Dual-Level Control Strategy for Vehicle Lateral and Longitudinal Path Following Based on Model Predictive Control

Path tracking is a key problem in autonomous vehicles, but uncertainties in vehicle models and environmental parameters as well as the couple of lateral and longitudinal behaviors pose a major challenge to path following accuracy and efficiency. To solve this problem, a layered vehicle lateral and longitudinal controller based on model predictive control is proposed in this paper. Firstly, a lateral controller based on a synthesis of robust model predictive control is used to reduce the influence of model uncertainty. Then a longitudinal nonlinear model predictive controller is proposed to achieve the coordination between the lateral following error and the longitudinal forward speed of the vehicle. Finally, the bottom PID controller is used to control the throttle and brake of the vehicle. The effectiveness of the proposed method is verified by experiments, which show that it is robust to the uncertain parameters and the computation is relatively small.