Control Research of Torque Compensation for Electric Power Steering System Based on Feedforward Expert System

Electric power steering system of vehicles requires that the output torque of power assistant motor will follow the driver's operation torque according to the power assistant proportion. But because of the inertia, glutinosity and flexibility, the output torque of motor is usually lag or overshoot, which will reduce the driver's driving comfort. In this paper, a type of electric power steering system whose motor column is the same as steering output column is the research object, and the author has imported expert system to the power assistant control of electric power steering system through feedforward link. The expert system can compute the feedforward torque compensation, and the power assistant torque can follow the operation torque fast, accurately and smoothly. Then the whole system capability will be improved, and the driver will feel comfortable during steering process.