Online Identification and and Vibration Control of Complex Structures Using Piezoelectric Materials

Abstract

Several advanced applications, such as those in jet fighters, automobiles and spacecrafts,require structures that are highly strong, lightweight and possess high structural damping property. A great difficulty is faced in the design of such structures due to the fact that the reduction in weight results in low rigidity and poor vibration characteristics. Unless the vibration is effectively controlled, it may destabilize the system and may, very often, result in complete failure of the system. Therefore, there is need to develop structures that are equipped with suitable vibration control features. Smart structure technology using adaptive control system may provide a solution to this problem. These structures use piezoelectric materials, electro-rheological (ER) fluids and shape memory alloys as sensors and actuators for providing effective vibration control. Active vibration control requires high sampling rate and fast processors for doing control related computations in real time. With the emergence of embedded automation, real time, dedicated processors came into existence. Using the computer based measurements active vibration control is now a practical reality. A detailed literature survey carried out for setting objectives for the present work suggests further work on the development of an online identifier/controller for estimating the parameters of a flexible structure and then using these parameters for the design of an effective controller. With this objective the present work was planned. The work has been further extended to design a controller to provide optimized near minimum time control of the structure. newline