Affiliations: [a] School of Electric and Automation Engineering, Nanjing Normal University, Nanjing, Jiangsu, China | [b] Concordia Centre for Advanced Vehicle Engineeing, Concordia University, Montreal, QC, Canada | [c] Nanjing Normal University, School of Electric and Automation Engineering, Nanjing, China
Abstract: A groundhook controlled semi-active suspension system equipped with magneto-rheological damper (MRD) is considered. Both the hysteresis of MRD and control discontinuity, the nonlinearity will greatly affect system stability of the vehicle. In this paper, the performance and nonlinear dynamic of semi-active suspension adopting modified groundhook is evaluated. The influence of frequency of harmonic excitation and parameter of modified groundhook controller on the nonlinear dynamics of the semi-active suspension system is investigated. More importantly, nonlinear dynamic analysis is carried out to study the semi-active suspension system, with the methods of bifurcation diagram, the Lyapunov exponent spectrum, time history, phase plane and power spectrum in detail for the first time. Furtherly, electromagnetic interference (EMI) problems induced by chaotic motion are analyzed and discussed according to EN 55022 for another first time. It is indicated that both of periodic, quasi-periodic and chaotic motions exist. The system undergoes a complex nonlinear dynamical evolution with the excitation change. The coupling influence between chaos and EMI problems cannot be ignored in the further design of the semi-active controller. This work laid a theoretical foundation for EMI reduction and nonlinear control of the intelligent MR semi-active suspension.
