Discrete-Time Integral Sliding Model Predictive Control for Dynamic Lateral Motion of Autonomous Driving Vehicles

Abstract

In this paper, we present discrete-time integral sliding model predictive control (DISMPC) as robust model predictive control (MPC) in presence of disturbances. It is common to use the dynamic lateral motion of a vehicle in designing lane keeping control with a look-ahead distance. However, this model includes an external signal by curved road and the look-ahead distance in lane keeping system (LKS) and assumes that lower controller of electric power steering (EPS) has ideal performance. The external signal and the unideal dynamic model of the EPS cause poor performance of the entire closed-loop system for lateral motion control. To resolve these problems, we use discrete-time integral sliding mode control (DISMC) as an inner loop controller while MPC is used in an outer control loop. The sliding mode surface is designed to minimize the effect of unmatched disturbances generated by the external signal for LKS. MPC is applied to improve the transient response performance when tracking a path. From simulation results on the curved road, we observed that the proposed method outperforms performance of MPC with the disturbance observer in LKS.