Surface-mounted thin-film actuators in pointing systems applications

In this paper, high-fidelity modeling, precision positioning, vibration and disturbance attenuations, as well as tracking control problems for flexible beams with thin-film PZT actuators are studied. The mathematical models of the beam are described by partial differential equations. Nonlinear actuator dynamics are integrated to perform design, and guarantee accurate performance analysis with outcome prediction. Forces developed by the PZT actuators are applied to properly position the beam, attenuate vibrations and minimize disturbances. It is illustrated that high-fidelity mathematical models of actuators must be integrated because nonlinearities, hysteresis and other phenomena cannot be neglected. These nonlinear effects significantly degrade overall performance and, therefore, the control problem must be solved. To guarantee the optimal performance, robust tracking control algorithms are designed using proportional-integral control laws with state feedback. A novel design method is applied. In addition to the solution of the tracking control problem, the parametric optimization problem must be examined. In particular, we examine the system performance using different numbers of thin-film actuators and optimize their locations. The results reported are new and have not been previously reported in the literature. The proposed mathematical models, design procedures and optimization are verified through heterogeneous simulations and data-intensive analysis using the MATLAB environment.