Previous researches about vehicle lateral dynamics mainly focus on one or several
specific working conditions and make simulation analysis in the time domain to
compare the quality of the steering control system, which cannot compare the
performance of the controller as a whole. In this article, an innovative concept
was proposed to compare the vehicle steering controller. Combined with the
bifurcation theory, the performance of three different steering control systems
(front-wheel steering system, four-wheel steering system, and direct yaw-moment
control [DYC] system) can be compared intuitively from the phase plane. First of
all, taking the front-wheel steering system as the research object, the state
phase trajectory of the vehicle under certain speed and different front-wheel
steering angle inputs is analyzed, based on the established two
degrees-of-freedom (2-DOF) model of vehicle lateral dynamics. Then the influence
of the front-wheel steering angle and vehicle speed on the lateral dynamics is
further studied, and the stable driving area of the front-wheel steering system
on a high- and low-adhesion road is calculated, respectively. Finally, the phase
plane and time-domain simulations of the four-wheel steering system and the DYC
system are carried out. The results show that compared with the front-wheel
steering system, the stable driving area of the four-wheel steering control
system is significantly increased, and the stability of the DYC system is the
best.
