Abstract
In this paper, a mathematical model of a typical rack and pinion hydraulic
power steering system is briefly introduced. Numerical analysis is then conducted to obtain
the natural frequencies, the mode shapes and the time domain responses of the power steering
system. A test rig is designed and built to verify the mathematical model. The test facility can
adjust the loads of the two front tires to simulate the different operating environments. The
pressure fluctuation of the working fluid in the feeding pipes and the acceleration of the front
wheel are measured. The numerical results agree well with those obtained from experiment.
Keywords - Hydraulic power steering, fluid circuit modelling, steering shudder.