README

off_highway_radar

The off_highway_radar package provides a receiver node to receive and decode CAN frames of the Bosch Radar Off-Highway into ROS messages - it implements an off_highway_can::Receiver. Furthermore, the package provides a sender node to encode and send needed radar input data as CAN frames - an implementation of an off_highway_can::Sender.

Further information on the Bosch Radar Off-Highway, it’s inputs, outputs and how they can be interpreted can be found in the corresponding Technical Customer Documentation (TCD) of the sensor system.

Supported devices

Device name	Part Number	Description
Radar Off-Highway	- F037.000.127 (series - from software version F037SW0157V06.0001 ) - F037.B00.575-04 (sample - from software version F037SW0116V05.0004)	- Radar sensor with up to 40 objects (filtered & unfiltered) - Object output on automotive CAN is supported

Further information: Radar systems for off-highway applications

Contact: off-highway.beg@bosch.com

Nodes

Receiver

The radar receiver decodes CAN frames into an object list, manages the current list and publishes it cyclically.

All received messages are checked for their cyclic redundancy check (CRC), rolling message counter and age (message not older than parameter allowed_age). If any of these checks do not succeed the received message is not further processed and skipped.

The relevant radar CAN frame IDs to process are specified by the object_base_id and info_id parameters. They should correspond to the first object frame ID and the info frame ID of the radar CAN node and need to be adapted for the specific bus setup. If multiple radar sensors need to be decoded on the same bus just launch multiple receiver nodes with individual *_id parameters.

The object list is published as a list of radar objects or as a point cloud and contains up to 40 objects (sensor limit). Only valid objects in the list are published (valid flag set).

The radar zone data is not processed in this version.

If the receiver node does not receive anything within a configured period (parameter timeout), it will publish a diagnostic error on /diagnostics. Also, the sensor information CAN frame gets published and is checked for the diagnostic status of the radar. On error, the node will publish a diagnostic error on /diagnostics.

Subscribed Topics

• from_can_bus (can_msgs/Frame)

  • Radar CAN frames to decode

Published Topics

• objects (off_highway_radar_msgs/Objects)

  • Update Rate: configurable with publish_frequency

  • Contains current object list of radar as custom message containing the same information as each object’s CAN frame. Mapping to the respective CAN frame is done via the id field.

• objects_pcl (sensor_msgs/PointCloud2)

  • Update Rate: configurable with publish_frequency

  • Contains current object list of radar as point cloud.

• info (off_highway_radar_msgs/Information)

  • Update Rate: On each sensor information CAN frame

  • Contains current sensor information message containing the same information as the respective CAN frame.

• /diagnostics (diagnostic_msgs/DiagnosticArray)

  • Update Rate: On each sensor information CAN frame or if receiver timed out periodically with timeout period

  • Diagnostic status contains statuses from the latest received sensor information and timeout status.

Parameters

See receiver_params.yaml.

Sender

The radar sender listens for ROS twist messages as input, encodes them as CAN frames and publishes those as ROS messages.

Both radar input CAN signals only have a limited range:

• Ego velocity signal: [-81.92 m/s, 81.9175 m/s]

• Yaw rate signal: [-163.84 deg/s, 163.83 deg/s]

Input ROS messages with values outside of these ranges are discarded by the sender and not encoded / published. Furthermore, if the ROS twist message is too old (parameter allowed_age), it is discarded, too.

The relevant radar CAN frame IDs to publish the forward velocity and yaw rate are specified by the ego_velocity_id and yaw_rate_id parameters. These parameters need to correspond to the ego velocity and yaw rate CAN frame ID for the specific bus setup. If multiple radar systems are connected to the same bus, a single radar sender is sufficient as long as these radar systems expect the ego velocity and yaw rate CAN messages on the same IDs (in contrast to multiple receivers).

If the sender node does not receive anything valid within a configured period (parameter timeout), it will publish a diagnostic error on /diagnostics.

Subscribed Topics

• velocity (geometry_msgs/TwistStamped)

  • Forward velocity and yaw rate is sent to the radar for compensating velocity readings

Published Topics

• to_can_bus (can_msgs/Frame)

  • Encoded radar CAN frames

• /diagnostics (diagnostic_msgs/DiagnosticArray)

  • Update Rate: 1 Hz or if sender timed out periodically with timeout period

  • Diagnostic status only contains timeout status

Parameters

See sender_params.yaml.

Launch files

• receiver_launch: Starts the receiver with the given parameters.

  • Arguments:

    • params: Path to ROS YAML parameter file to load for receiver. If not provided, default parameters from this package are loaded.

• sender_launch: Starts the sender with the given parameters.

  • Arguments:

    • params: Path to ROS YAML parameter file to load for sender. If not provided, default parameters from this package are loaded.