off_highway_premium_radar

The off_highway_premium_radar package

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README

off_highway_premium_radar

:warning: The Radar Off-Highway Premium is not available yet. The content in the off_highway_premium_radar packages is preliminary and subject to change.

:information_source: The off_highway_premium_radar packages are for the Series version of the Radar Off-Highway Premium sensor. For the Sample version, go to off_highway_premium_radar_sample.

The off_highway_premium_radar package provides a driver node to receive and send UDP datagrams from / to the Bosch Radar Off-Highway Premium via a ROS interface.

Further information on the Bosch Radar Off-Highway Premium can be found here.

Supported devices

Device name	Part Number	Description
Radar Off-Highway Premium	- F037.000.158	- Radar sensor with up to 1024 locations

Contact: off-highway.beg@bosch.com

Nodes

Driver

The radar driver opens a UDP socket, decodes all UDP protocol data units (PDUs) from the radar and publishes its data as ROS messages. Moreover, it can send all required input for the radar as UDP PDUs. See the following figure for an overview:

The split location data PDUs per measurement are assembled by the driver as a single location data measurement and published as a single ROS point cloud message. There is no built-in recovery in the driver for out-of-order or dropped UDP packets for such a sequence of packets. A warning will log such cases which result in a drop of the location measurement (and eventually the following one if packets are out-of-order). Such cases will also result in a publishing frequency drop for the output message which is detected in the built-in ROS diagnosis. Reducing the load on the sensor network and receiving device will minimize the risk of such cases.

A location data measurement may contain zero locations if the ‘data measured’ flag is not set, or if no locations are actually measured. Only locations are contained in the driver’s output which have the first bit of their measurement status set (measured and range check passed).

Each cyclic output topic of the driver is monitored via ROS topic diagnostics, which checks its frequency and timestamp and publishes the current status on /diagnostics. As soon as the driver is not receiving UDP packets with the expected frequency (see UDP interface documentation) or not updated timestamps, the corresponding topic diagnostics will produce an error.

In order for the driver to communicate with the sensor, one needs to configure the connection via the network parameters. The host IP, port and sensor IP, port need to be set to the settings configured in the sensor. The defaults are stated in the UDP interface documentation and in the parameters.

One can connect the used socket via the connect_sensor parameter to already filter for UDP packets from the sensor before the driver process receives them. This has the main benefit of being able to run multiple driver processes for different sensors in parallel for the same host port (established-over-unconnected technique).

The driver node is written as a library in a modular fashion so that one can extend its functionality with custom converter classes. See design for an overview.

Subscribed topics

• ~/ego_vehicle_data (off_highway_premium_radar_msgs/EgoVehicleData)

  • Optional, subscription is deactivated by default. Can be activated via send_ego_vehicle_data ROS parameter.

  • Expected cycle time: 10 ms

  • Contains current velocity with covariance and acceleration. Only forward speed, forward speed variance, forward acceleration and yaw rate are used by the driver / sensor.

  • Uses SI units, so yaw rate is in [rad/s], will be converted by the driver into [deg/s] of UDP interface specification!

  • Is converted and sent to the sensor as UDP PDU.

  • Logs error if not all bytes of UDP PDU were sent.

Published topics

• ~/locations (sensor_msgs/msg/PointCloud2)

  • Cycle time: 70 ms +/- 20 ms

  • Contains location measurements of the radar as point cloud. Fields (all float for PCL filter compatibility, mapped Technical Customer Information signal name is specified in brackets):

    • x, y, z: Position of location

    • radial_distance (LocData_RadDist_i_j): Radial distance

    • radial_velocity (LocData_RadRelVel_i_j): Radial relative velocity

    • azimuth_angle (LocData_AziAng_i_j): Azimuth angle in cone coordinates

    • elevation_angle (LocData_EleAng_i_j): Elevation angle in cone coordinates

    • radar_cross_section (LocData_Rcs_i_j): Radar Cross Section

    • signal_noise_ratio (LocData_Snr_i_j): Strength of the received power

    • radial_distance_variance (LocData_RadDistVar_i_j): Variance of measured radial distance

    • radial_velocity_variance (LocData_RadRelVelVar_i_j): Variance of measured radial relative velocity

    • azimuth_angle_variance (LocData_VarAzi_i_j): Variance of measured azimuth angle

    • elevation_angle_variance (LocData_VarEle_i_j): Variance of measured elevation angle

    • radial_distance_velocity_covariance (LocData_DistVelCov_i_j): Covariance of measured radial distance and velocity

    • velocity_resolution_processing_probability (LocData_ProVelRes_i_j): Probability of velocity resolution processing

    • azimuth_angle_probability (LocData_ProAziAng_i_j): Probability for correct signal model of azimuth angle

    • elevation_angle_probability (LocData_ProEleAng_i_j): Probability for correct signal model of elevation angle

    • measurement_status (LocData_MeasStat_i_j): Measurement status

    • idx_azimuth_ambiguity_peer (LocData_IdAngAmb_i_j): Index for location peer of angle ambiguity

    Note: See the Technical Customer Information for further information about all fields!

• ~/locations_header (off_highway_premium_radar_msgs/msg/LocationHeader)

  • Cycle time: 70 ms +/- 20 ms (aligned to locations)

  • Contains header of location measurement including start time of measurement, operation mode and block counter.

• ~/sensor_state_information (off_highway_premium_radar_msgs/msg/SensorStateInformation)

  • Cycle time: 10 ms

  • Contains sensor state.

• ~/location_attributes (off_highway_premium_radar_msgs/msg/LocationAttributes)

  • Cycle time: 70 ms +/- 20 ms (aligned to locations)

  • Contains location measurement attributes like separabilities and precisions or interference indicators.

• /diagnostics (diagnostic_msgs/msg/DiagnosticArray)

  • Frequency: 1 Hz

  • Diagnostic status contains statuses for all published and subscribed topics.

Services

• ~/set_measurement_program (off_highway_premium_radar_msgs/srv/MeasurementProgram)

  • Set the measurement program (via ID) of the radar by sending a SetMeasurementProgram UDP PDU. Returns success if full UDP PDU was sent, false otherwise.

Parameters

See driver.yaml.

Launch files

• driver_launch.py: Starts the driver with the given parameters.

  • Arguments:

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

Free and Open Source Software (FOSS)

This library uses a modified UdpSocket class from the udp_driver class to send and receive UDP packets. See the FOSS documentation for further information.