Research On Key Technology Of Electric Power Steering System

The key Technology of electric power steering system used on battery electricvehicle is analyzed. It mainly moves round the analysis of assisted motor reduction gearand control system, which provides a more systematic theoretical basis to design anddevelopment. The main contents are as follows:First of all, this paper comprehensively analyzes the present reducing mechanism ofelectric power steering system. Afterward, a new type of deceleration device named pushrod movable teeth transmission is put forward. Then it emphasizes on the transmissionprinciple, movement source, mechanics source and efficiency. Based on these, thestructure of EPS with push rod movable teeth transmission is put forward.Secondly, the paper researches and analyzes the control system of EPS, which iselectric control unit. The hardware and software parts of electric power steering systemare designed. The part of hardware mainly refers to the choice of main chip and thedesign of main control circuit. Besides the part of software principally touches upon thedesign of the main program and some subroutines.Furthermore, it determines the control strategy of the basic control mode calledpower control mode, and analyzes power characteristic curves in control mode whichdetermines the power target current. Moreover, the power characteristic curve of electricpower steering system used on battery electric vehicles is designed by according to fuzzycontrol strategy. Finally, after simulation analysis, the correctness of the designed powercharacteristics curves is verified.Ultimately, the simulink simulation model of electric power steering system isestablished. The correctness of the built models is verified. On one hand, it lays atheoretical foundation for the parameters change and optimization of electric powersteering system; on the other hand, it prepares for the development and optimization ofthe system.