On the active vibration control and stability of the tubular structures by piezoelectric patch-like actuators

Abstract

We present some theoretical and real-world approaches to design and implement smart vibration control of aircraft tubular structures which are controlled by feedback with power PZT patches. Experimental tests show that active vibration control and stability of a control loop may be lost at some parameters of vibration and feedback. To determine the causes of instability, a flexible tubular structure with surface-bonded PZT patch actuated is modeled by PD controller using Euler-Bernoulli beam theory. Emphasis in this study is given to the effect of actuator size and location based on the observability, controllability, and stability of the control system. Using finite element transient analysis of a beam structure with bonded PZT patches controlled by feedback, linear function of local strain and strain velocity of strain gauge placement is developed. Such action work mode can be stable both at relatively small feedback and narrow frequency band. Also, due to nonlinear nature of a coupled electro-mechanical distributed control, the suppressed vibration mode shape can be transformed to vibration of other forms. We approach to a combined method of vibration suppression according to which all actively controlled PZT patches driven at a narrow frequency band, filtering preferentially on the first eigenfrequencies. Moreover, installed shunted passive PZT patches will damp high vibration frequencies, while  simultaneously the stability of the control loop increases. Finally, we present some experimental results obtained by a scaled (1/7) helicopter rotor.