Proceedings Article | 1 May 1996
Proc. SPIE. 2717, Smart Structures and Materials 1996: Smart Structures and Integrated Systems
KEYWORDS: Actuators, Ferroelectric materials, Sensors, Calcium, Control systems, Transducers, Smart structures, Dynamical systems, Control systems design, Active vibration control
This paper presents a parameter based form of a wave absorbing controller (WAC) in the time domain. The controller is applied to a flexible structure with the piezoceramic transducers bonded onto it. A distributed piezosensor gives the moment rate of the wave absorbing region as an output current. This current is then fed back to a piezoceramic actuator, resulting in a wave absorbing controller. The controller is originally designed in the frequency domain by minimization of the ratio of total output to total input wave amplitudes. Although the controller performance appears satisfactory in the frequency domain, its time domain behavior is of interest for overall performance evaluation. However, the wave absorbing method usually produces controllers which are difficult to realize in practice. In order to study the behavior of the controller and closed loop system in the time domain, and also to address these realization issues, we introduce a method of approximation of the controller enabling it to be represented in a simple form. Frequency domain comparison of system performance under the original controller and this approximation demonstrates the accuracy of the latter. The system is then studied in the time domain, showing that this novel wave absorbing controller is effective and can be easily implemented in practice. The main contribution of this paper is the introduction of a new controller for flexible structures, based on the wave absorbing method (WAM), which depends on only system parameters, i.e., E, I, (rho) , and natural frequencies. Therefore, rather than the usual controller design based on dynamic model (such as LQR) for obtaining control gains, these gains can be easily calculated from a simple formula based only on the mechanical parameters of the flexible structure.
