Active control of flexible structures using segmented piezoelectric actuators

Author(s):  
Joseph T. Callahan ◽  
Haim Baruh
2002 ◽  
Vol 11 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Kelly Cohen ◽  
Tanchum Weller ◽  
Joseph Z Ben-Asher

Author(s):  
Ching-I Chen

Abstract This study focused on the application of active vibration control strategies for flexible moving structures which degrade into transient dynamic vibration problem. These control strategies are based primarily on modal control methods in which the flexible moving structures are controlled by reducing their dominant vibration modes. This work numerically investigated active control of the elastodynamic response of a four-bar mechanical system, using a piezoelectric actuator. A controller based on the modified independent modal space control theory was also utilized. This control theory produced overall excellent performance in terms of achieving the desired closed-loop structural damping. The merits of this technique include its ability to manage the spill-over effect, i.e. eliminate the magnitude of vibrations associated with uncontrolled modes, using only a few selected modes for control. This control was accomplished using a time sharing technique, which reduces the number of piezoelectric actuators required to control a large number of vibration modes. Furthermore, this algorithm implements a procedure for determining the optimal locations for the piezoelectric actuators. The dynamics of a steel four-bar linkage was selected with a flexible coupler separated by six elements and one piezoelectric actuator was used in the numerical simulation. The optimal actuator position was located at the third element from the right to the left. Results in this study demonstrated that a highly desired the structural vibration damping could be achieved. This control technique can be applied to transient dynamic systems.


2013 ◽  
Author(s):  
Pasquale Ambrosio ◽  
Francesco Braghin ◽  
Ferruccio Resta ◽  
Francesco Ripamonti

Author(s):  
Hui-Ru Shih ◽  
Horn-Sen Tzou

Photostrictive actuator, which can turn light energy into mechanical energy, is a new promising photoactuation technique for non-contact wireless active control of flexible structures. Optical mirrors, communication antennas, solar/optical reflectors, nozzles, rocket fairings, etc. often have the shape of parabolic shells or shells of revolution, due to their required focusing, aiming, or reflecting performance. In this paper, the active control of flexible parabolic shells using discrete photostrictive actuators is investigated. Parabolic shell of revolution is considered one of the most difficult geometry among all shell and non-shell structures. Because of this, an approximate way to estimate the dynamic behavior and light-induced control forces of a photostrictive coupled parabolic shell is presented. Based on the approximate model, the effects of actuator locations as well as membrane and bending components on the control action are analyzed. The results obtained indicate that the control forces are mode and location dependent. It is also shown by analysis that the membrane control action is much more significant than the bending control action. The validation of the approximate model is done by comparing the light-induced control forces of the photostrictive coupled shells obtained by the approximate equivalent spherical shell model and those obtained by the parabolic shell model.


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