Research And Design Of The Automotive Electric Power Steering

Electric power steering system (EPS) is a new power steering system, which emerged in recent years, uses an electric motor to provide assistance. From EPS emerged, the automotive industry attaches more and more importance to it. Comparing with traditional steering system the electric power steering (EPS) system of the automobiles is simpler in structure, more flexible, and can fully meet the requirements of steering performances. EPS also has prominent advantages in the comfortableness and security of steering, energy saving, and environmental protection.Electric power steering (EPS) system mainly combines the torque sensor, velocity sensor, electric control unit, electromagnetic clutch and gear down machine etc. In order to make the EPS run, we design the software fitting for the EPS's hardware, and the control arithmetic.The paper introduces the work principium and structure of the EPS, analyzes the influence of the steering system according to the automobile stability, basing on the B-shi model builds up the arithmetic model of EPS, designs hardware and software of EPS. In order to improve system's stability, H_∞ control theory has been used in the design of electric power steering (EPS)controller.EPS system use SCM as the control core, adopted sensor signal collection technology and LM621 chip which is a special control chip for no-brush DC motor. During the whole design course, security measures and protection has been applied in all details. Through simulation test, the EPS system's performance has been verified.