Dynamic characteristics analysis of hydraulic pipes in fully hydraulic steering system of engineering vehicles

Based on power bond graph diagram method,the general mathematical model of fully hydraulic steering system(FHSS) was established.The dynamic characteristics of hydraulic pipes of FHSS and the influences of pipeline parameters on the steering system were mainly analyzed by using 20sim bond graph software.The study results show that for the long and small diameter pipeline steering systems,the fluid resistance and fluid sense get larger,which are conducive to suppress high-frequency oscillation and shock to enhance the stability of steering system,but prolong the system's dynamic response time;for the short and large diameter pipeline,the fluid resistance and fluid sense get smaller,the system responses rapidly,but the steering system endures intensive high-frequency oscillation,with the increasing of both amplitude and frequency,which is unconducive to the stability of steering system.Increasing the volume elastic modulus of oil in the system can improve the dynamic response speed and stability.The study results provide a theoretical support for the design of fully hydraulic steering system and for the analysis of pipeline nets'dynamic characteristics.