An experimental investigation of a CW/CA system for automobiles using hardware-in-the-loop simulations

Collision warning/collision avoidance (CW/CA) systems have been an active research and development area as the interest and demands for active safety of road vehicles increase. The paper presents an investigation of CW/CA systems for automobiles. A CW/CA `hardware-in-the-loop´ (HiLS) simulation system has been designed and used to test a CW/CA algorithm, radar sensors, and warning displays under realistic operating conditions in the laboratory. A CW/CA algorithm consists of a distance warning decision algorithm and a combined throttle/brake control law for collision avoidance. The CW/CA HiLS system consists of a personal computer a preceding vehicle simulator, a radar sensor and a warning display. The personal computer has been used to simulate preceding and following vehicles. The computer calculates velocities of the preceding and following vehicles, relative distance and relative velocity of the vehicles using vehicle simulation models. The relative distance and velocity are applied to the vehicle simulator that is controlled by a DC motor. The relative distance of the vehicle simulator is measured by the radar sensor and is fed back into the computer