Intelligent cruise control: theory and experiment

Automated vehicle control systems (AVCS) is an important part of intelligent vehicle and highway systems (IVHS) whose long term goal is to improve freeway capacity and safety and reduce pollution through vehicle and highway automation. An important part of an automated vehicle is intelligent cruise control that achieves automatic vehicle following in a safe, reliable, and smooth way. In this paper we present several such control systems that 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 guarantees smooth vehicle following even when the leading vehicle exhibits erratic speed behavior