转阀式液压助力转向系统建模与仿真分析

Modeling and Simulation Analysis of Rotary Valve Hydraulic Power Steering System

考虑了汽车液压助力转向器中的机械子系统与液压子系统,建立了相应的数学模型并利用Matlab/Simulink控制系统仿真软件建立了汽车液压助力转向系统的仿真模型。仿真分析了活塞有效面积、扭杆刚度和系统供油流量的变化对系统响应的影响情况,结果表明:增加系统供油流量、减小扭杆刚度都会使转向器的助力油压增大,此时齿条的位移将增大从而使稳定时间延长;活塞有效面积的大小几乎不影响助力油压的大小,齿条助力将随活塞有效面积成正比例变化。

Considered hydraulic mechanical subsystems and subsystems of the vehicle hydraulic power steering gear, a mathematical model was created and the Matlab/Simulink simulation model of the system was established. Simulation and analysis of the system response under different parameters indicate that increasing the quantity of hydraulic oil flow and reducing stiffness of servo-valve bar spring will improve supply pressure of the system, the rack displacement will increase and the system needs more time to achieve stability. The effective piston area has little impact on the supply pressure, the assistant forces of the rack will change proportional with the effective piston area.