Sliding mode control strategy for the four wheel drive vehicles

This paper presents a control method of torque distribution for Four Wheel Drive (4WD) vehicles. The 4WD system is a device which distributes optimal torque between front and rear propeller shafts to improve traction ability and stability of a vehicle. This paper proposes the control algorithm for the vehicle which is equipped with the electronic controlled 4WD system to improve traction ability. In this paper, Sliding Mode Control (SMC) strategy by vehicle dynamics analysis is presented. The first SMC control the front wheels torque to minimize the difference between front and rear wheel speed. The second SMC control the engine torque to reduce the slip of each wheel and to improve the fuel economy. The traction performance and the fuel economy of the proposed SMC strategy are validated by vehicle simulation using MSC´s CarSim^®.