California Partners for Advanced Transportation Technology

In this paper, the authors present several throttle and brake control systems for automatic vehicle following. These control systems are designed and tested using a validated nonlinear vehicle model first and then actual vehicles. Each vehicle to be controlled is assumed to be equipped with sensors that, in addition to its own vehicle characteristics, provide measurements of the relative distance and relative speed between itself and the vehicle in front. Vehicle-to- vehicle communication required for the stability of the dynamics of a platoon of vehicles with desired constant intervehicle spacing is avoided. Instead, stability is guaranteed by using a constant time headway policy and designing the control system for the throttle and brake appropriately. The proposed control systems guarantee smooth vehicle following even when the leading vehicle exhibits erratic speed behavior.