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| Code Block |
|---|
"type": "Optitrack",
"settings": {
"hostserverAddress": "localhost",
"connectionType": "Multicast",
"bodyID": 444
} |
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Parameter name | Description | Unit |
|---|---|---|
acceleration | 3D acceleration vector as measured by IMU. Describes the orientation of the vehicle in the vehicle coordinate system. | m/s^2 |
globalPosition | Longitude and latitude in degrees | degrees |
lastDataTime | Unused | s |
position | Position relative to starting point with X pointing North and Y pointing East in the current UTM frame | m |
timestamp | Timestamp of data acquisition | ns |
utmZone | UTM zone | UTM string |
yaw | Globally referenced yaw angle | rad |
Note: Additional Notes
The FusedVehiclePose contains a 3D acceleration vector. The acceleration is defined in the following manner: There's a configuration flag imuToCarRotation which takes a quaternion used to rotate vectors in the IMU frame to the car frame. By default it is the identity quaternion. For the LD model, the measured IMU acceleration is simply rotated by the imuToCarRotation and written to the output.
In the LD filter, pitch and roll has to be derived from the acceleration data based on a model of the stiffness of the chassis. That assumes a flat surface. The HD model offers the full 6-DOF, and we are planning to unify them to have all data available at all times.
As the filter relies heavily on GPS measurements it doesn’t deliver good results indoors. The better GPS reception, the better the resulting output of the filter. The yaw angle of the vehicle is calculated based on several GPS and odometry measurements when the car is moving. Therefore, after starting FusionHub, while the car is static, the filter will not deliver a correct yaw angle. The angle will be adjusted to the correct direction after a few seconds of driving the vehicle.
Example Configuration
Playback and fusion of prerecorded data: gpsImuFusionPlayback.json
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