Piecewise Affine based Model Predictive Trajectory Tracking Control with Stability Guarantees for Autonomous Ground Vehicles*

Abstract

Stability and robustness are two critical performance indexes in the design of trajectory tracking controllers for autonomous ground vehicles (AGVs). This paper designs a piecewise affine (PWA) based model predictive trajectory tracking controller with stability guarantees for AGVs. Firstly, in order to capture tire’s nonlinearity and saturation characteristics as well as ensure low computational loads, a PWA tire model is built to approximate the nonlinear Fiala tire model. Secondly, thanks to the superiority of model predictive control (MPC) in dealing with state constraints, the lateral stability constraints, i.e., constraints on the vehicle’s yaw rate and side slip angle, are introduced to guarantee the vehicle’s lateral stability while tracking a predefined trajectory at high speeds. Finally, the double lane change (DLC) trajectory tracking simulation is conducted to verify the performance of the proposed control method. Simulation results show that the proposed control method remains the trajectory tracking performance as well as improves lateral stability performance significantly.