Frequency-shaping observer-based controller design for actuator degradation: Application to suspension system

The main contribution of this paper is a methodology, derived from $\mathscr{H}_{2}$ cost functional, Parseval's Theorem in controller design and the principle of unknown input observer, for the estimation and accommodation of polynomial actuator degradation. In this design, the observer-based controller, integrated with a frequency-shaping filter and a state-feedback compensator, attenuates the disturbance influence on observer estimation and maintains the system stability. Furthermore, due to its simplicity, industrial engineers and readers can easily apply the proposed method to health maintenance system. Finally, an application to suspension system is illustrated to highlight the performance of the proposed method.