The Simulation Research Of Wheel Shimmy Considering Hydraulic Power Steering

Steering wheel shimmy is a common vibration phenomenon in every life; it hasvery important influence on the vehicle handling stability, driving safety andsmoothness. Through the study about this phenomenon, many valuable papers havepublished at home and abroad, but the problem is not completely resolved. In thispaper, chose the non-independent suspension vehicle as the research background,with the help of computer simulation software MATLAB and the software packageSimulink, focus on front wheel shimmy simulation analysis, the main contents of thearticle are as follows:Starting from the numerical analysis of the simplest self-excited vibration system-the van De Boer equation, according to the working principles of Rack and pinionhydraulic power steering system and rotary valve, as well as the magic formula of tire,established the mechanical and considering hydraulic power steering wheelself-excited shimmy model, comparing the time course curves and The angularamplitude curve of the two systems with different initial motivation, different frontwheel alignment parameter and different structural parameters of hydraulic system.Finally, summarize the study as follows: that the shimmy system is a complexnonlinear vibration system, whether the vibration occurs is depends on the parameterof the system, when these parameters are taken as certain value, self-excited vibrationdoes not occur, the system is convergent; when these parameters changed in a certainrange, self-excited vibration is inevitable, and can get the characteristics speed of theself-excited vibration system, but vibration amplitude is not the same; When with ahydraulic power steering system, the speed value in certain range, the vibrationamplitude is slightly bigger than the situation without hydraulic power, on the otherhand, slightly smaller than the latter. When the system convergence, the amplitudevalue of HPS is larger than the mechanical system, but the vibration fasterconvergence. With the change of the system parameters, the situation Show morecomplex changes.