Influence Of Electro-Hydraulic Power Steering To Handling And Stability Of Vehicle

Vehicle handing stability not only affects the control convenience of vehicles, but also is a key capacity which determines the high-speed vehicle safety.The steering system for controlling vehicle traveling direction strongly affects vehicle's handling and stability.This paper studies the influence of Electro-Hydraulic Power Steering(EHPS) to handling and stability of vehicle.In the paper,the math model of EHPS was built firstly,then in the Simulink module of Matlab software,there is built the simulated model of EHPS.The relation of the motor speed,the vehicle speed and the steering speed is analyzed,and BP nerve network is used to simulate its curve.The Brushless DC Motor,important part of the system is well controlled by two-closed-loop control method,and the simulated model of motor is built according as control policy and math model.In the paper,perform step angle input simulation test of steering wheel under different vehicle speeds,different step input speeds and different steering parameters. From the simulation analysis,we can get yaw angular velocity,lateral acceleration and hydraulic power and so on response.The influence of these parameters on vehicle's handling and stability of the system is analyzed and the improvement methods of vehicle's handling and stability are put forward.The text does performs steering wheel angle step input test,steering efforts test and steady static circular test with a car according to GB/T6323-94 Vehicle Handling and Stability Test Procedure.The simulation model is correct,which is testified by comparing the test results and the simulation results of yaw angular velocity and lateral acceleration.The simulation results can provide theoretical basis for designing EHPS and improving vehicle's handling and stability.