Adaptive control of a composite smart structure by filtered-x algorithm

Intelligent structures with built-in piezoelectric sensor and actuator that can actively change their physical geometry and/or properties have been known preferable in vibration control. However, it is difficult, if not impossible, to model the uncertainties of laminating interfaces between composite lamina and sensor/actuator. This paper presents an adaptive filter design for system dynamics identification of a composite laminated smart structure with embedded piezoelectric sensor and actuator. An adaptive controller in filtered-X LMS (least mean square) algorithm with dynamic convergence is also developed for vibration suppression. Both the adaptive filter and the adaptive controller are implemented in TMS320C32 digital signal processor for real-time applications. Experimental verification shows that the adaptive controller is effective in vibration suppression of smart structure with embedded sensor and actuator. The control performance in resonance and random excitation are superior to active damping control.