Path tracking control of 4-wheel-steering autonomous ground vehicles based on linear parameter-varying system with experimental verification

In this study, a novel 4-wheel-steering electric vehicle is proposed as an autonomous ground vehicle. It aims to study the path tracking control algorithm of the 4-wheel-steering autonomous ground vehicle for intelligent driving.. Path tracking model is built for path tracking controller design based on a single track model. Besides, the linear parameter-varying system model is constructed to make the path tracking controller adaptive to different longitudinal velocities and road friction coefficients. Furthermore, a linear quadratic regulator controller for path tracking is designed and stability analysis is carried out. To eliminate the error caused by disturbance, feedforward control is combined with a linear quadratic regulator controller. To verify the path tracking performance of the designed controller, numerical simulations are carried out based on a high-fidelity and full-vehicle model constructed in CarSim. Moreover, real road experiments are performed. Both the simulation results and experiment results show that the designed controller has good path tracking performance. In addition, the path tracking controller shows good robustness to deal with different longitudinal velocities and road friction coefficients.