Daniel G., Bueno D., Melo G., Lopes Júnior V.

The study of algorithms for active vibration control in flexible structures became an area of enormous interest of some researchers due to the innumerable requirements of excellent performance in mechanical systems as aircraft and aerospace structures. Intelligent systems, constituted for a base structure with piezoelectric sensors and actuators (PZTs) connected, are capable to guarantee the demanded conditions, through the application of diverse types of controllers. For the project of active controllers it is necessary, in general, to know a mathematical model that enable the representation in the space of states, preferential in modal coordinates to permit the truncation of the system and reduction in the order of the controllers. For practical applications of engineering, some mathematical models based in discretion methods cannot represent the physical problem in analysis therefore, techniques of parameters identification of the systems must be used. The techniques of parameters identification determine the unknown values through the manipulation of the input (disturb) and output (response) signals of the system. Recently, some methods have been proposed to solve identification problems although, none of them can be considered as being universally appropriate to all the situations. This effort presents an application of the linear quadratic regulator controller in a structure where the matrix of damping, stiffness and mass were identified by the parameters identification method by using the polynomial Chebyshev’s functions. It was considered piezoelectric actuators and sensors in optimum positions.