Study On Control Logic Of Electric Power Steering And Design Of Detecting Circuit

Along with the development and progress of the automobile and the electronics technology, the steering system has experienced many types such as mechanical steering, hydraulic control steering and electric power steering. The power steering system has an assisting organ, which can lighten the driver's steering force. EPS(Electric Power Steering) uses advanced electronics technology and motor control technology in the steering system, the direct power source is not the engine but the DC motor. EPS can improve the dynamic and static performance of the automobile, reduce energy cost and pollution, improve the driver's coziness and security. So the research and development on EPS has far-reaching meaning.Based on the mechanical structure of the electric power steering, sensors' signal disposal circuits and control circuit of the whole system, this paper aim at designing the detecting circuits, to complete the whole system's control strategy and software which are suitable for the hardware, to provide foundation and reference for the EPS system's perfection.On the basis of the theory of DC motor, controller and sensors, the detecting circuit has been designed. The reliability of the circuit has been examined through the imitation and check to the circuit board. Later, the control strategy and the software have been designed, the primary target is to get the assisting table, assisting torque of the motor and PID control of the current. Finally, the test on the platform has been carried out, which can get the relation between the steering resistance and the assisting current as well as get the relation between the steering angle and the time in process of returnable control.The trend of the motor's current and steering resistance resembles in principle and the returnable control work well, which proves the design of the system is correct and reliable.