Optimization Controller Design of Full-Vehicle Suspension System Based on Bicubic Positive-Real Impedances Realizable with Five Passive Elements

This article investigates the passive controller design problem for a full-vehicle suspension system, where the passive controller consists of four positive-real bicubic impedances realizable as two-terminal five-element damper–spring–inerter networks. The state-space model for the full-vehicle suspension control system is formulated, and the corresponding comprehensive performance index is defined. Then, combined with the recent passive network synthesis results for a bicubic function to be realizable with five elements, the passive optimization problems are investigated. The results show that the passive controller corresponding to the optimal bicubic positive-real impedances realizable with five elements can significantly improve the individual system performance and the comprehensive performance, compared with the conventional structure case and the general biquadratic positive-real case. The findings of this article can simultaneously enhance system performance and reduce the complexity of the physical mechanical network realizations.