 Optional Rugged Breakout Cable.....................................................................30
9.14 Sensor Calibration...........................................................................................31
9.15 Serial Number..................................................................................................31
10 Installation..............................................................................................................33
10.1 Installation Checklist.......................................................................................33
10.2 Position and Alignment....................................................................................33
10.2.1 Alignment.................................................................................................33
10.3 Mounting Plate.................................................................................................33
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10.4 Power Supply...................................................................................................34
10.5 Odometer........................................................................................................35
10.5.1 Factory VSS Signal....................................................................................35
10.5.2 OBDII Odometer Interface........................................................................35
10.5.3 Aftermarket Wheel Speed Sensor.............................................................36
10.5.4 Radar Speed Sensor.................................................................................36
10.6 Magnetics........................................................................................................37
10.7 Vibration..........................................................................................................37
11 INS and AHRS Operation.........................................................................................38
11.1 Initialisation.....................................................................................................38
11.1.1 Orientation Initialisation...........................................................................38
11.1.2 Navigation Initialisation............................................................................38
11.1.3 Heading Initialisation................................................................................39
11.1.4 Time Initialisation.....................................................................................39
11.2 Hot Start..........................................................................................................39
11.3 Time................................................................................................................39
11.4 Heading Source...............................................................................................40
11.4.1 Magnetic Heading.....................................................................................40
11.4.2 Velocity Heading.......................................................................................40
11.4.3 External Heading......................................................................................40
11.5 Magnetics........................................................................................................40
11.5.1 2D Magnetic Calibration...........................................................................41
11.5.1.1 Using the Motus Manager Software...................................................41
11.5.1.2 Using the Packet Protocol..................................................................41
11.5.2 3D Magnetic Calibration...........................................................................42
11.5.2.1 Using the Motus Manager Software...................................................42
11.5.2.2 Using the Packet Protocol..................................................................42
11.5.3 Automatic Magnetic Calibration...............................................................42
11.5.4 Disabling Magnetometers.........................................................................43
11.6 Data Anti Aliasing............................................................................................43
11.7 Vehicle Profiles................................................................................................43
11.8 Odometer Pulse Length...................................................................................43
11.8.1 Odometer Automatic Pulse Length Calibration Procedure........................43
11.9 Reversing Detection........................................................................................44
11.10 Motion Analysis..............................................................................................44
11.11 Heave............................................................................................................44
11.12 Environmental Exposure................................................................................44
11.12.1 Temperature...........................................................................................45
11.12.2 Water......................................................................................................45
11.12.3 Salt.........................................................................................................45
11.12.4 Dirt and Dust..........................................................................................45
11.12.5 PH Level..................................................................................................45
11.12.6 Shocks....................................................................................................45
12 Motus Manager.......................................................................................................46
12.1 Software Changelog........................................................................................47
12.2 System Requirements......................................................................................47
12.3 Installation.......................................................................................................47
12.4 Troubleshooting...............................................................................................47
12.4.1 All Platforms.............................................................................................47
12.4.2 Windows...................................................................................................47
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12.4.3 Linux.........................................................................................................48
12.5 Main View........................................................................................................50
12.5.1 Serial Port.................................................................................................50
12.5.2 Attitude Indicator......................................................................................50
12.5.3 Status Indicator........................................................................................50
12.5.3.1 Motus Status Indicator.......................................................................51
12.5.3.2 Fix Indicator.......................................................................................51
12.5.3.3 Satellites Table..................................................................................51
12.5.4 3D Map.....................................................................................................51
12.5.5 3D Map Controls.......................................................................................51
12.5.5.1 Reset View.........................................................................................51
12.5.5.2 Clear History......................................................................................51
12.6 Logging............................................................................................................51
12.7 View.................................................................................................................52
12.7.1 Device Information...................................................................................53
12.7.2 Status.......................................................................................................53
12.7.3 Satellites...................................................................................................54
12.7.4 Raw Sensors.............................................................................................55
12.7.5 Orientation...............................................................................................56
12.7.6 Position.....................................................................................................57
12.7.7 Velocity and Acceleration.........................................................................58
12.7.8 3D Model..................................................................................................59
12.7.9 Communications Statistics.......................................................................60
12.7.10 Heave.....................................................................................................60
12.8 Configuration...................................................................................................61
12.8.1 Configuration Export................................................................................61
12.8.2 Filter Options............................................................................................62
12.8.3 Packet Rates.............................................................................................63
12.8.4 Alignment Configuration...........................................................................64
12.8.4.1 Alignment Offset................................................................................64
12.8.4.2 GNSS Antenna Offset.........................................................................64
12.8.4.3 Odometer Offset................................................................................65
12.8.4.4 External Data Offset..........................................................................65
12.8.5 Baud Rates...............................................................................................65
12.8.6 GPIO Configuration...................................................................................66
12.8.7 Odometer.................................................................................................66
12.8.8 Reset........................................................................................................67
12.8.9 Reference Position Offsets........................................................................67
12.8.10 GPIO Output...........................................................................................68
12.8.11 Manual Initialisation................................................................................69
12.9 Tools................................................................................................................69
12.9.1 Magnetic Calibration.................................................................................70
12.9.2 Firmware Update......................................................................................71
12.9.3 Log Converter...........................................................................................71
12.9.4 Network Connect......................................................................................72
13 OEM Integration......................................................................................................73
13.1 OEM PCB Mechanical Mounting.......................................................................73
13.2 OEM Electrical Connector................................................................................74
13.2.1 Interoperability with Different Voltage Systems.......................................76
13.2.2 Reset Line.................................................................................................76
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13.2.3 Basic Connection......................................................................................77
13.3 Recommended Footprint.................................................................................77
13.4 OEM Power Supply...........................................................................................79
13.5 OEM Pin Protection..........................................................................................79
14 OEM Development Board........................................................................................80
14.1 Serial UART to USB Converter..........................................................................81
14.2 Dual RS232 Transceiver...................................................................................81
14.3 GPIO Header and Status LEDs.........................................................................81
14.4 Configuration Switches....................................................................................82
14.4.1 Primary Serial Port to USB........................................................................83
14.4.2 Primary Serial Port to RS232 1 and GPIO 3 & 4 to RS232 2......................84
14.4.3 Primary Serial Port and GPIO 3 & 4 to GPIO Header at TTL levels.............84
14.5 Power source...................................................................................................85
14.6 Schematics......................................................................................................85
15 Interfacing..............................................................................................................88
15.1 Communication...............................................................................................88
15.1.1 Baud Rate.................................................................................................88
15.2 External Data...................................................................................................88
15.3 GPIO Pins and Auxiliary RS232........................................................................89
15.4 Dynamic Pin Functions.....................................................................................89
15.4.1 1PPS Output.............................................................................................90
15.4.2 GNSS Fix Output.......................................................................................91
15.4.3 Odometer Input........................................................................................91
15.4.4 Zero Velocity Input...................................................................................91
15.4.5 Pitot Tube Input.........................................................................................91
15.4.6 NMEA Input...............................................................................................91
15.4.7 NMEA Output............................................................................................92
15.4.8 Novatel GNSS Input..................................................................................92
15.4.9 Topcon GNSS Input...................................................................................93
15.4.10 ANPP Input..............................................................................................93
15.4.11 ANPP Output...........................................................................................93
15.4.12 Disable Magnetometers..........................................................................93
15.4.13 Set Zero Orientation Alignment..............................................................93
15.4.14 System State Packet Trigger...................................................................93
15.4.15 Raw Sensors Packet Trigger....................................................................93
15.4.16 Pressure Depth Transducer.....................................................................93
15.4.17 Trimble GNSS Input.................................................................................93
15.4.18 u-blox GNSS Input...................................................................................94
15.4.19 Hemisphere GNSS Input.........................................................................94
15.4.20 Teledyne DVL Input.................................................................................94
15.4.21 Tritech USBL Input..................................................................................94
15.4.22 Linkquest DVL Input...............................................................................94
15.4.23 Linkquest USBL Input..............................................................................94
15.4.24 Nortek DVL Input....................................................................................94
15.4.25 Left Wheel Speed Sensor........................................................................94
15.4.26 Right Wheel Speed Sensor.....................................................................94
15.4.27 1PPS Input..............................................................................................94
15.4.28 Wheel Speed Sensor...............................................................................95
15.4.29 Wheel Encoder Phase A..........................................................................95
15.4.30 Wheel Encoder Phase B..........................................................................95
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15.4.31 Event 1 Input..........................................................................................95
15.4.32 Event 2 Input..........................................................................................95
15.4.33 TSS1 Output...........................................................................................95
15.4.34 Simrad 1000 Output...............................................................................95
15.4.35 Simrad 3000 Output...............................................................................96
15.4.36 Serial Port Passthrough...........................................................................96
15.4.37 Gimbal Encoder Phase A.........................................................................96
15.4.38 Gimbal Encoder Phase B.........................................................................96
15.4.39 Odometer Direction, Forward Low..........................................................96
15.4.40 Odometer Direction, Forward High.........................................................96
15.4.41 Reverse Alignment, Forward Low............................................................96
15.4.42 Reverse Alignment, Forward High..........................................................96
15.4.43 Zero Angular Velocity Input....................................................................96
16 Advanced Navigation Packet Protocol.....................................................................97
16.1 Data Types.......................................................................................................97
16.2 Packet Structure..............................................................................................97
16.2.1 Header LRC...............................................................................................98
16.2.2 Packet ID..................................................................................................98
16.2.3 Packet Length...........................................................................................98
16.2.4 CRC...........................................................................................................98
16.3 Packet Requests..............................................................................................98
16.4 Packet Acknowledgement................................................................................98
16.5 Packet Rates....................................................................................................99
16.6 Packet Timing..................................................................................................99
16.7 Packet Summary..............................................................................................99
16.8 System Packets..............................................................................................101
16.8.1 Acknowledge Packet...............................................................................101
16.8.1.1 Acknowledge Result........................................................................102
16.8.2 Request Packet.......................................................................................102
16.8.3 Boot Mode Packet...................................................................................103
16.8.3.1 Boot Mode Types.............................................................................103
16.8.4 Device Information Packet......................................................................103
16.8.5 Restore Factory Settings Packet..............................................................104
16.8.6 Reset Packet...........................................................................................104
16.8.6.1 Verification Sequence Values...........................................................104
16.8.7 Serial Port Pass-through Packet..............................................................104
16.8.7.1 Pass-through Routes........................................................................104
16.9 State Packets.................................................................................................106
16.9.1 System State Packet...............................................................................106
16.9.1.1 System Status.................................................................................107
16.9.1.2 Filter Status.....................................................................................108
16.9.1.3 GNSS Fix Status...............................................................................108
16.9.1.4 Unix Time Seconds..........................................................................109
16.9.1.5 Microseconds...................................................................................109
16.9.2 Unix Time Packet....................................................................................109
16.9.3 Formatted Time Packet...........................................................................109
16.9.4 Status Packet..........................................................................................109
16.9.5 Position Standard Deviation Packet........................................................110
16.9.6 Velocity Standard Deviation Packet........................................................110
16.9.7 Euler Orientation Standard Deviation Packet..........................................110
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16.9.8 Quaternion Orientation Standard Deviation Packet................................111
16.9.9 Raw Sensors Packet................................................................................111
16.9.10 Raw GNSS Packet.................................................................................112
16.9.10.1 Raw GNSS Status...........................................................................112
16.9.11 Satellites Packet...................................................................................113
16.9.12 Detailed Satellites Packet.....................................................................113
16.9.12.1 Satellite Systems...........................................................................114
16.9.12.2 Satellite Frequencies.....................................................................114
16.9.13 Geodetic Position Packet.......................................................................115
16.9.14 ECEF Position Packet.............................................................................115
16.9.15 UTM Position Packet..............................................................................115
16.9.16 NED Velocity Packet..............................................................................116
16.9.17 Body Velocity Packet.............................................................................116
16.9.18 Acceleration Packet..............................................................................116
16.9.19 Body Acceleration Packet.....................................................................117
16.9.20 Euler Orientation Packet.......................................................................117
16.9.21 Quaternion Orientation Packet.............................................................117
16.9.22 DCM Orientation Packet........................................................................118
16.9.23 Angular Velocity Packet........................................................................118
16.9.24 Angular Acceleration Packet.................................................................119
16.9.25 External Position & Velocity Packet.......................................................119
16.9.26 External Position Packet........................................................................119
16.9.27 External Velocity Packet.......................................................................120
16.9.28 External Body Velocity Packet...............................................................120
16.9.29 External Heading Packet.......................................................................121
16.9.30 Running Time Packet............................................................................121
16.9.31 Local Magnetic Field Packet..................................................................121
16.9.32 Odometer State Packet.........................................................................122
16.9.33 External Time Packet............................................................................122
16.9.34 External Depth Packet..........................................................................122
16.9.35 Geoid Height Packet.............................................................................123
16.9.36 External Pitot Pressure Packet..............................................................123
16.9.37 Wind Packet..........................................................................................123
16.9.38 Heave Packet........................................................................................124
16.9.39 Post Processing Packet.........................................................................124
16.9.40 External Odometer Packet....................................................................124
16.9.40.1 Odometer flags..............................................................................124
16.9.41 External Air Data Packet.......................................................................125
16.9.41.1 External Air Data Flags..................................................................125
16.9.41.2 Notes.............................................................................................125
16.9.42 Gimbal State Packet.............................................................................125
16.9.43 Automotive Packet................................................................................126
16.9.44 Zero Angular Velocity Packet................................................................126
16.9.44.1 Duration........................................................................................126
16.10 Configuration Packets..................................................................................127
16.10.1 Packet Timer Period Packet...................................................................127
16.10.1.1 UTC Synchronisation......................................................................127
16.10.1.2 Packet Timer Period.......................................................................127
16.10.2 Packets Period Packet...........................................................................127
16.10.2.1 Clear Existing Packets...................................................................128
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16.10.2.2 Packet Period.................................................................................128
16.10.3 Baud Rates Packet................................................................................128
16.10.4 Installation Alignment Packet...............................................................129
16.10.4.1 Alignment DCM..............................................................................129
16.10.5 Filter Options Packet.............................................................................130
16.10.5.1 Vehicle Types.................................................................................131
16.10.6 Advanced Filter Parameters Packet.......................................................131
16.10.7 GPIO Configuration Packet....................................................................131
16.10.7.1 GPIO1 Functions............................................................................132
16.10.7.2 GPIO2 Functions............................................................................133
16.10.7.3 Auxiliary RS232 Transmit Functions...............................................134
16.10.7.4 Auxiliary RS232 Receive Functions................................................135
16.10.8 Magnetic Calibration Values Packet......................................................136
16.10.9 Magnetic Calibration Configuration Packet...........................................136
16.10.9.1 Magnetic Calibration Actions.........................................................136
16.10.10 Magnetic Calibration Status Packet....................................................137
16.10.10.1 Magnetic Calibration Status.........................................................137
16.10.11 Odometer Configuration Packet..........................................................138
16.10.12 Set Zero Orientation Alignment Packet...............................................138
16.10.13 Reference Point Offsets Packet...........................................................138
16.10.14 GPIO Output Configuration Packet......................................................140
16.10.14.1 NMEA Fix Behaviour.....................................................................140
16.10.14.2 GPIO Output Rates.......................................................................141
16.10.14.3 GPIO Output Rates Index.............................................................141
16.10.15 User Data Packet................................................................................141
16.10.16 GPIO Input Configuration Packet.........................................................142
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1
Revision History
Version
Date
Changes
1.1
29/11/2019
Updated firmware changelog 2
Updated hardware changelog 3
Updated dynamic pin functions table 15.4
Updated GPIO configuration packet 16.10.7
Added pressure depth transducer deprecated input
function 15.4.16
Added Nortek DVL input function 15.4.24
Added Teledyne DVL input function 15.4.20
Added Tritech USBL input function 15.4.21
Added Linkquest DVL input function 15.4.22
Added Linkquest USBL input functionality 15.4.23
Added reverse alignment input functions 15.4.41
Added zero angular velocity input function 15.4.43
Clarified port baud rates in sections 9.4, 15.1, 15.3 and
16.10.3
Updated read status for external air data packet 16.7
Updated read status for external odometer packet 16.9.40
Modified quaternion element labels 16.9.8 and 16.9.21
Clarified geoid height packet description 16.9.35
Removed external pitot pressure packet 16.9.36
Updated external body velocity packet size and definition
16.9.28
Added wheel speed sensor specifications 15.4.28
Corrected Raw GNSS packet velocity units 16.9.10
Updated GPIO output configuration packet 16.10.14
Clarified negative acknowledgement packets 16.8.1
Clarified 1PPS output voltages 15.4.1
Updated specifications 9
Clarified navigation specifications 9.2
Corrected power supply drop out voltage 10.4
Added odometer information to Installation chapter 10.5
Added magnetics information to Installation chapter 10.6
Updated operating temperature information 11.12.1
Corrected IP rating of rugged enclosure 9.6 and 11.12.2
Clarified raw GNSS data output packets 16.9.10, 16.9.11,
16.9.12
Corrected system status and filter status flags 16.9.1.1,
16.9.1.2
Corrected raw sensors packet fields 16.9.9
1.0
17/03/2016
Initial Release
Table 1: Revision history
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2
Firmware Changelog
Version
Date
Changes
1.6
28/11/2019
Improvements to raw sensor calibration algorithm
Prevents fast temperature variations from introducing
digital noise into accelerometer values which was
regression from firmware version 1.4
1.5
03/10/2019
Improvements to raw sensor calibration algorithm
More accurate temperature compensation of sensors leads
to overall performance improvement
Improvements to heading integrity monitoring algorithm to
better reject erroneous measurements
1.4
05/09/2019
Improvements to raw sensor calibration algorithm
Better sensor performance through rapid temperature
changes leads to performance improvement in cases of
fast temperature ramps
1.3
31/05/2019
Improvements to integrity monitoring allows better
rejection of erroneous position and velocity data
1.1
17/07/2018
New zero angular velocity functionality
Better hot start performance
1.0
01/03/2016
Initial release
Table 2: Firmware changelog
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3
Hardware Changelog
Version
Date
Changes
1.4
16/07/2018
Internal manufacturing improvements
No noticeable changes for customers
1.3
07/09/2017
Improvements to ADC synchronisation results in slightly
improved performance under high dynamics
1.2
05/10/2016
Internal manufacturing improvements
1.0
14/09/2015
Initial release
Table 3: Hardware changelog
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4
Introduction
Motus is a miniature ultra high accuracy MEMS IMU. It features some of the highest
accuracy MEMS accelerometers and gyroscopes currently available combined with
magnetometers. Motus is fully calibrated for all sensor errors over a wide temperature
range and can be software upgraded to AHRS or INS functionality. It is available in both
OEM and enclosed (rugged) packages.
Motus can provide amazing results but it does need to be set up properly and
operated with an awareness of its limitations. Please read through this manual
carefully to ensure success within your application.
The Motus Manager software is downloadable from the software tab of the Motus page
on the Advanced Navigation website. It allows Motus to be easily configured and
tested. It is referenced throughout this manual.
If you have any questions please contact [email protected].
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5
Foundation Knowledge
This chapter is a learning reference that briefly covers knowledge essential to
understanding Motus and the following chapters. It explains the concepts in simple
terms so that people unfamiliar with the technology may understand it.
5.1
GNSS
GNSS stands for global navigation satellite system. A GNSS consists of a number of
satellites in space that broadcast navigation signals. These navigation signals can be
picked up by a GNSS receiver on the earth to determine that receiver’s position and
velocity. For a long time the only operational GNSS was the United States GPS.
However the Russian GLONASS is now fully operational with similar performance to
GPS. The Chinese BeiDou is in the process of becoming operational and the European
Union’s GALILEO should be operational within five years.
GNSS is excellent for navigational purposes and provides fairly accurate position (2.5
metres) and velocity (0.05 metres/second). The main drawback of GNSS is that the
receiver must have a clear signal from at least 4 satellites to function. GNSS satellite
signals are very weak and struggle to penetrate through buildings and other objects
obstructing view of the sky. GNSS can also occasionally drop out due to disturbances in
the upper atmosphere.
5.2
INS
INS stands for inertial navigation system. An inertial navigation system can provide
position and velocity similar to GNSS but with some big differences. The principle of
inertial navigation is the measurement of acceleration. This acceleration is then
integrated into velocity. The velocity is then integrated into position. Due to noise in
the measurement and the compounding of that noise through the integration, inertial
navigation has an error that increases exponentially over time. Inertial navigation
systems have a very low relative error over short time periods but over long time
periods the error can increase dramatically.
5.3
GNSS/INS
By combining GNSS and INS together in a mathematical algorithm, it is possible to
take advantage of the benefits of GNSS long-term accuracy and INS short-term
accuracy. This provides an overall enhanced position and velocity solution that can
withstand short GNSS drop outs.
5.4
AHRS
AHRS stands for attitude and heading reference system. An AHRS uses
accelerometers, gyroscopes and magnetometers combined in a mathematical
algorithm to provide orientation. Orientation consists of the three body angles roll,
pitch and heading.
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5.5
The Sensor Co-ordinate Frame
Inertial sensors have 3 different axes: X, Y and Z and these determine the directions
around which angles and accelerations are measured. It is very important to align the
axes correctly in installation otherwise the system won't work correctly. These axes are
marked on the top of the device as shown in Illustration 1 below with the X axis
pointing in the direction of the connector, the Z axis pointing down through the base of
the unit and the Y axis pointing out of the starboard side.
When installed in an application the X axis should be aligned such that it points
forwards and the Z axis aligned so that it points down when level. A good way to
remember the sensor axes is the right hand rule, which is visualised in Illustration 2.
You take your right hand and extend your thumb, index and middle. Your thumb then
denotes the X axis, your index denotes the Y axis and your middle denotes the Z axis.
5.6
Roll, Pitch and Heading
Orientation can be described by the three angles roll, pitch and heading, these are
known as the Euler angles. The rotation axes of roll, pitch and heading are shown
visually in Illustration 1. The arrow indicates the positive rotation direction.
Roll is the angle around the X axis and is zero when the unit is level. Pitch is the angle
around the Y axis and is zero when the unit is level. Heading is the angle around the Z
axis and is zero when the positive X axis is pointing to true north.
5.6.1
Second Right Hand Rule
The two right hand rules are often the best way to memorise the sensor axes and
directions of positive rotation. The first right hand rule gives the positive axis
directions and is described in section 5.5. The second right hand rule shown in
Illustration 3 provides the direction of positive rotation. To use it, point your thumb in
the positive direction of that axis, then the direction that your fingers curl over is the
Illustration 2: First right hand rule
Illustration 1: Motus axes
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positive rotation on that axis.
5.6.2
Rotation Order
When multiple axes are rotated, to imagine the final orientation the three rotations
must be performed in the order heading first, then pitch and then roll. To deduce the
final orientation the unit should first be considered level with the X axis pointing north
and the Z axis pointing down. Heading is applied first, then pitch is applied and finally
roll is applied to give the final orientation. This can be hard for some people to grasp
at first and is often best learned experimentally by rotating Motus with your hand
whilst watching the orientation plot in real time on the computer.
5.7
Geodetic Co-ordinate System
The geodetic co-ordinate system is the most popular way of describing an absolute
position on the Earth. It is made up of the angles latitude and longitude combined with
a height relative to the ellipsoid. Latitude is the angle that specifies the north to south
position of a point on the Earth's surface. Longitude is the angle that specifies the east
to west position of a point on the Earth's surface. The line of zero latitude is the
equator and the line of zero longitude is the prime meridian. Illustration 4 shows how
latitude and longitude angles are used to describe a position on the surface of the
Earth.
Illustration 3: Second right hand rule
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Illustration 5 shows latitude and longitude on a map of the world.
Illustration 4: Latitude and longitude represented visually to describe a position
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Latitude and longitude give the 2D point on the surface of the Earth. These are
combined with height to give the 3D position on the Earth.
Height is the height above the WGS84 reference ellipsoid. The WGS84 reference
ellipsoid is a model used to approximate sea level across the Earth. Therefore the
height should be considered approximately relative to sea level. Due to the
approximate nature of the WGS84 model, the WGS84 height will not be the same as
the actual sea level. For example, in Australia, the WGS84 height at sea level is 9
metres at some points.
5.8
NED Co-ordinate Frame
The NED (North East Down) co-ordinate frame is used to express velocities and
relative positions. The origin of the co-ordinate frame can be considered the current
position. From that origin, the north axis points true north and parallel to the line of
longitude at that point. The east axis points perpendicular to the north axis and
parallel to the line of latitude at that point. The down axis points directly down towards
the centre of the Earth. See Illustration 6 for a graphical representation of the NED co-
ordinate frame at a position on the Earth.
Illustration 5: World map showing latitudes and longitudes
Equator
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5.9
ECEF Co-ordinate Frame
The ECEF (Earth-centred earth-fixed) co-ordinate frame is a Cartesian co-ordinate
frame used to represent absolute positions on the Earth. It's origin is at the centre of
the Earth. ECEF is an alternative to the geodetic co-ordinate frame. It is represented
by the three axes X, Y and Z which are presented graphically in Illustration 6. ECEF
positions can be retrieved from Advanced Navigation products however the geodetic
system is used as the default.
Illustration 6: Graphic showing geodetic, NED and ECEF co-ordinates
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6
Rugged Evaluation Kit
Motus is supplied in an evaluation kit that contains everything required to get started
operating the system right away. The evaluation kit is supplied in a plastic carry case
to protect the equipment during shipping.
6.1
Kit Contents
1. Motus Rugged unit
2. 2 metre USB to RS232 cable, part number A503-SDC20796, see section 9.12
6.2
Quick Start
1. Plug the interface cable into Motus.
2. Plug the USB end of the interface cable into your computer.
3. Download the Motus Manager software from the Motus page of the Advanced
Navigation website. Java is required to run the software. Java is available from
http://www.java.com if not already installed.
4. Click the connect button in Motus Manager.
5. The various windows in Motus Manager can be used to view the real time data.
6. To view the data logs, click disconnect in Motus Manager. In the Tools menu,
select Log Converter and press Convert. The *.anpp binary log file will be
converted to CSV files that can be opened with popular data processing
programs such as Matlab or Microsoft Excel. The log files can be found in the
same folder as the Motus Manager software.
Illustration 7: Motus Evaluation Kit case
Illustration 8: Motus Evaluation Kit contents
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7
OEM Evaluation Kit
Motus OEM is supplied in an evaluation kit that contains everything required to get
started operating the system right away. The evaluation kit is supplied in a plastic
carry case to protect the equipment during shipping.
7.1
Kit Contents
1. Motus OEM unit
2. Motus OEM development board
3. Mini USB cable
7.2
Quick Start
1. Mount the Motus OEM unit onto the Motus OEM development board and screw it
down.
2. Plug one end of the USB cable into the Motus development board and the other
end into your computer.
3. Download the Motus Manager software from the Motus page of the Advanced
Navigation website. Java is required to run the software. Java is available from
http://www.java.com if not already installed.
4. Click the connect button in Motus Manager.
5. The various windows in Motus Manager can be used to view the real time data.
6. To view the data logs, click disconnect in Motus Manager. In the Tools menu,
select Log Converter and press Convert. The *.anpp binary log file will be
converted to CSV files that can be opened with popular data processing
programs such as Matlab or Microsoft Excel. The log files can be found in the
Illustration 9: Motus OEM Evaluation Kit case
Illustration 10: Motus OEM Evaluation Kit
contents
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same folder as the Motus Manager software.
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8
Part Numbers and Ordering Options
8.1
Evaluation Kit
Part Number
Description
Notes
MOTUS-RUG-EK
Motus Rugged
Evaluation Kit
Motus rugged evaluation kit
Includes items listed in section 6.1
IMU functionality only
AHRS and INS upgrade licenses can be
purchased separately, see section 8.3
MOTUS-OEM-EK
Motus OEM
Evaluation Kit
Motus OEM evaluation kit
Includes items listed in section 7.1
IMU functionality only
AHRS and INS upgrade licenses can be
purchased separately, see section 8.3
Table 4: Evaluation kit part numbers
8.2
Standalone Unit
Part Number
Description
Notes
MOTUS-RUG
Motus Rugged
Unit
Motus rugged unit
No cables included
IMU functionality only
AHRS and INS upgrade licenses can be
purchased separately, see section 8.3
MOTUS-OEM
Motus OEM Unit
Motus OEM unit
No cables included
IMU functionality only
AHRS and INS upgrade licenses can be
purchased separately, see section 8.3
Table 5: Standalone unit part numbers
8.3
Software License Upgrades
These license upgrades can either be ordered with the unit or purchased later and
installed in the field using Motus Manager.
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Part Number
Description
Notes
MOTUS-LIC-AHRS
AHRS license
upgrade for
Motus
Software license upgrade that activates
AHRS functionality of Motus unit.
MOTUS-LIC-INS
INS license
upgrade for
Motus
Software license upgrade that activates
INS functionality of Motus unit.
Table 6: Software license upgrade part numbers
8.4
Accessories
Part Number
Description
Notes
A503-SDC20796
ODU plug to FTDI
USB cable
Motus rugged ODU plug with 2 metres of
cable to FTDI USB plug, see section 9.12
A503-SDC20740-2M
ODU plug with
2m cable
(unterminated)
Motus rugged ODU plug with 2 metres of
unterminated cable, see section 9.11
A503-SDC20753
ODU to D9
connectors and
DC socket
Motus rugged ODU plug with 2 metres of
cable to industry standard D9 connectors
and DC socket, see section 9.13
Table 7: Accessories part numbers
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9
Specifications
9.1
Mechanical Drawings
Illustration 11: Motus rugged mechanical drawings
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9.2
Navigation Specifications
Motus can be upgraded to full AHRS or INS capability through a software license
upgrade. As an INS it can be interfaced to any of the leading brands of GNSS receivers
to create an OEM GNSS/INS solution. When using a Trimble MBTwo receiver, for
example, the following specifications are achievable:
Illustration 12: Motus OEM mechanical drawings
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Parameter
Value
Horizontal Position Accuracy
0.8 m
Vertical Position Accuracy
1.5 m
Horizontal Position Accuracy (RTK)
0.008 m
Vertical Position Accuracy (RTK)
0.015 m
Velocity Accuracy
0.007 m/s
Roll & Pitch Accuracy
0.05 °
Roll & Pitch Accuracy (GNSS aided)
0.03 °
Heading Accuracy (GNSS aided)
0.1 °
Heading Accuracy (dual antenna GNSS)
0.05 °
Orientation Range
Unlimited
Hot Start Time
2 s
Internal Filter Rate
1000 Hz
Output Data Rate
Up to 1000 Hz
Table 8: Navigation specifications
9.3
Sensor Specifications
Parameter
Accelerometers
Gyroscopes
Magnetometers
Range
±10 g
±475 °/s
±8 G
Bias Instability
8 ug
0.4 °/hr
-
Initial Bias
< 1 mg
< 10 °/hr
-
Initial Scaling
Error
< 0.03 %
< 0.02 %
< 0.07 %
Scale Factor
Stability
< 0.04 %
< 0.03 %
< 0.09 %
Non-linearity
< 0.05 %
< 0.03 %
< 0.08 %
Cross-axis
Alignment Error
< 0.05 °
< 0.05 °
< 0.05 °
Noise Density
12 ug/√Hz
7 °/hr/√Hz
210 uG/√Hz
Bandwidth
290 Hz
200 Hz
110 Hz
Table 9: Sensor specifications
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9.4
Rugged Communication Specifications
Parameter
Value
Interface
RS232 (RS422 optional)
Primary and Auxiliary Port Speed
2400 to 2 M baud
GPIO Port Speed
2400 to 250 K baud
Protocol
AN Packet Protocol
NMEA
TSS1
Simrad
Peripheral Interface
2x GPIO and 1x Auxiliary RS232
GPIO Level
5 V or RS232
Table 10: Rugged communication specifications
9.5
OEM Communication Specifications
Parameter
Value
Interface
3.3V TTL serial port (5V tolerant input)
Speed
2400 to 10M baud
Protocol
AN Packet Protocol
Peripheral Interface
2x GPIO and 1x Auxiliary serial port (3.3V
TTL)
GPIO Level
3.3V TTL (5V tolerant input)
Table 11: OEM communication specifications
9.6
Rugged Hardware Specifications
Parameter
Value
Operating Voltage
5 to 36 V
Input Protection
±-60 V
Power Consumption
0.95 W (typical)
Hot Start Battery Capacity
> 48 hrs
Hot Start Battery Charge Time
30 mins
Hot Start Battery Endurance
> 10 years
Operating Temperature
-40 °C to 85 °C
Environmental Sealing
IP67
MIL-STD-810G
Shock Limit
2000 g
Vibration Limit
8 g
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Dimensions (excluding tabs)
42 x 55 x 30 mm
Dimensions (including tabs)
42 x 67 x 30 mm
Weight
72 grams
Table 12: Rugged hardware specifications
9.7
OEM Hardware Specifications
Parameter
Value
Operating Voltage
4.5 to 5.5 V
Input Protection
None
Power Consumption
0.95 W (typical)
Hot Start Battery Capacity
> 48 hrs
Hot Start Battery Charge Time
30 mins
Hot Start Battery Endurance
> 10 years
Operating Temperature
-40 °C to 85 °C
Environmental Sealing
None
Shock Limit
2000 g
Vibration Limit
8 g
Dimensions
31 x 31 x 24 mm
Weight
26 grams
Table 13: OEM hardware specifications
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9.8
Rugged Electrical Specifications
Parameter
Minimum
Typical
Maximum
Power Supply
Input Supply Voltage
5 V
36 V
Input Protection Range
-60 V
60 V
RS232
Tx Voltage Low
-5.7 V
-5 V
Tx Voltage High
5 V
6.2 V
Tx Short Circuit Current
±70 mA
Rx Threshold Low
0.8 V
1.3 V
Rx Threshold High
1.7 V
2.5 V
GPIO
Output Voltage Low
0 V
0.3 V
Output Voltage High
4.8 V
5 V
Output Current
5 mA
Input Voltage
-20 V
20 V
Input Threshold Low
1.5 V
Input Threshold High
3.5 V
Table 14: Rugged electrical specifications
9.9
OEM Electrical Specifications
Parameter
Minimum
Typical
Maximum
Power Supply
Input Supply Voltage
4.5 V
5.5 V
Input Protection Range
None
None
Serial and GPIO Signal Levels
Output Voltage Low
0 V
0.4 V
Output Voltage High
2.4 V
3.3 V
Output Current
10 mA
Input Voltage
0 V
5.5 V
Input Threshold Low
0.8 V
Input Threshold High
2 V
Table 15: OEM electrical specifications
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9.10
Power Consumption
9.11
Rugged Connector Pin-out
Power supply and signal connections are made through a ODU Mini-Snap Series B 9
pin connector. The ODU part number is S30B0SP09MCC00-5000. The connector
provides a reliable and rugged connection to Motus under demanding conditions and is
rated to IP68 in the mated condition. Plugs are supplied with 2 metres of unterminated
shielded cable with an outer protective jacket, part number A503-SDC20740-2M. Each
individual wire is colour coded PFA coated 28AWG wire with an external shield and
insulation. Custom cable lengths can be ordered by request.
Illustration 13: Maximum and typical current consumption across operating voltage
0
5
10
15
20
25
30
35
40
0
20
40
60
80
100
120
140
Maximum
Typical
Voltage (V)
Current Consumption (mA)
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Pin
Colour
Function
1
Black
Ground
2
Brown
Power Supply
3
White
GPIO 1
4
Green
GPIO 2
5
Red
Primary RS232 Transmit
6
Orange
Primary RS232 Receive
7
Yellow
Auxiliary RS232 Transmit
8
Blue
Auxiliary RS232 Receive
9
Pink
Ground
Table 16: Pin allocation table
9.12
Rugged Evaluation Kit USB Cable
The evaluation kit is supplied with a 2 metre cable with a Motus ODU plug on one end
and an overmoulded RS232 to USB converter on the other end, please see Illustration
15. The cable is the same 9 wire cable supplied with unterminated ODU cables and all
9 wires are connected on the ODU end. If required, it is possible to cut off the
overmoulded RS232 converter to get access to all the individual wires. The chip used
in the overmoulded RS232 converter is an FTDI FT232R and supports baud rates of up
to 2,000,000 baud.
Illustration 14: ODU B series mating plug for Motus
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Pin
Colour
Function
RS232 Converter
Connection
1
Black
Ground
USB Ground
2
Brown
Power
USB 5 volt supply
3
White
GPIO 1
4
Green
GPIO 2
5
Red
Primary RS232 Tx
FTDI RS232 Rx
6
Orange
Primary RS232 Rx
FTDI RS232 Tx
7
Yellow
Auxiliary RS232 Tx
8
Blue
Auxiliary RS232 Rx
9
Pink
Ground
Table 17: Evaluation kit USB cable pin-out
9.13
Optional Rugged Breakout Cable
Advanced Navigation offers a pre-terminated breakout cable for access to all of
Motus's pins. All external signal and power connections are provided with 2m of cable.
The interface cable is provided with industry standard 9 pin DSUB connectors for each
of the two RS232 communication channels and GPIO pins. The breakout cable is an
optional extra and is not supplied as standard with the evaluation kit. The part number
is A503-SDC20753.
Illustration 15: Evaluation kit USB cable
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Pin
Colour
Function
Primary
Auxiliary
GPIO
Power
1
Black
Ground
5
5
5
2
Brown
Power
Tip
3
White
GPIO 1
2
4
Green
GPIO 2
3
5
Red
Primary RS232 Tx
2
6
Orange
Primary RS232 Rx
3
7
Yellow
Auxiliary RS232 Tx
2
8
Blue
Auxiliary RS232 Rx
3
9
Pink
Ground
Ring
Table 18: Optional breakout cable connector pin-out
9.14
Sensor Calibration
Motus’s sensors are calibrated for bias, sensitivity, misalignment, cross-axis
sensitivity, non-linearity and gyroscope linear acceleration sensitivity across the full
operating temperature range.
9.15
Serial Number
The serial number can be inspected by using the Device Information dialogue in the
Motus Manager software, see section 12.7.1. The primary serial number label is
Illustration 16: Optional breakout cable diagram
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located inside the enclosure and is accessible only by Advanced Navigation
technicians. The secondary serial number label is located on the outside rear of the
enclosure with the serial number encoded in a 2D data matrix bar code to assist
customers in tracking their units, see Illustration 17. The external label also contains
the hardware version and build date. Applications are available for most smart-phones
that can scan the 2D data matrix bar code to display the serial number.
Illustration 17: Motus external serial
number label
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10
Installation
10.1
Installation Checklist
1. Securely mount the unit to the vehicle following the guidelines in section 10.2.
2. Connect the connector cable to Motus and then connect the USB end to a
computer.
3. Open the Motus Manager software and click connect.
4. If the unit is mounted in an alignment other than the standard alignment of X
pointing forward and Z pointing down, this alignment offset will need to be
entered into the Alignment Configuration dialogue in Motus Manager. Please see
section 10.2.1 for more details.
5. The system is now ready for use.
10.2
Position and Alignment
When installing Motus into a vehicle, correct positioning and alignment are essential to
achieve good performance. There are a number of goals in selecting a mounting site in
your application, these are:
1. Motus should be mounted in an area that is not going to exceed its temperature
range and mounted in a manner that will properly dissipate heat; please contact
[email protected] for advice specific to your application.
2. Motus should be mounted away from vibration where possible.
3. Motus should be mounted close to the centre of gravity of the vehicle where
possible.
4. If the magnetic sensors or magnetic heading are going to be used the Motus
unit should be mounted away from sources of changing magnetic interference
such as high current wiring, motors, moving steel masses and rotating or
reciprocating machinery.
10.2.1
Alignment
The easiest way to align Motus is by installing it with the sensor axes aligned with the
vehicle axes. This means that the X axis points forward towards the front of the
vehicle and the Z axis points down towards the ground.
If aligning Motus with the vehicle axes is not possible or not optimal, it may be
mounted in a different alignment and the alignment offset should be configured using
the Alignment configuration dialogue in Motus Manager, see section 12.8.4. For easy
alignment, the set zero orientation button in the Motus Manager Alignment
configuration dialogue can be used to set the current orientation as the zero
orientation alignment, see section 12.8.4. Please note that this will only correct for roll
and pitch offsets. Any heading offset will need to be entered manually and saved
before using this function.
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10.3
Mounting Plate
Motus's mounting plate and hole guide is shown below in Illustration 18. The holes are
designed for M4 bolts. The alignment holes can be used to ensure precise alignment of
Motus through the use of alignment pins.
10.4
Power Supply
A high level of power supply filtering has been built into Motus to allow for reliable
operation in demanding environments. Motus contains a fully isolated power supply
and has separate grounds for power and signal to ensure that power supply noise does
not corrupt communications or cause ground loops with other equipment. When wiring
the system, the signal ground should be routed with the primary RS232, auxiliary
RS232, GNSS RS232 and GPIO pins. The power ground should be routed with the
power supply to the power source.
A power supply should be selected that can provide at least the maximum current
calculated from the graph in 9.10.
Motus contains an active protection circuit on the power supply input that protects the
Illustration 18: Motus mounting plate
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unit from under-voltage, over-voltage and reverse polarity events. The protection
circuit shuts off power and automatically recovers the unit to full operation once the
fault is removed. Take care when running the unit close to its under-voltage lockout of
4.2 V because small voltage drops can engage the under-voltage shutdown and
potentially oscillate between the on and off state. It is recommended that the unit is
always run at 5 V or more to avoid issues associated with this.
10.5
Odometer
On ground vehicles, the use of an odometer input can greatly improve Motus’s
navigation and orientation solution during GNSS dropouts. With a high resolution
wheel encoder Motus can be used to navigate indoors with GNSS disabled altogether.
There are several different options for odometer installation which are listed below.
10.5.1
Factory VSS Signal
Most road cars since 1980 contain a VSS (vehicle speed sensor) signal that can be
wired directly into one of Motus’s GPIO pins. The vehicle should be taken to an
automotive electrician to perform the work.
To setup the odometer, the appropriate GPIO pin should be set to odometer input
using Motus Manager, see section 12.8.6. The odometer pulse length must then be set
either manually or automatically, please see section 11.8 for more information.
For more information on the GPIO signals and their requirements please see section
15.4.3.
10.5.2
OBDII Odometer Interface
For applications where it is undesirable to modify the vehicle or the system needs to
be used with multiple vehicles, the OBDII odometer interface may be a better solution.
OBDII is a vehicle diagnostic port standard and most vehicles from the mid 1990s
onwards contain an OBDII port in the drivers side foot well. Advanced Navigation
produces an OBDII odometer interface that plugs into this OBDII port and feeds Motus
with odometer data over the Auxiliary RS232 port, please see Illustration 19. These
units are priced at approximately AUD 500. Please contact Advanced Navigation sales
for more information.
Illustration 19: Advanced Navigation OBDII Odometer
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10.5.3
Aftermarket Wheel Speed Sensor
Applications requiring very high performance are recommended to use a high
precision aftermarket wheel speed sensor. Advanced Navigation recommends
aftermarket wheel speed sensors from Pegasem or GMH Engineering.
10.5.4
Radar Speed Sensor
For applications requiring high performance in harsh conditions where aftermarket
wheel speed sensors are not feasible, a radar speed sensor is recommended.
Advanced Navigation recommends radar speed sensors from Stalker or GMH
Engineering.
Illustration 20:
Aftermarket wheel
speed sensor
Illustration 21: Radar
speed sensor
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10.6
Magnetics
Motus contains magnetometers which it uses to measure the Earth's magnetic field in
order to determine its heading. The principle is the same as that of a compass. When
operating Motus with magnetic heading enabled, sources of magnetic interference can
degrade Motus’s solution if not compensated for. There are two types of magnetic
interference, these are static and dynamic.
Static magnetic interference is caused by steel and other magnetic materials mounted
in the vehicle. Static disturbances are easily compensated for by running a magnetic
calibration, see section 11.5. A magnetic calibration should always be run after
installation into a vehicle.
Dynamic magnetic interference is generally a much bigger issue. Sources of dynamic
magnetic interference include high current wiring, electric motors, servos, solenoids
and large masses of steel that don't move with Motus. Motus should be mounted as far
as possible from these interference sources.
Motus contains a special algorithm to remove the effects of dynamic magnetic
interference. This is able to compensate for most typical interference sources
encountered, however certain types of prolonged dynamic interference cannot be
compensated for. The best way to check for dynamic magnetic interference is to use
the raw sensors view in Motus Manager and watch the magnetometer outputs whilst
the vehicle is operating but stationary, see section 12.7.4. The values should be
constant, if the values are fluctuating there is dynamic magnetic interference present.
If dynamic magnetic interference is causing performance problems and there is no
way to mount Motus away from the interference source, the magnetometers should be
disabled, see section 11.5.4.
10.7
Vibration
Motus is able to tolerate a high level of vibration compared to other inertial systems.
There is however a limit to the amount of vibration that Motus can tolerate and large
levels of vibration will cause Motus's accuracy to degrade.
When mounting Motus to a platform with vibration there are several options. It is
recommended to first try mounting Motus and see whether it can tolerate the
vibrations. The raw sensor view in the Motus Manager software can give you a good
idea of how bad the vibrations are. If the vibrations are causing the sensors to go over
range you will need to take preventative steps against the vibration.
If Motus is unable to tolerate the vibrations there are several options:
1. Try to find a mounting point with less vibration.
2. Motus can be mounted on top of a small flat piece of rubber. Please note that
this may cause small changing orientation errors due to flexing of the rubber.
3. Motus can be mounted to a plate which is then mounted to the platform through
vibration isolation mounts.
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11
INS and AHRS Operation
11.1
Initialisation
There are four different levels of initialisation on Motus. These are orientation,
navigation, heading and time. The initialisation can be monitored by inspecting the
status view in Motus Manager, see section 12.7.2.
After all four levels of initialisation, Motus's filter takes several minutes to achieve it's
full accuracy. It is recommended to wait two minutes after initialisation for applications
requiring high accuracy.
11.1.1
Orientation Initialisation
Orientation initialisation occurs automatically upon power on and typically completes
within several seconds. Once orientation initialisation is complete, the roll, pitch and
angular velocity values will be valid.
When Motus starts up, it assumes that it can be in any orientation. To determine it's
orientation it uses the accelerometers to detect the gravity vector. Whilst this is
occurring, if there are random accelerations present, these can cause an incorrect
orientation to be detected. To prevent this, Motus monitors the accelerometers and
gyroscopes and restarts the orientation detection if there are sudden movements. It is
however still possible under some circumstances for it to miss minor movements and
start with a small orientation error. In this scenario Motus will progressively correct the
orientation error over a period of several seconds.
11.1.2
Navigation Initialisation
Please note that when operating Motus with the IMU or AHRS license, navigation will
not initialise.
Navigation initialisation completes once the system has determined a starting
position. The most common method of navigation initialisation is for the system to get
a 3D GNSS fix from a connected GNSS receiver. If the system is hot starting it will
remember it's position from when it was switched off and use this as the starting
position. The other possibility for navigation initialisation is an external position
Illustration 22: The
four initialisation
levels
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source, see section 15.2 for more information. In a situation where a GNSS fix is not
available to initialise navigation, it can be initialised manually by entering a position
into the Manual Initialisation dialogue in Motus Manager, see section 12.8.11.
Once navigation initialisation is complete, the position, velocity and acceleration
values will be valid.
11.1.3
Heading Initialisation
Heading initialisation completes once the system has determined a heading. The
conditions required to determine a heading depend upon the heading source being
used, see section 11.4. If magnetic heading is enabled as a heading source the
heading initialisation should complete within 2 seconds after power on. If magnetic
heading is disabled and velocity heading is used as the only heading source, the
heading will initialise once the system travels at a speed of over 1.15 metres/second
for over 5 seconds with a 3D GNSS fix or other source of velocity information. If the
system is hot starting it will remember it's heading from when it was switched off and
use this as the starting heading until another source becomes available.
Until the heading has been initialised, the system will not be able to navigate without
a GNSS fix or other position source and the roll and pitch values will not be able to
reach full accuracy.
11.1.4
Time Initialisation
Time initialisation completes once the system has determined time accurately. For this
to occur the system must receive rough time as well as a 1PPS signal on one of the
GPIO pins. The rough time is typically received from a GNSS receiver when it achieves
a fix. It is also possible to provide an external source of time, see section 15.2 for more
information on external time sources.
Until the time has initialised the values of Unix time and formatted time that Motus
outputs will not be valid and may change.
11.2
Hot Start
Motus is the first GNSS/INS on the market with hot start functionality. This allows
Motus to start inertial navigation within 2 seconds. Motus's hot start is always on and
fully automatic.
A next generation backup battery system within Motus provides the hot start ability for
more than 48 hours without power. When Motus hot starts it assumes that it is in the
same state it was when it lost power and begins navigating from that position. When
the GNSS achieves it's first fix, if this position deviates from the hot start position,
Motus will jump to the new position without causing any side effects to the filter.
Whilst Motus is without power it keeps track of the time accurately to within 1 second
so that the time is immediately valid on a hot start.
Motus's hot start is of particular benefit to vehicle tracking and robotics applications.
The primary benefits are immunity and fast recovery from power failure as well as fast
startup time.
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11.3
Time
Motus was designed to provide a highly accurate time reference. When a GNSS fix is
available Motus's time is accurate to within 50 nanoseconds. When a GNSS fix is lost,
Motus's time accuracy typically remains within 10 microseconds over extended time
periods. When Motus hot starts the time accuracy is typically within 1 second
immediately on startup and corrected to within 50 nanoseconds as soon as a GNSS fix
is achieved and 1PPS received. To synchronise with Motus's high accuracy time, both
the packet protocol and a 1PPS line must be used.
11.4
Heading Source
There are three different heading sources available for Motus. By default Motus uses
both magnetic heading and velocity heading. It is possible to use multiple heading
sources and this will often provide performance benefits.
11.4.1
Magnetic Heading
This is the default heading source and works well in the majority of cases. When using
magnetic heading, calibration is required every time Motus's installation changes. The
downside of magnetic heading is that prolonged dynamic magnetic interference
sources can cause heading errors.
11.4.2
Velocity Heading
Velocity heading works by deriving heading from the direction of velocity and
acceleration. Velocity heading works well with cars, boats, fixed wing aircraft and other
vehicles that don't move sideways. Velocity heading does not work with helicopters
and other 3D vehicles. The downside of velocity heading is that heading can not be
measured until the vehicle moves at a horizontal speed of over 1.15 metres/second
with a GNSS fix. The benefits of velocity heading are that it is immune to magnetic
interference and no calibration is required when Motus's installation changes.
11.4.3
External Heading
External heading can be used if there is some other way to derive heading that is
external to Motus. Examples include dual antenna GNSS systems, gyro-compasses,
reference markers and SLAM systems. The heading must be fed into Motus using the
External Heading Packet or through NMEA into a GPIO pin.
11.5
Magnetics
Static magnetic interference is defined as anything that provides a fixed vector of
magnetic interference to Motus, an example would be the steel body of a car that
Motus is mounted on. Dynamic magnetic interference is defined as anything that
provides varying magnetic interference, an example would be when Motus is mounted
on an engine and the pistons within are moving relative to Motus and providing a
changing magnetic field.
Static magnetic interference is resolved through magnetic calibration and dynamic
magnetic interference is compensated by a filter algorithm but should be minimised
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where possible through installation location. To compensate for static magnetic
interference, magnetic calibration should be performed any time Motus's installation
changes.
Motus contains a dynamic magnetic compensation filter that is able to mitigate the
effects of short term magnetic interference sources while in operation. For example if
Motus is installed in a car and the car drives over a large piece of magnetised steel,
this will be compensated for. Another example is driving through a tunnel which is built
from heavily reinforced concrete. It is important to note that for Motus's dynamic
magnetic compensation filter to operate correctly, Motus needs to get a GNSS fix at
least once every time it is moved more than 50km. Each time Motus moves more than
50km the new position is stored permanently and allows Motus to update it's world
magnetic model values.
There are three types of magnetic calibration available, these are 2D calibration, 3D
calibration and automatic calibration. 2D calibration involves one level rotation about
the Z axis and is designed for vehicles that cannot easily or safely be turned upside
down, such as full size cars, planes and boats. 3D calibration involves rotating through
all orientations and is designed for vehicles that can easily and safely be rotated
upside down, such as model size vehicles. 3D calibration offers slightly better
performance and is recommended where possible. Automatic magnetic calibration
continuously and automatically calibrates for static magnetic interference while the
unit is in operation. It is not as accurate as the 2D or 3D calibration, however it is very
convenient for applications where Motus needs to just work without user intervention.
Please note that if Motus is going to be used in a vehicle, the calibration should be
performed while Motus is mounted in and fixed to that vehicle. This means that the
whole vehicle must be moved to perform the calibration. The calibration needs to be
performed in an area away from sources of magnetic interference. For example if
Motus is installed in a car, the calibration should not involve driving over steel drains
or reinforced concrete etc. If Motus is being calibrated to operate standalone, the
calibration should not be done on a desk with a steel frame.
11.5.1
2D Magnetic Calibration
The following procedure should be used to perform a 2D magnetic calibration.
11.5.1.1
Using the Motus Manager Software
1. The unit should be powered on while the vehicle is in a level orientation and
kept stationary.
2. After power on wait 5 minutes for the temperature and filter to stabilise.
3. Open Motus Manager and connect to the device. Ensure that the device has
either a GNSS fix or the position has been manually entered in the Manual
Initialisation window before proceeding.
4. In the Tools menu, open Magnetic Calibration. Click the 2D Calibration button.
See section 12.9.1.
5. Whilst keeping as level as possible, rotate the vehicle in either direction through
one and a quarter full rotations. In a car this can be achieved by driving in one
and a quarter circles.
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6. Check the status in the Magnetic Calibration window to ensure that the
calibration completed successfully. If not successful click Cancel, wait 2 minutes
and repeat from step 4. Do not press the save button in the lower half of the
dialogue, this will over write the new calibration values. The calibration values
are automatically saved internally.
11.5.1.2
Using the Packet Protocol
1. The unit should be powered on while the vehicle is in a level orientation and
kept stationary.
2. After power on wait 5 minutes for the temperature and filter to stabilise.
3. Ensure that the device has a position fix, either from an external GNSS receiver,
or using the External Position and Velocity packet #44 or the External Position
packet #45, before proceeding.
4. Send the Magnetic Calibration Configuration Packet with the action Start 2D
Magnetic Calibration.
5. Whilst keeping as level as possible, rotate the vehicle in either direction through
one and a quarter full rotations. In a car this can be achieved by driving in one
and a quarter circles.
6. Read the Magnetic Calibration Status Packet to ensure that the calibration
completed successfully. If not successful, send the Magnetic Calibration
Configuration Packet with the action Cancel, wait 2 minutes and repeat from
step 4.
11.5.2
3D Magnetic Calibration
The following procedure should be used to perform a 3D magnetic calibration.
11.5.2.1
Using the Motus Manager Software
1. The unit should be powered on and the vehicle kept stationary.
2. After power on wait 5 minutes for the temperature and filter to stabilise.
3. Open Motus Manager and connect to the device. Ensure that the device has
either a GNSS fix or the position has been manually entered in the Manual
Initialisation window before proceeding.
4. In the Tools menu, open Magnetic Calibration. Click the 3D Calibration button.
See section 12.9.1. The following steps 5, 6 and 7 can be performed in any
order.
5. Slowly rotate the vehicle twice around the X axis (roll).
6. Slowly rotate the vehicle twice around the Y axis (pitch).
7. Slowly rotate the vehicle twice around the Z axis (heading).
8. Check the status in the Magnetic Calibration window to ensure that the
calibration completed successfully. If not successful click Cancel, wait 2 minutes
and repeat from step 4. Do not press the save button in the lower half of the
dialogue, this will over write the new calibration values. The calibration values
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are automatically saved internally.
11.5.2.2
Using the Packet Protocol
1. The unit should be powered on and the vehicle kept stationary.
2. After power on wait 5 minutes for the temperature and filter to stabilise.
3. Ensure that the device has a position fix, either from an external GNSS receiver,
or using the External Position and Velocity packet #44 or the External Position
packet #45, before proceeding.
4. Send the Magnetic Calibration Configuration Packet with the action Start 3D
Magnetic Calibration. The following steps 5, 6 and 7 can be performed in any
order.
5. Slowly rotate the vehicle twice around the X axis (roll).
6. Slowly rotate the vehicle twice around the Y axis (pitch).
7. Slowly rotate the vehicle twice around the Z axis (heading)
8. Read the Magnetic Calibration Status Packet to ensure that the calibration
completed successfully. If not successful, send the Magnetic Calibration
Configuration Packet with the action Cancel, wait 2 minutes and repeat from
step 4.
11.5.3
Automatic Magnetic Calibration
Automatic magnetic calibration is an algorithm that continuously and automatically
calibrates for static magnetic interference. Automatic magnetic calibration is enabled
by default and it is recommended to keep it enabled for all vehicle types. When used
on top of a 2D or 3D calibration it can give the best results from magnetic heading.
Every time Motus is powered on in a cold start (48 hours without power) the automatic
calibration is reset. The automatic magnetic calibration starts operating when Motus is
travelling at a speed over 5 m/s with a GNSS fix and velocity heading turned on.
Automatic magnetic calibration is not as accurate as 2D or 3D calibration, however it
is sufficient for most vehicles and allows Motus to be installed into vehicles and
operated without user intervention. Automatic magnetic calibration can be turned off
using the Filter Options dialogue in Motus Manager, see section 12.8.2.
11.5.4
Disabling Magnetometers
In situations where there is very strong dynamic magnetic disturbances present, it is
recommended to disable the magnetometers. When the magnetometers are disabled
a secondary heading source is required otherwise may become inaccurate. Velocity
heading is the recommended source. Please see section 11.4 for information on
heading sources. The magnetometers can be disabled using the Filter Options dialogue
in Motus Manager, see section 12.8.2.
11.6
Data Anti Aliasing
Internally Motus's filters update at 1000 Hz. When Motus outputs data, most
applications require the data at a much lower rate (typically < 100 Hz). This causes a
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problem for time based data such as velocities and accelerations where aliasing will
occur at the lower rate. To prevent this problem, if the output rate is lower than 1000
Hz, Motus will low pass filter the values of the time dependent data between packets
to prevent aliasing. This is only the case when a packet is set up to output at a certain
rate. If the packet is simply requested no anti aliasing will occur. Additionally there is
no anti aliasing for non time dependent fields such as position.
11.7
Vehicle Profiles
Motus supports a number of different vehicle profiles. These vehicle profiles impose
constraints upon the filter that can increase performance. If your application matches
one of the available vehicle profiles, it is recommended to select it for use in the Filter
Options dialogue in Motus Manager, see section 12.8.2. For a list of the different
vehicle profiles please see section 16.10.5.1. Please note that if the wrong vehicle
profile is selected it can cause a significant decrease in performance.
11.8
Odometer Pulse Length
For Motus to use a wheel speed sensor or odometer input, it must know the pulse
length of the signal. The pulse length is the distance in metres between low to high
transitions of the signal. The odometer pulse length can either be entered manually or
automatically calibrated by Motus. To enter the pulse length manually, please use the
Odometer configuration dialogue in Motus Manager, see section 12.8.7. To
automatically calibrate the odometer pulse length please use the procedure listed
below in section 11.8.1. By default the odometer will automatically calibrate itself.
11.8.1
Odometer Automatic Pulse Length Calibration Procedure
1. Ensure that the signal is connected correctly and that the GPIO pin is configured
as an odometer input using the GPIO configuration dialogue in Motus Manager,
see section 12.8.6.
2. Open Motus Manager, connect to Motus and open the Odometer configuration
dialogue. In the Odometer configuration dialogue tick the automatic pulse
length calibration check box and press the write button, see section 12.8.7.
3. Wait until Motus has a continuous GNSS fix and then drive 1000 metres over flat
terrain with as little turning as possible.
4. If Motus loses a GNSS fix for any extended period of time during the calibration,
the distance travelled will be reset. The distance travelled can be checked in the
Odometer configuration dialogue to ensure that it has passed 1000 metres.
5. Once 1000 metres has been driven, press the read button and check that the
automatic pulse length check box becomes un-ticked and the pulse length value
is read.
11.9
Reversing Detection
Reversing detection is an algorithm that can detect when the vehicle is travelling in
reverse. Knowledge of reverse motion is important when using velocity heading or
odometer input to provide correct results. If Motus is fitted to a vehicle that does not
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reverse or doesn't use velocity heading or odometer, this function should be disabled.
Reversing detection is enabled by default and it can be disabled using the Filter
Options dialogue in Motus Manager, see section 12.8.2.
11.10
Motion Analysis
Motion analysis is an artificial intelligence algorithm that associates patterns in high
frequency inertial data with the speed of the vehicle. After power on it takes some
time to match patterns with speed before it will become active. Motion analysis only
activates when dead reckoning and is most effective when the vehicle is near
stationary. Motion analysis does not work in all situations and it's primary benefit is in
ground vehicles. When active it can be recognised by 2Hz steps in velocity data.
Motion analysis is disabled by default and can be enabled using the Filter Options
dialogue in Motus Manager, see section 12.8.2.
11.11
Heave
Motus can provide vertical heave position at four different points on a ship. Motus's
heave filter is always on and fully automatic. After power on, Motus requires
approximately 5 minutes for it's heave filter to converge upon an accurate solution.
Heave works without a GNSS fix, however best heave performance is achieved when
Motus has a GNSS fix.
By default Motus provides heave from the point at which the Motus unit is mounted,
however it can provide heave at four different offset points on the ship. To set the
heave offsets, use the Reference Position Offsets dialogue in Motus Manager, see
section 12.8.9.
11.12
Environmental Exposure
Whilst Motus Rugged is environmentally protected, there are clearly defined limits to
this protection that must be adhered to for reliable operation.
Motus Rugged is only protected when it's connector is mated. When any of these
connections are not made the unit offers no environmental protection.
Spanners or tools should never be used to tighten the connectors. They should only
ever be finger tight.
11.12.1
Temperature
Motus should not be subjected to temperature's outside of it's operating range.
Subjecting Motus to temperature's outside of the storage range can cause failure of
the system and or effect the factory sensor calibration which will cause a permanent
performance degradation.
If the temperature rises above 90 degrees Celsius, Motus will automatically shut off
power to its sensors in an attempt to prevent damage, this will also send the filters
into reset.
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11.12.2
Water
Motus Rugged is water-proof to the IP67 standard which means that it can be
submersed in water to a depth of up to 1 metre only. Submersion to depths beyond 1
metre can cause water entry and destruction of the internal electronics.
11.12.3
Salt
Motus Rugged is made from marine grade aluminium which gives it reasonably good
salt water corrosion resistance. However Motus Rugged cannot tolerate extended
periods of time in salt water environments. After any contact with salt water
environments, Motus Rugged should be thoroughly rinsed with fresh water.
11.12.4
Dirt and Dust
Motus Rugged is completely sealed against dirt and dust entry. It is important to note
that this is only the case when the connectors are mated. When un-mating the
connectors if the Motus Rugged unit is dirty or dusty, the dirt should be rinsed off with
fresh water first and then dried off. This is to prevent dirt or dust entering the
connectors which can cause them to fail.
11.12.5
PH Level
Environments with a high or low PH level can cause the Motus Rugged enclosure to
corrode. If Motus Rugged comes into contact with these environments it should be
rinsed in fresh water as soon as possible. It is not recommended to operate Motus
Rugged in non neutral PH environments.
11.12.6
Shocks
Motus can tolerate shocks to 2000g, however continuous shocks of this severity are
likely to cause premature failure. Shocks above 2000g can effect the factory sensor
calibration and degrade performance. Normally shocks to Motus when mounted in a
vehicle are fine. Even a high speed car crash is likely to reach a peak of only 50g.
Shocks directly to Motus Rugged's enclosure can more easily go over the limit however
so care should be taken when handling the unit prior to mounting.
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12
Motus Manager
Motus Manager is a software tool provided by Advanced Navigation for logging,
testing, display and configuration of Motus. It is designed to be simple and easy to
use.
Illustration 23: Screenshot of Motus Manager
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12.1
Software Changelog
Version
Date
Changes
4.3
08/03/2016
Initial Release
12.2
System Requirements
The software includes a 3D mapping display which requires a modern 3D graphics card
and up to date drivers to run. If your machine does not meet the graphics
requirements the mapping view will only show space without a globe.
When Motus is running at very high output rates e.g. 1000 Hz, Motus Manager can
consume significant system resources handling the large quantity of data.
12.3
Installation
Motus Manager does not need to be installed and can be run from any directory by
double clicking on it. Motus Manager requires a recent version of Java, available at
http://www.java.com. On some systems to open the program it may be necessary to
right click and select open with → Java Runtime Environment.
The Motus evaluation kit makes use of an FTDI USB to RS422 device. The drivers are
normally installed automatically, if not they are available from
http://www.ftdichip.com/Drivers/VCP.htm.
12.4
Troubleshooting
Please contact [email protected] if you are having issues.
12.4.1
All Platforms
If the globe does not appear in the 3D map area, this indicates that either your
graphics card is not powerful enough or your graphics card driver is out of date.
12.4.2
Windows
There is a well known problem with USB serial devices under Windows known as
“crazy mouse”. The problem occurs when the system mistakenly installs the USB
serial device as a mouse. Unfortunately Microsoft has not fixed this problem in over 15
years, so it probably won't be fixed. If you experience this problem, often a restart will
resolve it. Otherwise there is a tool available at
http://www.stentec.com/anonftp/pub/wingps/pnpblockersetup.exe that can fix the
issue.
If the serial port does not show up when you plug in your Motus USB device, you may
need to install the drivers from http://www.ftdichip.com/Drivers/VCP.htm.
If you experience a blue screen of death whilst using Motus Manager, this is typically a
problem associated with older FTDI drivers. To resolve the problem, install the latest
drivers from http://www.ftdichip.com/Drivers/VCP.htm.
When operating Motus at a very high data rate, data can be lost due to the latency of
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the FTDI driver. To resolve this problem the latency of the driver should be reduced by
going to control panel → system → device manager → ports and right click on the USB
serial port, then click properties. In the properties window click the port settings tab
and then the advanced button. You then need to change the latency timer setting to
1ms. Please see the screenshot in Illustration 24.
12.4.3
Linux
If serial ports do not show up, the typical cause is permissions. The user should add
themselves to the dialout group with the command sudo adduser username dialout.
Compiz causes issues with the 3D mapping. If you are experiencing problems it is
Illustration 24: Screenshot of latency timer setting
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recommended to turn off compiz.
Modemmanager can also sometimes cause problems on Linux installations. If you are
not using a modem, it is recommended to remove modemmanager with the command
sudo apt-get remove modemmanager.
Motus Manager is able to run on the OpenJDK JRE but it uses significantly more system
resources than when it is running on the Oracle JRE.
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12.5
Main View
12.5.1
Serial Port
The Serial Port list is used to connect to Motus. You should select a serial port and
baud rate and click connect. The default baud rate of Motus is 115200. The Connection
Indicator displays whether there is communication with a Motus unit.
12.5.2
Attitude Indicator
The aircraft style Attitude Indicator shows roll and pitch through a virtual horizon.
Around the sides heading, speed and height are shown. All units are SI (metric) and
degrees.
12.5.3
Status Indicator
The Status indicator section contains a Motus status indicator, a fix indicator and a
Illustration 25: Screenshot of Motus Manager main view
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satellites table.
12.5.3.1
Motus Status Indicator
This indicator shows any problems with Motus. Before a GNSS fix is achieved it will
show the status “Filter not initialised”. Once the filter has initialised it should show
“Healthy”. Clicking on the indicator will show the detailed status flags.
12.5.3.2
Fix Indicator
This shows the status of the GNSS fix. Under normal operating conditions it should
show either “3D Fix” or “SBAS Fix”. When satellite visibility is poor it may show either
“2D Fix” or “No Fix”.
12.5.3.3
Satellites Table
The Satellites table shows the number of active satellites being used in the current
GNSS solution. More detailed information can be found in the satellites view.
12.5.4
3D Map
The 3D map shows Motus's position on the Earth as well as a red trail of position
history. When the filter initialises the map will automatically reset the view to Motus's
location. To move the camera click and drag on the map. To zoom in and out use the
scroll wheel. To change the camera view right click and drag or shift click and drag.
12.5.5
3D Map Controls
12.5.5.1
Reset View
This resets the map view to Motus's current position.
12.5.5.2
Clear History
This clears the current position history, this is the red trail shown on the map.
12.6
Logging
Motus Manager features a fully automatic logging system. Every time the serial port
connect button is clicked Motus Manager starts a new log file in either the current
directory or the user's home directory. The log file is given the file name
MotusLog_date_time.anpp and contains all of the raw data received from Motus in the
AN packet protocol. The log files are closed when the serial port is disconnected. To
convert these log files into easily accessible formats, the Log Converter dialogue in the
Tools menu can be used, see section 12.9.3. The Log Converter dialogue creates a
folder and generates files in the CSV (comma separated values) format that can be
easily opened with Microsoft Excel, Matlab, libreoffice and most other data analysis
programs. It also creates a GPX file of position that is designed to be opened with
Google Earth.
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12.7
View
The View menu contains a number of different options for viewing data from Motus.
12.7.1
Device Information
Illustration 26: Screenshot showing log file and log conversion folder
Illustration 27: Screenshot of Motus
Manager View menu
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12.7.2
Status
Status shows Motus's complete status as contained in the system state packet
detailed in section 16.9.1.1.
Illustration 28: Screenshot of Motus Manager
Device Information dialogue
Illustration 29: Screenshot of Motus Manager Status dialogue
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12.7.3
Satellites
Satellites shows detailed information on the satellites that Motus's GNSS receiver is
tracking. Elevation and azimuth are in units of degrees.
Illustration 30: Screenshot of Motus Manager Satellites dialogue
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12.7.4
Raw Sensors
Raw sensors shows the temperature calibrated raw sensor values.
Illustration 31: Screenshot of Motus Manager Raw Sensors dialogue
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12.7.5
Orientation
Orientation shows Motus's orientation, angular velocity and orientation error.
Illustration 32: Screenshot of Motus Manager Orientation
dialogue
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12.7.6
Position
Position shows Motus's position and position error. Latitude and longitude are
converted to North and East metres from a reference point that can be reset.
Illustration 33: Screenshot of Motus Manager Position dialogue
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12.7.7
Velocity and Acceleration
Velocity and Acceleration shows Motus's velocity, acceleration and g-force.
Illustration 34: Screenshot of Motus Manager Velocity and
Acceleration dialogue
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12.7.8
3D Model
This dialogue shows a real-time 3D model of Motus's orientation.
Illustration 35: Screenshot of Motus Manager 3D Model
dialogue
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12.7.9
Communications Statistics
This dialogue shows statistics on the data packets received from Motus and can be
useful in diagnosing signal integrity problems.
12.7.10
Heave
For the Heave dialogue to function the heave packet (ID 58) must be set to output
periodically using the Packet Rates dialogue.
Illustration 36: Screenshot of Motus
Manager Communications Statistics
dialogue
Illustration 37: Screenshot of Motus Manager Heave dialogue
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12.8
Configuration
The Configuration menu contains a number of dialogues for the configuration of
Motus.
12.8.1
Configuration Export
The Configuration Export dialogue can be used to export all Motus settings to a file.
This file can be imported at a later date or on other units. This is useful to restore a
unit to preset configuration at a later date or for batch configuration of multiple units.
Illustration 38: Screenshot of Motus Manager
Configuration menu
Illustration 39: Screenshot of Motus Manager Configuration
Export dialogue
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12.8.2
Filter Options
For most applications the default filter options should be used and only the vehicle
profile set. If in doubt please contact [email protected].
Illustration 40: Screenshot of Motus Manager
Filter Options dialogue
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12.8.3
Packet Rates
The Packet Rates dialogue allows the user to specify which packets output on a
periodic basis and at what rate. The default packets enabled are the System State
Packet (ID 20) and the Raw Sensors Packet (ID 28) at 20Hz and these typically provide
all the data that a user will require. These two packets need to be enabled for the data
graphs to update in Motus Manager. Other state packets can be enabled as required.
Please see the Packet Summary table in section 16.7 for a list of all packets.
Illustration 41: Screenshot of Motus Manager Packet
Rates dialogue
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12.8.4
Alignment Configuration
The Alignment configuration dialogue is used to set the alignment offsets of the
system installation. It is important to set the values in this dialogue correctly for
accurate results. For most applications only the GNSS antenna offset values need to be
entered and the rest of the values can be left at their factory defaults of zero.
12.8.4.1
Alignment Offset
If Motus is installed into the vehicle with the X axis pointing forwards and the Z axis
pointing down, then no alignment offset is required and the roll, pitch and heading
offset values can remain at the factory defaults of zero.
If the unit is installed in a different orientation then the roll, pitch and heading offset
must be entered. For example if the unit is installed on its side with the X axis pointing
up and the Z axis pointing forwards and no change to the Y axis, then this would result
in a pitch offset of +90 degrees with roll and heading remaining zero.
If there is a small misalignment due to mechanical mounting error this can be
compensated for by setting the vehicle stationary on a level surface and pressing the
zero current orientation button. Please note that this will only correct for roll and pitch
offsets, the heading offset must be entered manually and saved before using this
function.
All the other offsets will be measured in the realigned body co-ordinate frame (X
positive forward, Z positive down) after being corrected for any alignment offset
entered.
Illustration 42: Screenshot of Motus Manager Alignment
configuration dialogue
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12.8.4.2
GNSS Antenna Offset
The GNSS antenna offset is measured from the centre of the Motus unit to the centre
of the antenna in the body co-ordinate frame (X positive forward, Z positive down).
12.8.4.3
Odometer Offset
The odometer offset is measured from the centre of the Motus unit to the point at
which the vehicle's tyre makes contact with the road in the body co-ordinate frame (X
positive forward, Z positive down).
12.8.4.4
External Data Offset
These values are only required for speciality applications operating with external
sources of data. Please contact [email protected] for assistance with
these values.
12.8.5
Baud Rates
When changing baud rates, some Microsoft Windows machines are unable to function
at the higher baud rates. It is recommended to test the baud rate first with the
Permanent box unticked. This way, if it is not possible to communicate at the higher
baud rate, a power cycle can be used to revert to the previous baud rate.
Illustration 43: Screenshot
of Motus Manager Baud
Rates dialogue
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12.8.6
GPIO Configuration
This dialogue allows the user to select the function of the GPIO pins and Auxiliary
RS232. These functions change dynamically and are effective immediately upon
pressing save. Please note that GPIO pins function at RS232 levels for data functions
and 0 to 5 volt levels for all other functions. The internal hardware automatically
reconfigures based upon the selected function.
12.8.7
Odometer
The Odometer dialogue allows the user to configure the odometer pulse length and
view the real time odometer data to verify correct operation.
Illustration 44: Screenshot of Motus Manager GPIO
configuration dialogue
Illustration 45: Screenshot of Motus
Manager Odometer configuration
dialogue
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12.8.8
Reset
The reset button causes the system to perform a power cycle as if the unit had the
power removed and reapplied. The factory restore button causes the system to erase
all settings and restore factory defaults. It also erases the hot start data so that the
system is forced to perform a cold start.
12.8.9
Reference Position Offsets
The Reference Position Offsets dialogue allows the user to move the heave
measurement points to different positions on the vessel. When the values are zero the
measurement point is the centre of the Motus unit. This can be offset to a different
position on the ship by entering the offset value from the centre of the Motus unit to
the desired position in the body co-ordinate frame (X positive forwards, Z positive
down). Please note that these values only apply to the Heave Packet. NMEA, TSS and
Simrad heave is not affected by the values in this dialogue which are always measured
at the centre of the Motus unit.
Illustration 46:
Screenshot of Motus
Manager Reset dialogue
Illustration 47: Screenshot of Motus Manager Reference Position
Offsets dialogue
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12.8.10
GPIO Output
The GPIO Output configuration dialogue allows the user to configure the output rates
for the GPIO and Auxiliary RS232 data functions NMEA, TSS and PASHR.
Illustration 48: Screenshot of Motus
Manager GPIO Output configuration
dialogue
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12.8.11
Manual Initialisation
This dialogue can be used to manually initialise Motus when a GNSS fix is not
available. Setting the position will initialise the navigation filter. Setting the heading
will initialise the heading.
12.9
Tools
The Tools menu contains tools for performing procedures with Motus.
Illustration 49: Screenshot of
Motus Manager Manual
Initialisation dialogue
Illustration 50: Screenshot of Motus Manager
Tools menu
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12.9.1
Magnetic Calibration
The Magnetic Calibration dialogue allows the user to perform magnetic calibration as
well as view and modify the magnetic calibration values. The actual magnetic
calibration is performed inside the Motus unit. This dialogue does not have any smarts,
it is just a control and display interface.
Illustration 51: Screenshot of Motus Manager
Magnetic Calibration dialogue
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12.9.2
Firmware Update
The Firmware Update dialogue is used to update Motus's firmware. Advanced
Navigation firmware files have the extension .anfw. The dialogue shows the version
number of the firmware file along with the date and time it was generated by
engineering.
12.9.3
Log Converter
This tool allows the user to convert Motus log files into various standard formats that
are readable by many programs. The position offset values can used to project the
exported position to a point other than the centre of the Motus unit. For most users
these values should be left at zero.
Illustration 52: Screenshot of Motus Manager Firmware
Update dialogue
Illustration 53: Screenshot of Motus Manager Log
Converter dialogue
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12.9.4
Network Connect
The Network Connect dialogue allows Motus Manager to make a connection to Motus
over a TCP/IP network rather than the default serial port connection. This allows Motus
to be used with ethernet to serial converters. Advanced Navigation recommends
Lantronix ethernet to serial converters.
Illustration 54: Screenshot
of Motus Manager Network
Connect dialogue
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13
OEM Integration
13.1
OEM PCB Mechanical Mounting
Motus OEM mounts to its target PCB through the use of four mounting holes on the
aluminium frame. The aluminium frame is designed to achieve effective mating height
for the board to board connector without any additional components. Once the Motus
OEM is connected to target PCB, four M1.6 screws and washers and nuts on the back
side of the target PCB are used to hold the Motus OEM in place, please see Illustration
55. The length of the M1.6 screws will be depended on the thickness of the target PCB.
M1.6x8mm screws are recommended for 1.6mm thickness target PCBs.
Illustration 55: Motus OEM exploded mounting view
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13.2
OEM Electrical Connector
The electrical connection to the Motus OEM PCB is through a Hirose DF40 series 20 pin
micro pitch board to board connector. These connectors have shock absorbing
features, a large self-alignment distance and high contact reliability. A positive click
should be felt when successful mating occurs between Motus OEM and the target
board. It should be noted that this connector is not designed for the Motus OEM to be
plugged in whilst power is applied to the user's PCB and connector mating cycles
should not exceed 50 cycles to ensure connector reliability.
The manufacturers part number for the required PCB connector is
Hirose Part #: DF40C(2.0)-20DS-0.4V(51)
The connector can be ordered from the following distributors using the following
numbers:
Digikey Part #: H11905CT-ND
Mouser Part #: 798-DF40C20DS0.4V51
Please see Illustration 58 below for the connector pin numbering.
Illustration 56: Motus OEM development board
Illustration 57: Motus OEM mounted on
development board
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Illustration 58: Motus OEM connector pin numbering
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Pin
Function
1
Supply Voltage
2
Ground
3
Supply Voltage
4
Ground
5
Supply Voltage
6
Ground
7
3.3V translator supply, see section 13.2.1
8
Ground
9
Primary UART receive
10
Reset line, see section 13.2.2
11
Primary UART transmit
12
GPIO1
13
No connection
14
GPIO2
15
No connection
16
Auxiliary UART transmit
17
No connection
18
Auxiliary UART receive
19
No connection
20
No connection
Table 19: Pin allocation table
13.2.1
Interoperability with Different Voltage Systems
All signals are 3.3 volt level, however inputs are tolerant to 5 volt signals from the
target interface. If you require a different voltage level to be compatible with your
target system it is recommended that you install a voltage level translator between
the signals of each device. To power the translator 3.3V is provided on pin 7 of the
Motus OEM connector. This supply is only capable of driving up to 25mA and should be
appropriately decoupled when powering a circuit.
13.2.2
Reset Line
The reset line is internally pulled high on Motus OEM. This pin must be left floating for
normal operation. If a user wishes to reset Motus OEM the pin can be pulled low
externally to force a reset. It is important that this signal is not driven high under any
circumstances as it will prevent the Motus OEM from functioning correctly. Please keep
the reset line track length to a minimum to avoid noise.
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13.2.3
Basic Connection
Please see Illustration 59 for the basic electrical connections required by Motus OEM.
13.3
Recommended Footprint
The footprint for Motus OEM incorporates four through-hole for M1.6 screws to pass
through and 20 SMD pads for the board to board connector. The board to board
connector should be the only component within the “keep out” area as shown in
Illustration 60 and Illustration 61.
Illustration 59: Motus OEM basic electrical connections
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PCB footprint files are provided in the documentation section of the website. Please
contact Advanced Navigation support if you have any issues or to verify your footprint
is correct.
Illustration 60: Photo of Motus OEM mounting PCB
footprint
Illustration 61: Recommended footprint for Motus OEM
35
27
4 x
1.70
8.89
6.10
A
"Keep Out" Area
0.70
0.20
0.40
3.78
DETAIL A
SCALE 2:1
1
2
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13.4
OEM Power Supply
A high level of power supply filtering has been built into Motus OEM, however it is still
recommended that the power supply be free of significant noise. The unit is only rated
for inputs from 4.5 V to 5.5 V, exceeding 6 V can cause permanent damage to the unit.
On start-up of the Motus OEM the device will initially draw an increased impulse
current (~400mA for 2 microseconds) whilst it charges on board capacitors. It is
important that the user's circuit is tolerant to these small impulses on start-up to avoid
unsuccessful power up. It is recommended that a supply is selected that can provide a
maximum current of 0.5A. Switch-mode supplies are suitable as Motus OEM has on-
board filters to remove any supply noise and ripple.
13.5
OEM Pin Protection
Users should ensure that any signals that are connected externally from the PCB,
including GPIO and UART pins, are adequately protected. The use of a 5V zener diode
and 1k resistor should provide enough protection for the majority of use cases, see
Illustration 62.
External interface pins on Motus have on board pull-up/pull-down resistors enabled to
avoid signals oscillating when not connected. The user shouldn't need to place any
pull-up or pull-down resistors on their PCB.
Illustration 62: Motus OEM external signal protection example
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14
OEM Development Board
The OEM development board is a configurable PCB that provides developers with easy
access to all of the features of the Motus OEM unit through a number of different
interfaces. Illustration 63 shows an image of the OEM development board.
Illustration 63: Motus OEM development board
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14.1
Serial UART to USB Converter
An FTDI FT232R USB to serial UART converter chip is included on board to allow the
Motus OEM to interface directly to a computer through USB. Two status LEDs indicate
the flow of data to and from the USB port.
USB drivers for all operating systems can be downloaded directly from FTDI's website
at http://www.ftdichip.com/Products/ICs/FT232R.htm.
All development boards are shipped with this interface enabled as standard.
14.2
Dual RS232 Transceiver
An Exar Corporation SP3222EU dual channel serial UART to RS232 transceiver is
included on the development board to allow developers to communicate with the
Motus OEM unit via RS232. The SP3222EU allows baud rates of up to 1000000 baud.
Channel 1 of the SP3222EU is for use with the primary serial port on the Motus OEM
unit and Channel 2 of the SP3222EU is for use with GPIO 3 (RS232 TX 2) and GPIO 4
(RS232 RX 2).
Connection to the RS232 level signals is through a 3x2 2.54mm header, see
Illustration 64. This header is on the left of the board and allows developers to attach
wires or headers as needed.
Please note that by default the SP3222EU is disabled. Switch 1 turns it on, please see
section 14.4.
14.3
GPIO Header and Status LEDs
Users have access to 4 multi-purpose GPIO pins from Motus OEM. These are available
Illustration 64: RS232 header with functions labelled
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on the 7x2 2.54mm header, see Illustration 65. Two of these pins (GPIO 1 & 2) are also
connected to LEDs on the development board. When using a GPIO in certain input
functions, the LED can cause interference with the signal. In this situation, the LED's
resistor should be removed. When using the GPIO lines for off board functions it is
important to note that these signals are not protected against static charges, over-
voltage or over-current events. Failure to protect the signals may result in damage to
Motus OEM. Other pins on the GPIO header include a regulated 3.3V supply from
Motus that can supply up to 50mA, Motus' reset line and the external voltage input
(VEXT).
14.4
Configuration Switches
The OEM development board contains a DIP switch array that allows the user to route
signals between the USB to serial converter, RS232 converter and GPIO header. The
configuration switches are shown below in Illustration 66 in their default positions. The
default position routes Motus' primary serial port to the USB to serial converter and
has GPIO 3 and GPIO 4 connected only to the GPIO header. Please see Table 20 for the
configuration switch functions.
Illustration 65: GPIO header with functions labelled
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Switch
Default
Function
1
Off
Power on RS232 transceiver.
When the RS232 transceiver is powered on GPIO 3 and 4 will be
connected to RS232 TX 2 and RS232 RX2 respectively. It will no
longer be possible to use GPIO 4 in a TTL level mode. The primary
serial port TX will also be connected to RS232 TX 1 but the primary
serial port RX will only be connected to RS232 RX 1 if switch 2 is
turned on.
2
Off
Connect primary serial port RX to RS232 transceiver (RS232 RX 1).
Please note that only one of the switches 2,3 or 4 should be turned
on at once to prevent short circuit.
3
Off
Connect primary serial port RX to USB serial converter. Please note
that only one of the switches 2,3 or 4 should be turned on at once
to prevent short circuit.
4
Off
Connect primary serial port RX to GPIO header (UART RX). Please
note that only one of the switches 2,3 or 4 should be turned on at
once to prevent short circuit.
Table 20: Configuration switch functions
14.4.1
Primary Serial Port to USB
Illustration 66: Configuration
switches in their default
position
Illustration 67: Switch positions
for primary serial port to USB
(default)
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14.4.2
Primary Serial Port to RS232 1 and GPIO 3 & 4 to RS232 2
14.4.3
Primary Serial Port and GPIO 3 & 4 to GPIO Header at TTL levels
Illustration 69: Switch
positions for primary serial
port and GPIO 3 & 4 to GPIO
header at TTL levels
Illustration 68: Switch positions
for primary serial port to RS232
1 and GPIO 3 & 4 to RS232 2
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14.5
Power source
The development board has two power source options; USB power (5V nominal) or an
external power source. By default, the development board is configured to use USB
power. The external power source can be fed into the board through VEXT on either
the GPIO header of RS232 header and can be any voltage between 4V and 36V. Please
refer to the Motus OEM Reference Manual for full power supply requirements. The
power source is selected by a three way switch, please see Illustration 70 and
Illustration 71.
14.6
Schematics
See the following pages for the development board schematics.
Illustration 70: Power switch position for USB
power (default)
Illustration 71: Power switch position for
external power
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15
Interfacing
15.1
Communication
Communication with Motus is over the primary RS422 or RS232 interface in the
Advanced Navigation Packet Protocol (ANPP). The RS422 or RS232 format is fixed at 1
start bit, 8 data bits, 1 stop bit and no parity. See section 16 for details on the protocol.
Model
Primary Port
Auxiliary Port
GPIO Port
Motus Rugged RS232
Yes
Yes
Yes
Motus Rugged RS422
Yes
No
Yes
Table 21: I/O ports available
The primary port is used to communicate with Motus Rugged using the ANPP format.
Any required data in ANPP packet format can be configured to output on request or at
predetermined rates.
15.1.1
Baud Rate
The default baud rate for all the ports of Motus Rugged is 115200 bps. The primary
port baud rate can be set anywhere from 2400 to 2000000 baud and can be modified
using the Motus Manager software (see section 12.8.5) or the Baud Rates packet, see
section 16.10.3. It is important to select a baud rate that is capable of carrying the
amount of data that Motus is configured to output. See Packet Rates in section 16.5 for
more details on the data output calculation. The data rate in bytes per second can be
calculated by dividing the baud rate by 10. For example, if the baud rate is 115200,
then the data rate is 11520 bytes per second.
15.2
External Data
External sources of position, velocity and/or heading can be integrated into Motus's
filter solution. The data can be sent to Motus in the ANPP format over the primary port
or through one of the GPIO pins in a number of different formats. If using the ANPP,
please use Table 22 below to find the relevant section. If using the GPIOs, please see
section 15.3.
Packet
Section
External Position and Velocity
16.9.25
External Position
16.9.26
External Velocity
16.9.27
External Body Velocity
16.9.28
External Heading
16.9.29
External Time
16.9.33
External Depth
16.9.34
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External Odometer
16.9.40
External Air Data
16.9.41
Table 22: ANPP external data reference
15.3
GPIO Pins and Auxiliary RS232
The RS232 model of Motus contains two general purpose input output (GPIO) pins and
an auxiliary RS232 port on the main connector. The RS422 model of Motus does not
have the auxiliary port. These pins and ports are multi function and can be used to
extend Motus with additional peripherals, sensors and data formats. The GPIO pins
have digital input, digital output, frequency input and frequency output functionality.
For for both models, GPIO1 can also function as an RS232 serial transmit line and
GPIO2 can function as an RS232 serial receive line. The GPIO serial baud rate can be
configured anywhere from 2400 to 250 K baud. The auxiliary serial baud rate can be
configured anywhere from 2400 to 2 M baud. Changes to these baud rates can be
made by using the Baud Rates dialog box in Motus Manager (see section 12.8.5) or the
Baud Rates Packet (see section 16.10.3).
The available GPIO pin functions and auxiliary RS232 functions are listed below in
section 15.4. The function of a GPIO pin or the auxiliary RS232 can be changed at any
time using the GPIO configuration dialog box in Motus Manager (see section 12.8.6) or
the GPIO Configuration Packet (see section 16.10.7). GPIO 1 and GPIO 2 function at 0 –
5 volt levels for digital input, digital output, frequency input and frequency output, but
when a serial data function is selected that GPIO pin automatically switches to RS232
level.
15.4
Dynamic Pin Functions
Function
Type
GPIOs
Auxiliary
RS232
Inactive
Tristate
All
All
1PPS Output
Digital Output
All
Transmit
GNSS Fix Output
Digital Output
All
Transmit
Odometer Input
Frequency Input
All
Receive
Zero Velocity Input
Digital Input
All
Receive
Pitot Tube Input
Frequency Input
All
Receive
NMEA Input
Serial Receive
2
Receive
NMEA Output
Serial Transmit
1
Transmit
Novatel GNSS Input
Serial Receive
2
Receive
Topcon GNSS Input
Serial Receive
2
Receive
ANPP Input
Serial Receive
2
Receive
ANPP Output
Serial Transmit
1
Transmit
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Function
Type
GPIOs
Auxiliary
RS232
Disable Magnetometers
Digital Input
All
Receive
Set Zero Orientation Alignment
Digital Input
All
Receive
System State Packet Trigger
Digital Input
All
Receive
Raw Sensors Packet Trigger
Digital Input
All
Receive
Pressure Depth Transducer
Frequency Input
All
Receive
Trimble GNSS Input
Serial Receive
2
Receive
u-blox GNSS Input
Serial Receive
2
Receive
Hemisphere GNSS Input
Serial Receive
2
Receive
Teledyne DVL Input
Serial Receive
2
Receive
Tritech USBL Input
Serial Receive
2
Receive
Linkquest DVL Input
Serial Receive
2
Receive
Linkquest USBL Input
Serial Receive
2
Receive
Nortek DVL Input
Serial Receive
2
Receive
Left Wheel Speed Sensor
Frequency Input
All
Receive
Right Wheel Speed Sensor
Frequency Input
All
Receive
1PPS Input
Digital Input
All
Receive
Wheel Speed Sensor
Frequency Input
All
Receive
Wheel Encoder Phase A
Frequency Input
All
Wheel Encoder Phase B
Frequency Input
All
Event 1 Input
Digital Input
All
Receive
Event 2 Input
Digital Input
All
Receive
TSS1 Output
Serial Transmit
1
Transmit
Simrad 1000 Output
Serial Transmit
1
Transmit
Simrad 3000 Output
Serial Transmit
1
Transmit
Serial Port Passthrough
Serial
All
All
Gimbal Encoder Phase A
Frequency Input
All
Gimbal Encoder Phase B
Frequency Input
All
Odometer Direction, Forward Low
Digital Input
All
Receive
Odometer Direction, Forward High
Digital Input
All
Receive
Reverse Alignment, Forward Low
Digital Input
All
Receive
Reverse Alignment, Forward High
Digital Input
All
Receive
Zero Angular Velocity Input
Digital Input
All
Receive
Table 23: GPIO pin functions
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15.4.1
1PPS Output
In this function, the pin pulses for 50 milliseconds to signal the precise second. The
1PPS line starts pulsing approximately 100 milliseconds after power up and always
fires irrespective of whether Motus has accurate time or not. It is important to note
that when Motus acquires time corrections from a GNSS receiver, the 1PPS signal may
fire at an interval of less than 1 second. This typically only occurs the first time the
GNSS receiver obtains a fix after startup. The time initialised status flag can be used to
determine whether the time and 1PPS line is accurate or not.
1PPS Source
Voltage Level
Trigger
Auxiliary
-5 V to 5 V
Falling Edge
GPIO
0 to 5 V
Rising Edge
Table 24: 1PPS Specifications
15.4.2
GNSS Fix Output
In this function, the pin is low when there is no GNSS fix or a 2D fix and high when
there is a 3D, SBAS, Differential or RTK GNSS fix.
15.4.3
Odometer Input
This function is designed for low resolution vehicle speed sensors and odometers. It
expects a normally low input with a high state for the trigger. If the pulse length is
more than 0.1 metres this odometer input function should be used, if it is less than 0.1
metres the wheel speed sensor function should be used. Please contact Advanced
Navigation support for help integrating with your speed sensor.
Parameter
Value
Trigger
Low → High
Maximum Frequency
600Khz
Maximum Pulse Rate
4294967 pulses/metre
Table 25: Odometer Specifications
15.4.4
Zero Velocity Input
When using this function, a high state indicates to Motus that it is stationary. The low
state indicates that the vehicle is not stationary. Use of this function can significantly
improve drift performance when a GNSS signal is not available.
15.4.5
Pitot Tube Input
This function is designed for fixed wing aircraft to enhance navigation through the use
of a pitot tube to measure airspeed. It requires a differential pressure sensor that has a
frequency output such as the Kavlico P992 (frequency output option) or the
Paroscientific series 5300. Please contact Advanced Navigation support for help
integrating with a pitot tube.
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15.4.6
NMEA Input
This function accepts external data in the NMEA format. Advanced Navigation
recommends against using NMEA where possible due to the inefficiency, inaccuracy
and poor error checking of the format. All NMEA messages received must have a valid
checksum. Supported messages are listed below. The recommended combination of
messages are GPGGA, GPVTG and GPZDA with optional messages GPGSV and GPGSA.
Message ID
Description
GPGGA
GNGGA
3D position
GPGLL
GNGLL
2D position
GPRMC
GNRMC
2D position, 2D velocity and coarse time
GPVTG
GNVTG
2D velocity
GPHDT
GNHDT
HEHDT
Heading
GPGSV
GNGSV
Satellites
GPGSA
GNGSA
Dilution of Position
GPZDA
GNZDA
Time
Table 26: Supported NMEA messages
15.4.7
NMEA Output
This function outputs a configurable combination of NMEA messages at up to 50 Hz.
The messages output and the output rate can be configured using the GPIO Output
configuration dialogue in Motus Manager. A complete list of available messages can be
found in section 16.10.14.
Advanced Navigation recommends against using NMEA where possible due to the
inefficiency, inaccuracy and poor error checking of the format.
$GPZDA,031644.460,07,05,2013,00,00*52
$GPGGA,031644.460,3352.3501851,S,15112.2355488,E,6,00,1.4,150.0,M,0.0,M,,*7E
$GPVTG,089.19,T,089.19,M,000.00,N,000.00,K,E*27
$GPRMC,031644.460,A,3352.3501851,S,15112.2355488,E,0.0,89.2,070513,12.5,W,E*02
$GPHDT,89.2,T*06
$PASHR,031644.460,089.19,T,-00.01,-00.47,-00.00,,,,0,0*2E
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15.4.8
Novatel GNSS Input
This function is designed for interfacing Motus with a Novatel GNSS receiver. It accepts
data in the Novatel binary format and requires messages BESTPOSB and BESTVELB at
rates higher than 1 Hz (20Hz recommended). The message BESTSATSB is optional to
display detailed satellite information. The message HEADING is also supported for
ALIGN capable receivers.
15.4.9
Topcon GNSS Input
This function is designed for interfacing Motus with a Topcon GNSS receiver. It accepts
data in the GRIL TPS binary format and expects messages PG and VG at rates higher
than 1 Hz.
15.4.10
ANPP Input
This function accepts data in the ANPP format as specified in section 16.
15.4.11
ANPP Output
This function outputs data in the ANPP format as specified in section 16. For packets to
be sent out they must be requested through another GPIO functioning as ANPP input.
15.4.12
Disable Magnetometers
This function accepts a digital input with a low state enabling the magnetometers and
a high state disabling the magnetometers.
15.4.13
Set Zero Orientation Alignment
This function accepts a digital input. The input is normally low and a transition from
low to high causes Motus to set it's alignment so that the current orientation is zero.
Due to the risk of exhausting the flash cycles, the change is not permanent and will
disappear on reset. To make it permanent the Installation Alignment Packet must be
read and then sent back to Motus with the permanent flag set. This function requires
de-bouncing if attached to a switch.
15.4.14
System State Packet Trigger
This function accepts a digital input. The input is normally low and a transition from
low to high causes Motus to send the system state packet. This function requires de-
bouncing if attached to a switch.
15.4.15
Raw Sensors Packet Trigger
This function accepts a digital input. The input is normally low and a transition from
low to high causes Motus to send the raw sensors packet. This function requires de-
bouncing if attached to a switch.
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15.4.16
Pressure Depth Transducer
This function is designed for interfacing with a legacy pressure depth transducer.
These are no longer available and the function is now deprecated.
15.4.17
Trimble GNSS Input
This function is designed for interfacing Motus with an external Trimble GNSS receiver.
It accepts data in the Trimble binary format GSOF and expects packet 0x40 with
records 1, 2, 8, and 12 at rates higher than 1Hz (20Hz recommended) and optional
records 9 and 34 at 1 to 2Hz.
15.4.18
u-blox GNSS Input
This function is designed for interfacing Motus with a u-blox GNSS receiver. It accepts
data in the u-blox binary format and expects message NAV-PVT or NAV-SOL at rates
higher than 1Hz.
15.4.19
Hemisphere GNSS Input
This function is designed for interfacing Motus with a Hemisphere GNSS receiver. It
accepts data in the Hemisphere binary format and expects message Bin1 at rates
higher than 1Hz. For Hemisphere receivers that provide heading using two antennas,
NMEA should be used instead as the binary format does not allow for transmission of
heading information.
15.4.20
Teledyne DVL Input
This function accepts DVL data from a Teledyne DVL. For assistance with configuration
please contact [email protected].
15.4.21
Tritech USBL Input
This function accepts USBL data from a Tritech USBL. For assistance with configuration
please contact [email protected].
15.4.22
Linkquest DVL Input
This function accepts DVL data from a Linkquest DVL. For assistance with
configuration please contact [email protected].
15.4.23
Linkquest USBL Input
This function accepts USBL data from a Linkquest USBL. For assistance with
configuration please contact [email protected].
15.4.24
Nortek DVL Input
This function accepts DVL data in the Nortek DVL binary format. It accepts the packets
0x1B (DVL Bottom Track) and 0x1D (DVL Water Track). The recommended update rate
is 8Hz.
Motus Reference Manual
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Version 1.1
29/11/2019
15.4.25
Left Wheel Speed Sensor
This function is designed for the left wheel of a vehicle with dual wheel speed sensors.
15.4.26
Right Wheel Speed Sensor
This function is designed for the right wheel of a vehicle with dual wheel speed
sensors.
15.4.27
1PPS Input
This function is designed to allow external GNSS receivers to synchronise time with
Motus. It triggers on a transition from low to high.
15.4.28
Wheel Speed Sensor
This function is designed for high resolution vehicle speed sensors and wheel speed
sensors. It expects a normally low input with a high state for the trigger. If the pulse
length is more than 0.1 metres the odometer input function should be used, if it is less
than 0.1 metres this wheel speed sensor function should be used. Please contact
Advanced Navigation support for help integrating with your speed sensor.
Parameter
Value
Trigger
Low → High
Maximum Frequency
40 MHz
Maximum Pulse Rate
4,294,967,295 pulses/metre
Table 27: Wheel Speed Sensor Specifications
15.4.29
Wheel Encoder Phase A
This function is designed for rotary incremental quadrature encoders. It should be
used in combination with Wheel Encoder Phase B.
15.4.30
Wheel Encoder Phase B
This function is designed for rotary incremental quadrature encoders. It should be
used in combination with Wheel Encoder Phase A.
15.4.31
Event 1 Input
This function is designed to allow external events to be recorded inside Motus's
output. The event is recorded in the filter status, see section 16.9.1.2, and resets after
the next packet is output. The event triggers on a transition from low to high.
15.4.32
Event 2 Input
This function is designed to allow external events to be recorded inside Motus's
output. The event is recorded in the filter status, see section 16.9.1.2, and resets after
the next packet is output. The event triggers on a transition from low to high.
Motus Reference Manual
Page 99 of 146
Version 1.1
29/11/2019
15.4.33
TSS1 Output
This function outputs the TSS1 format at a user configurable rate up to 50 Hz. The
output rate can be configured using the GPIO Output configuration dialogue in Motus
Manager, see section 12.8.10.
15.4.34
Simrad 1000 Output
This function outputs the Simrad 1000 format at a user configurable rate up to 50 Hz.
The output rate can be configured using the GPIO Output configuration dialogue in
Motus Manager, see section 12.8.10.
15.4.35
Simrad 3000 Output
This function outputs the Simrad 3000 format at a user configurable rate up to 50 Hz.
The output rate can be configured using the GPIO Output configuration dialogue in
Motus Manager, see section 12.8.10.
15.4.36
Serial Port Passthrough
This function allows passthrough communication through either GPIO 1 and 2 or the
Auxiliary RS232. To transmit data use the Serial Port Pass-through Packet. When data
is received it will be sent back using the same Serial Port Pass-through Packet.
15.4.37
Gimbal Encoder Phase A
This function is designed for interfacing with a rotary incremental quadrature encoder
to measure the azimuth angle of a gimbal that Motus is installed in. It should be used
in combination with Gimbal Encoder Phase B.
15.4.38
Gimbal Encoder Phase B
This function is designed for interfacing with a rotary incremental quadrature encoder
to measure the azimuth angle of a gimbal that Motus is installed in. It should be used
in combination with Gimbal Encoder Phase A.
15.4.39
Odometer Direction, Forward Low
This function is designed to take a reversing indication input for direction with an
odometer or wheel encoder. It should be used in combination with Odometer Input or
Wheel Speed Sensor.
15.4.40
Odometer Direction, Forward High
This function is designed to take a reversing indication input for direction with an
odometer or wheel encoder. It should be used in combination with Odometer Input or
Wheel Speed Sensor.
15.4.41
Reverse Alignment, Forward Low
This function is designed to reverse the alignment settings for vehicles that can have
