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For details about the overall configuration of the RTK-GPS system refer to this section.

GNSS Output Format

JSON

Code Block
"gnssData": {
    "altitude": 0.0,
    "hdop": 0.0,
    "heading": 0,
    "latitude": 0.0,
    "longitude": 0.0,
    "height": 0.0,
    "nSat": 0,
    "orientation": {
        "w": 1.0,
        "x": 0.0,
        "y": 0.0,
        "z": 0.0
    },
    "quality": 0,
    "sensorName": "",
    "timestamp": 0,
    "tmg": 0.0,
    "undulation": 0.0
}

Protobuf

Code Block
message GnssData {
    int64 timestamp = 1;
    double latitude = 3;
    double longitude = 4;
    double period = 5;
    int32 frame_count = 6;
    double latency = 8;
    string sensor_name = 11;
    Quaternion orientation = 12;
    double height = 13;
    double vertical_accuracy = 14;
    double horizontal_accuracy = 15;
    int32 quality = 16;
    int32 n_sat = 17;
    double hdop = 18;
    double tmg = 19;
    double heading = 20;
    double altitude = 21;
    double undulation = 22;
}

Important Output Data

Parameter name

Description

Unit

timestamp

Timestamp of current GNSS data

nanoseconds (in case GPS time is used as clock this is the duration since start of the day in UTC time)

longitude

Longitude part of GPS position

degree

latitude

Latitude part of GPS position

degree

height

The height of the receiver above the earth surface reference ellipsoid

m

quality

Quality of the GPS signal:

0: Fix not valid
1: GPS fix
2: Differential GPS fix
3: Not applicable
4: RTK fixed
5: RTK float
6: INS Dead reckoning

n/a (comment: for RTK enabled systems RTK fix provides the highest cm accuracy. If this quality can’t be reached, the number of visible satellites or connection to base station might be an issue.)

Odometry

The vehicle source is the data source that reads raw CAN data messages from a given CAN bus interface and parses the vehicle data using to the provided CAN protocol.

...

Configuration example
Code Block
    "vehicle": {
      	"type": "Automotive",
      	"vehicleStateEndpoint": "tcp://*:8999",
      	"settings": {
        		"canInterface": "Internal",
        		"canEndpoint": "tcp://localhost:9921",        
        		"vehicleType": "Minimal",
        		"canProtocol": {
          			"velocityCanId": 209,
          			"velocityScale": 0.015625012,
          			"endianness": "little",
          			"velocityBitsLength": 16,
          			"velocityStartBit": 0
        }
      }
   		}
	}
}

Vehicle Parsing with Separate Wheel Velocities
Anchor
Vehicle-Parsing-with-Separate-Wheel-Velocities
Vehicle-Parsing-with-Separate-Wheel-Velocities

...

Configuration example
Code Block
    "vehicle": {
      	"type": "Automotive",
      	"vehicleStateEndpoint": "tcp://*:8999",
      	"settings": {
        		"canInterface": "PeakCAN",
        		"canEndpoint": "tcp://localhost:9921",
        		"vehicleType": "External",
        		"wheelBase": 2.750,
        		"trackWidth": 1.595,
        		"canProtocol": {
          			"velocityCanId": 212,
          			"velocityScale": 0.015625012,
          			"endianness": "little",
          			"velocityStartBits": {
            "FrontLeftWheel": 0,
            				"FrontLeftWheel": 0,
				"FrontRightWheel": 16,
            				"RearLeftWheel": 32,
            				"RearRightWheel": 48
          			}  
        }
      }
    		}
	}
}

Additional Parameters

Gear Stick Position for Velocity Sign

...

Configuration template
"vehicle": { ... "settings": { ... "vehicleType": "External", ... "canProtocol
Code Block
"vehicle": {
...
	"settings": {
        	...       
   },
          		"vehicleType": "External",
		"canProtocol": {
			"gearCanId": 1,
          			"gearStartBit": 2,
          			"gearBitslength": 3,
          			"gearReverseValue": 4 
        }
      }
   		}
	}
}

Steering information for Ackermann model

...

The steeringTable configuration block would look something like below.

Code Block
    "vehicle": {
    ...
      	"settings": {
      	...       
        		"vehicleType": "ExternalWithSteering",
        ...
        		"canProtocol": {
        			...
          		},
        		
		"steeringTable": {
            			"steeringWheelAngles": [
            			  -360, -340, -320, -300,
            			  ...
			              300, 320, 340, 360],
		          "wheelAngleType": "Right",
       		   "wheelAngles": [
            			-30.0, -25.5, -20.0, -15.0,
            			...
            			19.0, 26.0, 35.5, 40.0 ]
        }
        }
      }
   		}
	}
}

Predefined Vehicle Parsing

...

See a technical description of FusionHub’s communication interface in one of the following chapters.

JSON

Code Block
{
    "fusedVehiclePose": {
        "acceleration": {
            "x": 0.0,
            "y": 0.0,
            "z": 0.0
        },
        "globalPosition": {
            "x": 0.0,
            "y": 0.0
        },
        "lastDataTime": {
            "timestamp": 0
        },
        "position": {
            "x": 0,
            "y": 0
        },
        "timestamp": {
            "timestamp": 0
        },
        "utmZone": "31T",
        "yaw": 0
      }
}

Protobuf

Code Block
syntax = "proto3";

package Fusion.proto;

message Vector2 {
    double x = 2;
    double y = 3;
}

message Vector {
    double x = 2;
    double y = 3;
    double z = 4;
}

message FusedVehiclePose {
    int64 timestamp = 1;
    Vector2 position = 2;
    Vector2 global_position = 3;
    double yaw = 4;
    string utm_zone = 5;
    int64 timecode = 6; // Optional: if 0 not set.    
    Vector acceleration = 7;
}

message StreamData {
    int32 sequence_number = 1;
    FusedVehiclePose fused_vehicle_pose = 9;
}

...

The high dynamics filter works well for scenarios with agressive driving maneuvers such as drifting and cornering. During such maneuvers the turning motion of the wheels generally doesn’t directly correspond with the direction of the vehicle. Therefore for this filter doesn’t rely on wheel velocity measurements for localization like the low-dynamics (LD) filter. This filter uses information from the wheels to determine if the car has come to a full stop.

...

  • fusedVehiclePose (2D pose): Output equivalent to the LD filter output. Includes position in meters relative to starting point, global position (lon, lat) and heading.

  • fusedPose (3D pose): relative to starting point, x, y (in meters) + z (height in meters) + 3D orientation quaternion

  • globalFusedPose: globally referenced 3D position (longitude, latitude, height in meters) + 3D orientation quaternion in ENU frame

...

You can find more information regarding the ENU coordinate system here.

Notes on IMU Arrangement

The used For the car frame is we use the Volkswagen (VW) coordinate frame convention:

...

And the orientation quaternion woud be [w, x, y, z, w] = [ 0, 0, 0, 1 , 0 ] which can be specified in the configuration like below:

Code Block
"imuToCarRotation": {
    "w": 0,
    "x": 0,
    "y": 0,
    "z": 1
}  

Check this page for more information on how to calculate the orientation quaternion.

Note: The orientation of the IMU for a unity quaternion [ 1, 0, 0, 0 ] would be

Code Block
IMU mounting
x: backwards
y: right
z: up

Configuration Block

Insert the following configuration block into your config.json file in the sinks section to activate the HD filter. The filter's node name is gnssImuFusion.

..
Code Block
..
  "sinks": {
    ..,
    "gnssImuFusion": {
        "echoFusedPose": false,
        "endpoint": "tcp://*:8803",
        "sinksfuser": {
     ..,       "gnssImuFusionfitModel": {"ModelGnssImu",
            "echoFusedPoseaccelError": false,0.01,
            "endpointomegaError": "tcp://*:8803"0.02,
            "measurementError": 0.05,
            "fuserimuToCarRotation": {
                "fitModelw": 1,
 "ModelGnssImu",               "x": 0,
                "accelErrory": 0.01,
,
                "z": 0
           "omegaError": 0.02 },
            "measurementErroroutputWhenFilterNotReady": 0.05false,
            "imuToCarRotationretainStateWhenStopped": {
   true,
            "wsmoothFit": 1true,
   
            "xglobalOrigin": 0,{
                "ylongitude": 0139.73226516666668,
                "zlatitude": 035.657632
            }
        }
    }
..

See below a description of the parameter options for the HD filter.

Parameter name

Description

Default

echoFusedPose

fusedVehiclePose output is printed to command line

false

endpoint

Output port for the fusion result

8801

fitModel

Model to use for fusion.

ModelGnssImu

accelError

Acceleration error for Kalman filter. Keep default value.

0.01

omegaError

Omega error for Kalman filter. Keep default value.

0.02

measurementError

Measurement error for Kalman filter. Keep default value.

0.05

imuToCarRotation

Orientation quaternion of IMU relative to car frame

1, 0, 0, 0

smoothFit

Enable this option to prevent filter output from jumping between IMU data and GPS measurement. Keep enabled.

true

singleEndpoint

  • If enabled, the different fusion output messages will be published to the same port "endpoint"

  • If disabled, the "endpoint" parameter above, is the output port for the FusedVehiclePose msg type only.

true

poseEndpoint

Output port for the FusedPose msg type.

8804 if singleEndpoint=false

globalPoseEndpoint

Output port for the GlobalFusedPose msg type.

8805 if singleEndpoint=false

outputRawGnssData

Publishes raw Gnss data position instead of the fusion output. Useful for debugging.

false

outputWhenFilterNotReady

Publishes a temporary raw Gnss data output while the filter is initializing. Useful for a minimal sanity check before moving the vehicle.

false

retainStateWhenStopped

If the vehicle is detected to be stationary by looking at data from CAN bus, then the current filter state (position, rotation etc.) will be automatically retained until motion is detected.

true

globalOrigin

A global position as longitude and latitude: For fusedPose output this will be the starting point. All position outputs will be relative to this point.

{ 0, 0 }

Output Data Format

FusedVehiclePose

JSON
Code Block
{
    "fusedVehiclePose": {
        "acceleration": {
            "x": 0.0,
            "y": 0.0,
            "z": 0.0
        },
        "globalPosition": {
            "x": 0.0,
            "y": 0.0
        },
        "lastDataTime": {
            "timestamp": 0
        },
        "position": {
            "x": 0.0,
            "y": 0.0
        },
        "timestamp": {
            "timestamp": 0
        },
        "utmZone": "31T",
        "yaw": 0.0
    }
}
Protobuf
Code Block
syntax = "proto3";

package Fusion.proto;

message Vector2 {
  double x = 2;
  double y = 3;
}

message Vector {
  double x = 2;
  double y = 3;
  double z = 4;
}

message FusedVehiclePose {
  int64 timestamp = 1;
  Vector2 position = 2;
  Vector2 global_position = 3;
  double yaw = 4;
  string utm_zone = 5;
  int64 timecode = 6; // Optional: if 0 not set.
  Vector acceleration = 7;
}

message StreamData {
  int32 sequence_number = 1;
  FusedVehiclePose fused_vehicle_pose = 9;
}

Parameter name

Description

Unit

acceleration

3D acceleration vector as measured by IMU. Describes the orientation of the vehicle.

m/s^2

globalPosition

Longitude and latitude in degrees

degrees

lastDataTime

Unused

s

position

Position within UTM zone

m

timestamp

Timestamp of data acquisition

ns

utmZone

UTM zone

UTM string

yaw

Globally referenced yaw angle

rad

FusedPose

JSON
Code Block
{
	"fusedPose": {
		"lastDataTime": {
			"timestamp": 0
		},
		"orientation": {
			"w": 1.0,
			"x": 0.0,
			"y": 0.0,
			"z": 0.0
		},
		"position": {
			"x": 0.0,
			"y": 0.0,
			"z": 0.0
		},
		"timestamp": {
			"timestamp": 0
		}
    }
}
Protobuf
Code Block
syntax = "proto3";

package Fusion.proto;

message Quaternion {
  double w = 1;
  double x = 2;
  double y = 3;
  double z = 4;
}

message Vector {
  double x = 2;
  double y = 3;
  double z = 4;
}

message FusedPose {
  int64 timestamp = 1;
  Vector position = 2;
  Quaternion orientation = 3;
  Vector angular_velocity = 4;
  int64 timecode = 5; // Optional: if 0 not set.  
}

message StreamData {
  int32 sequence_number = 1;
  FusedPose fused_pose = 4;
}

Parameter name

Description

Unit

lastDataTime

Unused

s

orientation

Orientation quaternion in ENU coordinate frame

without unit

position

X, y position + height

m

timestamp

Time of data acqusition

ns

GlobalFusedPose

JSON
Code Block
{
    "globalFusedPose" {
        "orientation": {
			"w": 1.0,
			"x": 0.0,
			"y": 0.0,
			"z": 0.0
		},
        "timestamp": {
			"timestamp": 0
		},
        "position": {
            "longitude": 0.0,
            "latitude": 0.0,
            "height": 0.0
		}
	}
}
Protobuf
Code Block
syntax = "proto3";

package Fusion.proto;

message Quaternion {
  double w = 1;
  double x = 2;
  double y = 3;
  double z = 4;
}

message GpsPoint {
  double longitude = 2;
  double latitude = 3;
  double height = 4;
}

message GlobalFusedPose {
  int64 timecode = 5; // Optional: if 0 not set.
  int64 timestamp = 1;
  GpsPoint position = 2;
  Quaternion orientation = 3;
}

message StreamData {
  int32 sequence_number = 1;
  GlobalFusedPose global_fused_pose = 10;
}

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