An electric power steering system provides steering assist directly by a power steering motor, eliminating a pump, a hose, hydraulic oil, a belt, and a pulley mounted on an engine, which are necessary for a hydraulic power steering system, so the system saves energy and protects the environment.
In the electric power steering system, a steering wheel torque needs to be measured in order to achieve a control of the power steering motor output torque, but the measurement of the steering wheel torque now adopts a slider, an electric brush and other mechanical components, which has a problem of low precision and high cost.