Study on the bifurcation character of steering wheel self-excited shimmy of motor vehicle

Bifurcation theories of nonlinear dynamics and stability theories of ordinary differential equation have been considered to elaborate the bifurcation character of steering wheel self-excited shimmy of motor vehicle. It has been theoretically proved that the self-excited shimmy is a vibration phenomenon of stable limit cycle occurring after Hopf bifurcation. Some control objectives to attenuate the shimmy have been proposed on the basis of its bifurcation property, and preliminary exploration has been made on research methods of shimmy control strategies. A simple shimmy model of three degrees of freedom, parameters of which come from a truck with independent suspension, has been constructed as an example to conduct numerical analysis of bifurcation property, road test and numerical simulation. The results confirm the conclusions.