A Sliding Mode Control approach to longitudinal control of vehicles in a platoon

In the actual driving conditions, such as a smooth curved path or complex road traffic conditions, the velocity of the platoon often changes in acceleration or deceleration, which will cause the increase of the spacing error obviously, even cause the platoon system instability. So a robust control technique is applied to solve this problem. The robust control strategy adopted in this paper is Sliding Mode Control (SMC), which has a great robustness to system parameters change and external disturbances. Two controllers are designed to control the velocity of vehicles and direction in the platoon in this paper. The longitudinal controller is controlled to regulate the longitudinal distance between vehicles at a desired spacing using the sliding mode control technique. The lateral control aligns the vehicle direction by the steering controller which is actually a PID controller. The experiment simulations show that the designed model can realize the stability of vehicle tracking control. The designed two controllers can ensure that the vehicle stays on the reference path, and the platoon has a relatively small spacing error and lateral error.