Use of Fuzzy Controller for Hybrid Traction Control System in Hybrid Electric Vehicles

In the normal condition, the front wheels follow the control trace of the driver and rear wheels follow the direction of the vehicle. The vehicle would spin and lose the control trace of the driver if the traction force is greater than the friction force. Therefore, a vehicle should maintain an adequate slip ratio of the tires and follow the control trace of the driver. This paper described a fuzzy controller for hybrid traction control system in hybrid electric vehicles (HEVs) that prevented the spinning of the drive wheels during take-off and acceleration through targeted, brief brake impulses in motor torque. The task is to have the fuzzy supervisory controller generate the electric brake torque, for motor of a HEV. The electric brake torque is treated as reference input regenerative braking torque, for lower level control modules. When these lower level motor controller tracks its reference input, the desired slip ratio, can be reduced. Emergency lane change, tire slip ratio change simulations and experimental results were performed to show the effectiveness of the control. The efficiency and easy implementation of the fuzzy controller lead to the conclusion that fuzzy logic is an adequate and promising framework for hybrid traction control system in hybrid electric vehicles