Abstract: Output saturation of adaptive controllers and the resulting influence on the adaptive control of structural vibrations are discussed with the focus on saturation alleviation. On the basis of tracking filtering and the filtered-X LMS algorithm, a method for weight updating is obtained by utilizing the sigmoid function in the constrained optimization of controller parameters. The presented method can ensure a controller to fast escape saturation and reduce structural vibration to a lower level in a shorter time. Numerical simulation is conducted to investigate the influence and suppression of controller saturation. The results demonstrate the effectiveness of the proposed method in saturation alleviation and the performance improvement in adaptive vibration control.

Key words: Adaptive control, Filtered-X LMS, Output saturation, Vibration control