An analytically derived reference signal to guarantee safety and comfort in adaptive cruise control systems

Abstract

Collision prevention is the most important issue in designing adaptive cruise control (ACC) systems. In these systems, passenger's safety and comfort requirements are satisfied by tracking a reference signal which determines the inter-distance policy between vehicles. The time gap between the system initial state and its steady state should be reduced as much as possible so that any collision due to frequent acceleration or deceleration would be prevented. To this end in this paper, a novel reference signal for the ACC system is proposed which guarantees passenger's safety in various system initial states by adding initialization factors in the inter-distance policy. The proposed reference signal is analytically derived from the system equations, considering both relative distance and initialization speed of the host and front vehicles. The final model of this approach is a linear reference model which also shows some improvement in passenger's comfort. To evaluate the proposed method, it is compared with two older reference signals in several initializations and steady states. The simulation results show that our method can prevent collisions in all initialization scenarios and also show several improvements in comfort behavior in the steady state.