Research And Simulation Of EPS Steering Power Control Strategy In Heavy Vehicles

EPS (Electric power steering) technology has been widely applied in the field of low power EPS, overcome the deficiencies of traditional power steering system, and improved the steering performance of the automobile. EPS is the development trend of power steering technology and has great prospects. However, in heavy vehicle, steering system still focuses on hydraulic steering but EPS. With the advancement of technology of EPS, the scope of the study has expanded from low power to high power. At present, there have been some related units in the domestic has launched the previous research work in high power area..In order to apply the EPS technique to heavy vehicles, this paper aiming at control system inertia, fast response and adaptability etc in the high power EPS. And the theoretical analysis, study and simulation of the EPS power control strategy for heavy vehicles are presented on the basis of the existing low power EPS technology.This paper has demonstrated the problem of the performance index in the EPS. the result showed that the system should follow the performance index of force tracking, rather than the performance index of angle tracking. We also analyzed several working state of the power steering, the power return, the damping return, the damping centre after determined the performance index.The physical hardware was selected, designed and modeled on the basis of the analysis of the characteristics of heavy vehicles EPS. The recirculating Ball Steering Gear, permanent magnet brushless DC motor and retarder were selected, and designed the overall layout of the recirculating Ball Steering Gear type EPS system for heavy vehicles.The power steering control mode is discussed important about the control strategy of EPS. A two-lay structure controller is put forward on EPS of heavy vehicles. They are the target current control and power motor control. The sugeno-fuzzy control, inertia compensation and fuzzy PID integrated control strategy were designed respectively base on power control mode, followed the establishment of steering assist characteristic and inertia compensation.Finally, the EPS of the heavy vehicles power steering control strategy is validated by simulation in Simulink. The simulation results showed that the control strategy can be achieved on the system stability, response speed, frequency etc and can provide a theoretical reference in future development and application for EPS of the heavy vehicles.