Adaptive cruise control considering trade-off between distance and acceleration

Abstract

In adaptive cruise control (ACC), it is important to improve ride comfort and safety. Distance and acceleration have a significant influence on ride comfort and safety, and there is a trade-off relation between distance and acceleration. Therefore, driving characteristics of ACC should be changed according to various driving scenes. This paper proposes control strategy and design method considering a trade-off between distance and acceleration. In proposed control strategy, driving behavior of ACC is expressed by combination of transient behavior and steady behavior. An example of transient behavior is approaching to a slow vehicle, and an example of steady behavior is following to a breaking vehicle. The proposed control is based on 2-degree of freedom control, it consists of feedforward and feedback controllers. A feedforward controller is designed for transient behavior, and a feedback controller is designed for steady behavior independently. In proposed control design method, driving characteristics for transient behavior is defined by 2-stage moving average filter. Time constants of the filter are theoretically linked to the required distance response and acceleration response. Simulation results show that driving scenes of ACC is expressed by combination of transient behavior and steady behavior. In addition, 2-stage moving average filter defines the response of ACC directly, it contributes to consider a trade-off between distance and acceleration.