The working principle of electric power steering system (EPS) is to realize the power steering of the vehicle through the joint action of components such as torque sensor, vehicle speed sensor, motor and electronic control unit (ECU).
When the driver turns the steering wheel, the torque sensor detects the rotation of the steering shaft and transmits the signal to the ECU. The ECU determines the rotation direction of the motor and the size of the power current based on the reading of the vehicle speed sensor, thereby realizing real-time control of the steering power. When driving at low speed, the motor provides greater power to make steering easier; while at high speed, the power is reduced to ensure the stability of steering.