Adaptive non-linear control of a clamped rectangular plate with PZT patches

The dynamic behavior and control of a clamped rectangular plate with bonded piezoelectric ceramic patches are investigated in this paper. The dynamic behavior is studied experimentally, showing that the plate exhibits dense modes, varying residual stress and non-linearity. An adaptive non-linear control scheme is then presented, which introduces a non-linear function into the normal adaptive feedforward control to non-linearize a reference signal. Vibration reductions using both the normal adaptive feedforward control and the adaptive non-linear control are compared in the cases of sinusoidal excitations at the first nine modal frequencies of the plate and a swept-frequency harmonic excitation below 100 Hz, indicating that the adaptive non-linear control can suppress not only the fundamental frequency vibration that the normal adaptive feedforward control can only attenuate, but also its higher harmonic components. Significant vibration reduction achieved by the adaptive non-linear control demonstrates its validity and reliability. (C) 2002 Elsevier Science Ltd. All rights reserved.