Surrogate Bicycle Design for Millimeter-Wave Automotive Radar Pre-Collision Testing

This paper discusses the development of a surrogate bicycle target for evaluating the effectiveness of vehicular autonomous emergency braking (AEB)/ pre-collision systems (PCSs) that uses 77-GHz radar systems in detecting bicyclists on the road. The design objective of the surrogate bicycle is to produce similar optical appearance and radar response in a 76-78 GHz band as a real bicycle selected based on its popularity (in 2014) in the United States. In addition, the surrogate bicyclist needs to be able to withstand the impact of the test vehicle traveling at 30 mph (or 48 kph) should it fail to detect the surrogate target. Our design approach differs from the only other surrogate bicyclist developed by a European research group in that our surrogate bicyclist produces similar radar response as a real bicyclist over the entire 360° of azimuth angles. Our design approach began with experimental characterizing the radar cross section (RCS) patterns of real bikes of different types as well as identifying RCS contributions of different parts on a bike via accurate simulations, which were also used for design optimizations. The RCS performance of the fabricated surrogate bicycle was verified via 360° azimuth pattern measurement comparison with a real bicycle. Its physical performance was tested via actual field testing on a test track with two commercial vehicles equipped with AEB and PCS systems.