Effect of braking torque on vehicle nonlinear dynamics

Abstract To analyze the effect of braking torque on vehicle nonlinear dynamic characteristics, a five-degree-of-freedom(5DOF) vehicle nonlinear dynamic model including braking torque is established in this paper. The global dynamic characteristics of the model are analyzed through the phase space of multiple initial points. The effect of constant braking torque on vehicle dynamic characteristics is studied by time-domain analysis and tire force distribution characteristics of a single initial point. The characteristics of bifurcation and chaos are analyzed by using the differences in trajectories in phase space, the bifurcation diagram of state variables and the Lyapunov exponent spectrum. The results show that the braking torque has a significant impact on the vehicle’s nonlinear dynamic characteristics; With the increase of the braking torque, the five-degree-of-freedom model system may occur multiple bifurcations and hyperchaos under the condition of the zero-steering angle of the front wheel; some instable vehicle dynamic states under zero front-wheel steering angle can only be restored to a stable state with the action of braking torque in a certain range of values.