Dynamic Control and Simulation of Leader-follower Vehicle Formation Considering Vehicle Stability

Abstract

In this letter, a control strategy comprising velocity and yaw rate controllers is proposed for a real fourwheel vehicle in a leader-follower formation when the leader vehicle drives at high speed, i.e., 100 km/h. Since vehicle stability plays an increasingly important role as speed increases, vehicle dynamics must be considered in vehicle formation control. Therefore, to increase the accuracy of the formation geometric model, bicycle modelbased leader-follower formation models are suggested, which are denoted as the follower (F) bicycle model and the leader-follower (LF) bicycle model. Then, the velocity and yaw rate control of the follower vehicle is designed. In addition, vehicle longitudinal and wheel dynamic models are considered in the velocity control to generate the wheel torque. Finally, the control gains are determined under conditions that satisfy the Routh-Hurwitz stability criterion, which guarantees the stability of the vehicle simplified as a first-order lag model. The performance of the proposed leader-follower bicycle model and controllers are strictly demonstrated by implementing vehicle dynamics simulations in cases when vehicles in a formation drive at high speeds. The simulation results confirm that the suggested formation control strategy can be applied to real four-wheel vehicles under high-speed conditions on various types of paths, in comparison with the unicycle model-based formation shape model.