Adaptive precision positioning of smart composite panels subjected to external disturbances

This paper addresses the simultaneous precision positioning and vibration suppression of smart composite panels with piezoelectric patches. The filtered-x least mean square (LMS) adaptive feedforward control (AFC) for vibration/noise reduction is extended for this purpose, and AFCs with feedback loops are developed. The introduced feedback loops enhance the computational efficiency of the adaptive LMS algorithm and vibration suppression capability. Besides the classic PID feedback loop, the internal model configuration is introduced as well for the case in which the external disturbance is unknown. Experiments are performed on an active composite panel under a harmonic or random disturbance. The effects of the convergence factors of the adaptive algorithm on the overshoot and settling time of the position response of the smart composite panel are investigated. The vibration suppression and precision positioning capabilities of the AFC and the AFC with feedback loops are compared and discussed. The experimental results demonstrate that the overall positioning and vibration suppression performances for the AFC with feedback loops are better than those for the AFC.