Driving State Adaptive Control of an Active Vehicle Suspension System

A new adaptive vehicle suspension control method is presented that adjusts the controller parametrization to the current driving state and thereby enables to significantly enhance ride comfort while the dynamic wheel load and the suspension deflection remain within safety critical bounds. To this end, the adaptive controller structure dynamically interpolates between differently tuned linear quadratic regulators governed by the dynamic wheel load and the suspension deflection. The stability of the adaptive controller structure is analyzed by means of a common Lyapunov function approach taking into account the nonlinear damper characteristic of the suspension system. In order to provide a realistic framework for the controller design and the performance analysis, a quarter-car test rig based on an all-terrain vehicle suspension that has been equipped with an electrical linear motor to realize an active suspension system, is employed as testbed for the study. On this test rig, the significant performance of the adaptive control concept is successfully validated in a comparison to benchmark suspension controllers.