4WS vehicles lateral control via a modified exponent reaching law

Lateral control for Four-Wheel-Steering (4WS) vehicles on Automated Highway is investigated. Based on the previously studied look-down reference system with front and rear sensors, lateral dynamics model of 4WS vehicle is analyzed and model parameters uncertainties and external disturbance are considered. A sliding mode controller is designed based on a modified exponent reaching law, which integrates some states into the switch term to eliminate the chattering, and then the controller is applied to the lateral control for a 4WS vehicle. Simulations are conducted to evaluate the performance achieved by the proposed controller under different velocities and road adhesion factors, and effectiveness of the proposed approach is verified by the results.