Stabilization of chaos in electric vehicle steering systems using induction motor

This paper presents the steering system in the electric vehicle (EV) with the propulsion of an induction motor. It is found that the electric motor and associated drive system significantly increase the complexity of the steering system in contrast to the traditional vehicle propelled by the internal combustion engine, and thus deteriorate on the safety performance of EVs. In this paper, a new dynamic model of the EV steering system is proposed, which first synthetically takes into account mechanical dynamics of the steering system with the induction motor. In addition, this paper also incorporates the driver's reaction time and the external disturbances caused by irregularities of the road surface into the proposed EV steering model. It is found that the heading angle performs periodic, quasi-periodic and chaotic motions with respect to different forward speeds. In terms of the induction motor drive, consequently, this paper develops a time-delayed feedback control to suppress the unstable chaotic motions, in order to improve the safety performance of EVs. Computational simulations are also conducted to illustrate the feasibility of the proposed control algorithm. © 2013 IEEE.