Electric power steering system and control method

The invention discloses an electric power steering system and a control method. The electric power steering system comprises a collector, a processor, a fuzzy PID controller and a motor, wherein the collector is used for collecting manual torque applied to a steering wheel and the current speed of the vehicle; the processor is connected with the collector for receiving the manual torque and the speed, acquiring expected target steering torque applying to the steering mechanism after the motor is power-on according to the manual torque, the speed and the preset steering control strategy, and further acquiring target current needed when the motor outputs the target steering torque; the fuzzy PID controller is connected with the output end of the processor for receiving the target current and the present current of the motor, adopting fuzzy PID control algorithm to adjust the output current of the fuzzy PID controller according to the target current and the present current of the motor until the present current is the same as the target current; and the motor is used for controlling the steering mechanism according to the output current of the fuzzy PID controller. Accuracy and stability of the electric power steering system are enhanced.