Multi-Modal Vibration Control Using Adaptive Positive Position Feedback

Abstract

An adaptive controller, Adaptive Positive Position Feedback (APPF) is proposed for the multi-modal vibration control of frequency varying structures. Spillover phenomena and real-time system identification have been obviously difficult obstacles for the multi-modal adaptive vibration control. To overcome these problems, a fast and powerful algorithm is proposed to identify the frequencies of time-varying structures. Variable PPF controllers are adjusted with estimated natural frequencies at every time step. A composite plate with a bonded piezoelectric sensor and an actuator was prepared as an experimental model, and the natural frequencies of the model are changed by attaching masses. The experimental results show that natural frequencies are estimated quite accurately and that the vibration of controlled modes is significantly reduced. No significant performance reduction has been observed with respect to approximately 10% frequency changes of the corresponding modes. On the contrary, the performance of the conventional LQG controller is significantly degraded due to frequency variations.

A review of active vibration and noise suppression of plate-like structures with piezoelectric transducers

“…The performance of the controller was experimentally shown and the vibration of the plate was reduced up to 90%. Rew et al (2002) evaluated performances of both adaptive PPF controller and a robust LQG controller for multimodal vibration suppression. Resonance frequency variation of structures, which may deteriorate the controller performance and even cause instability, was specifically addressed.…”

Vibration Control Using Input Shaping and Adaptive Positive Position Feedback

“…However, for this control method to be effective, the frequencies must be known accurately. A few forms of adaptive PPF have been developed for constrained stuctures in [32][33][34], which vary in the way they are implemented. In this paper, input shaping is combined with multimode adaptive PPF to suppress the vibrations of a slewing flexible manipulator with frequency uncertainty.…”

Multimodal active vibration suppression of a flexible structure by loop shaping

“…As the aerospace and civil industries embrace lighter and flexible structures, the need of simultaneous multimodal control increases because it is insufficient to just control the first dominant mode of the structure. Some related multimodal control research includes ∞ H control by Kar et al [13], semi-active energy rate control by Corr and Clark [14] , adaptive positive position feedback control by Rew et al [15], and LQG control Prakah-Asante and Craig [16] and Sethi and Song [17]. Additional papers discussing multimodal control are listed in references [18][19][20][21].…”