DESIGN OF AN ON-DEMAND ALL WHEEL DRIVE CONTROL SYSTEM FOR IMPROVED AUTONOMOUS NAVIGATION

This paper presents a novel control law for an on-demand all wheel drive vehicle for traction enhancement that will result in improved autonomous navigation. Based on a single track vehicle model and optimization of a performance index based on wheel slip, a closed loop actuator control law is derived. The proposed controller tries to minimize the wheel slip error by dynamically transferring the drive torque from the default driven wheel pair (e.g. front wheels) to the non-driven wheel pair (e.g. rear wheels), in order to enhance vehicle longitudinal traction. Simulation of the proposed controller was performed on a validated 14 degree-of-freedom detailed vehicle model in SIMULINK. The simulation results show that the proposed control algorithm provides very good acceleration slip regulation in a vehicle traction maneuver on low friction coefficient surfaces when compared with that without the controller.