Adaptive Output Feedback Control of Bouc-Wen Hysteretic systems

The hysteretic behaviour is an essential feature of many technological systems e.g. magnetorheological suspensions, buildings dampers, etc. In these systems, the hysteretic behaviour is conveniently accounted for through the well known Bouc-Wen model. But this involves several unknown parameters as well as internal signals that all are not accessible to measurements. Furthermore, not all parameters come in linearly. All these difficulties make hysteretic system control a challenging problem. Previous solutions have simplified the problem supposing some of the inaccessible internal variables to be measurable or some unknown parameters to be available. In this paper, a high-gain type adaptive output feedback controller is developed which contrasts with the previous solutions. It is shown that the resulting closed-loop control system is shown to be globally stable and the output reference tracking can be made arbitrarily small by choosing conveniently the design parameters.