All sensors of the UMRR platform are prepared for operation in a network. For automotive applications, the individual Radar device's communication is in most cases implemented via CAN or FlexRay bus.

Up to eight UMRR sensors can be connected to one CAN bus. The devices are identified by a "sensor ID" ID0-ID7. If a CAN communication is established, the bus is conflict-free arbitrated using a proprietary time triggered CAN protocol. This allows a very efficient exploitation of the limited CAN bandwidth.

For single sensors, a free-running mode and various synchronized modes (using an external synchronization command) are available. Multi-sensor setups can also be either internally or externally synchronized. For an optimum operation, not only the communication procedure, but also start and end time of a measurement cycle as well as Radar transmit waveform parameters can be externally synchronized.

In prototype and sample systems, and for development purposes, in many cases a sensor fusion device BUMPER-08xx is used. This box hosts the fusion and tracking algorithms. All sensors report raw detected target lists (via a so-called internal CAN bus) along with additional diagnsotic and other data to the sensor fusion device. Here, sophisticated data association, fusion and tracking algorithms are performed. They can even generate a 360 degree picture of the traffic around a vehicle. The results are reported again via CAN (external CAN bus) or via FlexRay bus.

All fusion and tracking algorithms can be compiled to run directly on the sensor DSP (instead of the dedicated fusion device BUMPER-08xx) for cost reasons for production type sensors.

The fusion algorithms comprise beside the association of the Radar data of multiple sensors also the combination of Radar detections and the vehicle dynamics data of the host car (for ego motion compensation, lane prediction, lane history etc.).

In the picture below an example system designed for the fusion of the applications ACC and Lane Change Assist is depicted. In this case, one long range UMRR is mounted forward-looking, and two medium range sensors cover the Blind Spots and a field of view 70m back. The three devices work along with one BUMPER-08xx central sensor fusion unit.

Please see more possible options of sensor system architectures/sensor fusion setups in the document UMRR Automotive Radar Applications.pdf (475 kB).