Coordinate Frames

PolySync Core sensor nodes can be configured to specify the active coordinate frame through the use of parameters. All PolySync provided dynamic driver interfaces support this parameter through the Transform API.

Setting the active coordinate frame

Parameter ID 800 is the Active Coordinate Frame Identifier─which correlates to the values below─and is found in the SDF Configurator Node Configuration section.

PolySync Core provides some commonly used coordinate frame systems used in autonomous vehicles, and custom coordinate frames can be defined for use in a node.

0. Invalid

This coordinate frame should not be trusted or referenced.

1. Unknown

The originating node is unable to determine the coordinate frame identifier.

2. Not available

Coordinate frame not available. This is typically used for nodes that don’t have, or don’t need, a coordinate frame.

3. Local (sensor)

Standard right-handed local coordinate frame, also known as the vehicle coordinate frame.

4. Platform

Standard right-handed platform coordinate frame. Fixed in the platform body, i.e. a fixed body coordinate system. This is the default configuration for dynamic driver interfaces.

A PolySync Core vehicle’s coordinates conform to ISO8855:1991 and SAE J670:JAN2008, and follow the conventions shown below. Axis and angle of rotation are right handed.

For the Vehicle Centered Reference Coordinate Frame (VCRF), the origin is the center of the rear axle on the ground.

5. Relative

Standard right-handed relative coordinate frame. Typically based on a dead-reckoned navigation solution.

6. Absolute

Standard right-handed absolute coordinate frame. Typically based on an absolute or world navigation solution like the WGS84 UTM coordinate frame in a given zone.