R-type Electric Power Assisted Steering Device’s Structure Design And Parameters Optimization

Electric power steering system is directly dependent on the electronic control unit to the motor to provide power, which meets the vehicle steering portability at low speed and high speed road feeling requirements. EPS is a good solution to the car to ’light’ and ’spirit’ of the contradiction, and also has the advantages of energy saving, environmental protection etc.This paper analyzes the current situation of the development, classification, composition and working principle of the electric power steering system. The R-EPS as the research object, according to the specific vehicle steering resistance requirements, designs the gear-rack mechanism with a boosting gear, and the system of the strength check and CATIA 3D modeling and virtual assembly.According to the EPS system in power requirements and convenient and installation requirements must match with the vehicle, analysis of the matching of the motor and the speed reducer and design their related parameters. By using MATLAB optimization of nonlinear functions in the toolbox(fmincon) and genetic algorithm, the helical gear-worm mechanism of reduction mechanism is optimized. And analysis of the helical gear-worm stress.The structure parameters of the torque sensor of torsion bar is designed. Using ANSYS Workbench software to optimize the design of torsion bar, compare to torsion bar before and after the optimization, and fatigue analysis for torsion bar.Using a variety of software, design, analysis and optimize the main part of the system, and provides a method of rapid design and optimization for electric power steering.