Pre-crash systems (PCSs) use environment and vehicle dynamics sensors to improve the effectiveness of passive safety devices by activating them before a collision occurs. The autonomous character of these intelligent vehicle systems, required to anticipate dangerous traffic situations, as well as the combination of new hardware and software technologies make the design extremely complex.

This paper presents an evaluation of a PCS using the VEhicle Hardware-In-the-Loop (VEHIL) test facility. The prototype system utilizes a longrange forward-looking, installed for adaptive cruise control systems, for activation of a reversible belt retractor. The VEHIL laboratory enables testing of intelligent vehicle systems in a hardware-in-theloop environment, where only the relative motion between host and target vehicle is reproduced. The accuracy of VEHIL test setup made sensor validation and control system testing much easier and more flexible. It appeared to be useful for finetuning sensor post-processing algorithms, path prediction algorithms, and activation times.

In addition, the radar system is modeled with the PRESCAN simulation tool, which enables simulation of environment sensors in a virtual environment. The simulated sensor output can be used for development of sensor post-processing, sensor fusion and control algorithms. Also other design aspects like sensor positioning and overall system architecture can be considered.