Lateral control of autonomous vehicle to track the reference path will be discussed in this paper. In the first step, double lane change path is designed using a 5th degree polynomial function (quintic) and dynamic constraints. A lane changing path planning method has been developed and used to design the double lane change path of the maneuver. In the next step, position and orientation errors are extracted based on the 2 DOF vehicle bicycle model. A combination of sliding mode and backstepping controllers is used to control the steering in this paper. Overall stability of the combined controller has been analytically proved by defining Lyapunov function and based on Lyapunov stability theorem. The main parameter of the combined controller has been obtained by defining a cost function and particle swarm optimization (PSO) algorithm. Backstepping controller has been designed and compared with the proposed controller’s simulation results to evaluate its performance. Simulation of designed controllers is conducted by linking CarSim software with Matlab / Simulink which provides a nonlinear full vehicle model. Simulation was performed for maneuvers with different durations and road frictions. The proposed combined controller has outperformed the backstepping controller, especially in low frictions.
Keywords: Vehicle lateral control; Autonomous vehicle; Backstepping controller; Sliding mode controller; Lyapunov based controllers.