README

off_highway_premium_radar_sample

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

Further information on the Bosch Radar Off-Highway Premium Sample, it’s inputs, outputs and how they can be interpreted can be found in the corresponding Technical Customer Information (TCI), which is provided with the sensor hardware.

The driver is only tested for sensor unicast configuration for varying sensor IPs and destination ports on the host.

Supported devices

Device name

Part Number

Description

Radar Off-Highway Premium Sample

- F 037 B01 061-01

- Radar sensor with up to 1024 locations

Further information: Story page for the Radar OHW Premium

Contact: off-highway.beg@bosch.com

Nodes

Driver

The radar driver opens an 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:

Sensor Driver Architecture

The signal values in a received PDU are checked for their value range and replaced by their corresponding signal-not-available (SNA) value if out of range (if applicable).

The split location data PDUs per measurement are assembled by the driver as single location data measurement and published as 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 out-of-order packet). 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 zero number of contained locations are measured. In addition, only locations are contained in the drivers 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 on /diagnostics the current status. 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 that the driver can communicate to 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 disadvantage is that each driver socket will not be able to receive, process and publish sensor broadcast messages.

The driver node is written as 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_sample_msgs/EgoVehicleData)

    • Optional, subscription is deactivated per 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 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: ~66 ms

    • Contains location measurement of 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

      • elevation_angle (LocData_EleAng_i_j): Elevation angle

      • 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 radial distance measured

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

      • azimuth_angle_variance (LocData_VarAzi_i_j): Variance of azimuth angle measured

      • elevation_angle_variance (LocData_VarEle_i_j): Variance of elevation angle measured

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

      • 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 for azimuth angle

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

      • measurement_status (LocData_MeasStat_i_j): Measurement status

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

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

  • ~/locations_header (off_highway_premium_radar_sample_msgs/msg/LocationHeader)

    • Cycle time: ~66 ms (aligned to locations)

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

  • ~/sensor_feedback (off_highway_premium_radar_sample_msgs/msg/SensorFeedback)

    • Cycle time: 50 ms

    • Loopbacks input data as feedback like ego vehicle data, time or measurement synchronization.

  • ~/sensor_state_information (off_highway_premium_radar_sample_msgs/msg/SensorStateInformation)

    • Cycle time: 10 ms

    • Contains sensor state and software version information.

  • ~/sensor_broadcast (off_highway_premium_radar_sample_msgs/msg/SensorBroadcast)

    • Cycle time: 1000 ms

    • Contains sensor ethernet configuration like IP, ports and DoIP information.

    • Only received / published if connect_sensor parameter is not set

  • ~/location_attributes (off_highway_premium_radar_sample_msgs/msg/LocationAttributes)

    • Cycle time: 66 ms (aligned to locations)

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

  • ~/sensor_dtc_information (off_highway_premium_radar_sample_msgs/msg/SensorDtcInformation)

    • Cycle time: 66 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
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 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 frames. See the FOSS documentation for further information.