Coordinated Control of Four Wheel Braking and Rear Steering

In this paper, we consider a coordinated control of four-wheel independent braking and rear steering. The objective of the control system is to improve the overall vehicle handling performance during combined braking and turning maneuvers. The braking and steering inputs of the driver are interpreted as vehicle deceleration and yaw rate commands, respectively. The control system is designed using the robust servomechanism design methodology and is based on a linearized vehicle dynamic model. The objective of the controller is to track the commanded deceleration and yaw rate by coordinating the four brake torques and the rear steer angle. The effectiveness of the control system is evaluated by computer simulations using a full vehicle model. Simulation results show that the integrated braking and steering control system improves the vehicle directional stability, path tracking, and performance robustness to parameter variations and uncertainties.