Design Of The Control System Of The Automobile's Electric Power Steering

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.In this paper, based on the mechanical structure of the electric power steering, the aim is to design the sensors' signal disposal circuits and control circuit of the whole system, to complete the control strategy and software which are suitable for the hardware, to provide foundation and reference for the EPS system's perfection.In the process of writing this thesis, first, based on the theory of the DC motor, controller and sensors, the control 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 destination is to get the assisting table, assisting torque of the motor and PDD control of the current. Finally, the examination on the platform has been carried through, which can get the relation between the steering resistance and the assisting current.The change trend of the motor's current and steering resistance is the same in principle, which proves the design of this system is correct and reliable.