Control of a semi-active suspension with a magnetorheological damper modeled via Takagi-Sugeno

Abstract

Magnetorheological (MR) dampers have proved to be an attractive solution in improving vehicle stability and passenger comfort. However, handling with these dampers, which contain highly nonlinear phenomena, implies a strong effort in modeling and control. This research presents a Takagi-Sugeno (T-S) fuzzy model, not reported before, for a two-degrees-of-freedom (2-DOF) one-quarter-vehicle semiactive suspension with an MR damper. The objective is to prove that an MR damper, represented by the Bouc-Wen approach, is suitable for control purposes. Moreover, the model developed in [14], was reformulated into a more compact control-oriented model. The stability condition is given in terms of Lyapunov stability theory, and carried out by means of Linear Matrix Inequalities (LMI). Due to system's fuzzy nature, the controller gain is applied via Parallel Distributed Compensation (PDC) through a static state feedback controller for each linear subsystem. The advantage of having the T-S system as a reference is that each piecewise linear system can be exposed to the well-known control theory regarding: stability, robustness, and performance. Besides, the novel model encloses the nonlinear damper phenomena, avoided in another reported work, i.e. [9], and [11], which can improve the suspension study by means of a more accurate model. A numerical case and simulation work support the results. This research introduces a more accurate control oriented model that can be applied in the suspensions performance domain towards comfort and stability improvement.