An SIMO Nonlinear System Approach to Analysis and Design of Vehicle Suspensions

Vehicle suspension (or vibration control) systems are usually inherently nonlinear and can be modeled as single input multiple output (SIMO) system. In this paper, parametric convergence bounds for Volterra series expansion of nonlinear systems described by a SIMO nonlinear auto-regressive with exogenous inputs model are studied in the frequency domain, which can clearly indicate the parametric range in which a given nonlinear system has a convergent Volterra series expansion, referred to as parametric bound of convergence (PBoC). With the resulting PBoC of characteristic parameters, nonlinear systems with a nonlinear multiobjective performance (MOP) function can then be analyzed in the frequency domain using a nonlinear characteristic output spectrum method based on the Volterra series expansion. To demonstrate the results and method above, a vehicle suspension system, which is taken as a typical SIMO nonlinear system with a MOP function to optimize, is investigated. The results demonstrate a systematic and novel method for nonlinear analysis and design.