Over-the-air Simulation of Radar Targets and Echoes for Automotive Radar Sensors
Radar sensors play an important role when it comes to integrating intelligent solutions for assisted and autonomous driving in vehicles.
dSPACE Automotive Radar Test Systems (DARTS) can efficiently ensure the correct functioning of sensors and developed application software in different phases of the development, production, and release process for sensors and vehicles as well as for aftermarket use.
dSPACE Automotive Radar Test Systems (DARTS) form a product family for testing radar sensors for use in vehicles. With DARTS, radar sensors can be tested in the laboratory in clearly definable, reproducible scenarios. DARTS simulate object reflections – so-called radar targets – that occur in road traffic at different distances, speeds, and sizes in real time. DARTS plays a decisive role in the validation of radar-based driver assistance systems and autonomous vehicles throughout the entire value chain. Powerful devices are available for development and testing in the laboratory, for end-of-line tests during production, for the homologation of a vehicle, and aftermarket.
Over-the-air testing of sensors allows for any make of sensor to be tested without having to be integrated with a custom interface to the simulator. This means that testing can be done without having to modify the sensor, thus testing as close to reality as possible. DARTS stimulates the sensor in a closed loop environment by first receiving the radar signal from the device under test with one antenna, then introducing a delay on the signal before sending the signal back towards the sensor with a second antenna.
The delay introduced by the DARTS system is calculated based on the distance of the simulated object to the radar sensor, giving the sensor the impression that there is a target a certain distance away. When the signal is sent back towards the sensor other simulation features can be added to distort the signal as it would be in real life. For example, a doppler effect can be added to give the sensor the impression that the target is moving towards or away from the sensor.
The DARTS system can be used on its own, needing only a laptop to access the simple, easy to use, web interface for configuring the parameters such as number of targets and their distance to be emulated. This is useful for cases like validating a sensor in production or the performance of a radar chip. For more complex test cases such as testing the radar functionality in traffic scenarios, DARTS can also be used together with other automotive simulation environments like SIL & HIL simulation. SIL & HIL can be used to simulate complex parameterizable traffic and vehicle dynamics scenarios. The simulated traffic objects can consist of other vehicles, pedestrians or signposts etc. DARTS uses the information from the simulation to emulate these objects and their movements, ultimately allowing the real radar sensor to be tested in realistic traffic scenarios without leaving the lab. For test cases where a large number of targets are needed multiple DARTS systems can be used in parallel.
Given the modular nature of DARTS, the antennas can be fitted at different angles or away from the main unit. This is useful for example when testing AD/ADAS sensors that measure the angle of the received signal to determine the location of other trafficants surrounding the vehicle. For these cases an over-the-air radar test bench is used in which the DARTS antennas are fitted on axles moving around the sensor to send the signal back to the sensor from an angle. Radar testbenches come in different configurations with varying complexity that range from two to six degrees of freedom with one or multiple DARTS antennas. The different testbench concepts are:
- Essential 2D
Capable of azimuth and elevation simulation by manually altering the relative position between the DARTS antenna and the radar sensor under test. The Essential 2D testbench is capable of simulating one radar target and is used for testing simpler ADAS scenarios as well as validation and component testing.
- Compact 3D
The Compact 3D testbench is ideal for testing traffic scenarios for ADAS/AD validation. Up to 20 targets can be simulated using multiple DARTS antennas that move around the radar sensor to simulate moving targets.
- Advanced 6D
The most advanced radar test bench created for the next generation of radar sensors. DARTS antennas move freely around the radar sensor to simulate up to 8 targets with different elevation and azimuth angles in regards to the radar sensor. Suitable for testing 4D imaging radars and validating a sensors capability of distinguishing different targets, its field of view etc. The movement of the antennas and the angle is determined by the HIL traffic simulation such as dSPACE. Automotive Simulation Models (ASM) to recreate the scenario over-the-air.
For more information on radar test benches please contact sales@fengco.se.
Features
DARTS is made of high quality components to ensure precise measurements also in high frequency domains that are typically used for safety critical applications. Thanks to the high processing power, DARTS also offers a large spectrum of distance able to be simulated for the targets, ranging from as low as 60 cm to 1 km with the possibility of the target moving during simulation. In addition to this DARTS also holds the following features:
- Fully coherent generation of range, Doppler and radar cross section (RCS) as a measure for distance, speed, and size of the simulated objects
- True (single-sideband) Doppler spectrum for real-life signals
- Continuous real-time processing of radar signal waveforms
- Easy switching between radar bands
- Any modulation format: pulsed, stepped frequency, FMCW, etc.
- Center frequency can be set freely according to radar under test (RUT)
- Doppler shifts from ±100 kHz, equal to ±706 km/h
- Output amplitude programmable across an 80 dB dynamic range
If you are interested in a personal demonstration and want to know more about DARTS or other over-the-air sensor testing solutions, please contact us.
