Dynamics Simulation And Experimental Research Of Hydraulic Power Steering System

This paper introduced the structure feature and working principle of themechanical components of the hydraulic power steering system with rack and pinionin detail and summarized the research theories and methods used in the previousstudies of the hydraulic power steering system. Using modeling, simulation andtesting methods respectively to investigate the dynamic characteristics of the system.To begin with, developing a model of the system including mechanical andhydraulic subsystems, and using the numerical analysis method to obtain the timedomain responses of the system.Then, developing a state space of the system incorporating the mechanical andhydraulic subsystems. Deriving the system coefficient matrices in order to obtain thefrequency domain responses of the system. Using root searching method to determinethe natural frequencies and corresponding modes of the steering system.Furthermore, comparing the results obtained from the frequency domain analysiswith those obtained from the transient analysis. The result illustrated the dynamiccoupling between the mechanical and hydraulic subsystems.Finally, designing and building a hydraulic power steering system test rig, whichprovided an approximately realistic working environment for the hydraulic steeringsystem, to validate the mathematical models and simulation results. Performing aseries of experiments including the hammer testing of the front wheel, the steeringshudder testing and the pressure ripple testing. Dealing with the experimental data,comparing and analyzing the data with the simulation results from time domain andfrequency domain. The experimental results confirmed the presented modeling andsimulation analysis.The models and test rig may assist in performing theoretical noise and vibrationanalysis of the steering system for optimizing its performance.