The Flexible Arm Active Control Study

Flexible large space structures are of small damping mode, small natural frequency and low frequency-intensive, and the vibration problems acquire extensive attention. Due to the advantages of light quality, wide frequency and strong adaptability, piezoelectric ceramic as a kind of intelligent materials is widely used in the vibration control of flexible spatial structure.A high order finite element model of a duralumin flexible beam with distributed piezoelectric sensors and actuators was presented in this paper. The beam equation was developed incorporating the stiffness, mass and electromechanical coupling effects of the piezoelectric apparatuses. By the skills of dynamic contract, the degree of freedom was decreased in favor of the design of controller.After analyzing the characteristics of this simplified model, The linear quadratic regulator approach, fuzzy control and fuzzy adaptive PID were designed for active vibration control with the structure subjected to impulse disturbance. And simulations of the closed-loop system with these three methods are performed well in MATLAB. In experiment, experimental control software of the beam which is friendly interface and more features is programmed by VB. The vibration parameters are identified firstly, and then drive the beam to vibrate through the imposition of sine or random signal. The right algorithm was actualized to take active control, and the results show that the effect of vibration suppression is good.