Speed Dependent Gain Scheduled LQI based Path Following Control System Design for Automated Vehicles

Automated path following is one of the major problem in automated vehicle control. Automated vehicle should follow the desired path to minimize the lateral deviation from the path while traveling at the desired speed. In this paper, LQI control method is proposed to solve this problem. LQI based control system is designed based on speed dependent gain scheduling taking into account the effect of vehicle speed on vehicle dynamic behaviour. The proposed method is tested in a simulation environment with a high degree-of-freedom nonlinear vehicle model including steer-by-wire steering actuator model. The performance of the proposed control system is compared with PID and LQR based control systems in two different simulation scenarios. Statistical error values are used for numerical comparison of different control methods. Simulation results and error values show that speed dependent gain scheduled LQI control system equipped automated vehicle follows the desired path with less error at constant and variable vehicle speed