Vibration Control of Compliant Structure Using Acceleration Feedback
| Autor: | Yu-ShengLu, 呂毓笙 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 Automatic optical inspection (AOI) systems adapted on a movable gantry have been widely used in modern large area inspection tasks. The performance of motion control directly affects the accuracy and perhaps the yield of the entire process. To maximize process yield, the gantry should maneuver as fast as possible in order to maximize the throughput. However, this action will generate significant motion-induced vibration that excites the flexible modes of the systems, which may increase the settling time and reduce the inspection efficiency. As a result, a trade-off exists between the speed of movement and the achieved settling time. An alternative approach is to mount AOIs on a controllable stage and to eliminate the relative vibration between the AOI and the corresponding object to be inspected. By this approach, the effective bandwidth can be improved. However, to realize this concept, conventional position sensors cannot be used due to lacks of an absolute reference. An alternative solution is to use accelerometer for providing relative displacement by integrating the measurable accelerations. This solution brings potentially two problems: first, the possible drifting of low frequency signals and second, a re-design of feedback control scheme. By experiments, we successfully develop the anti-drift integrator, which combines two second-order Sallen-Keys high-pass filters and original model of hardware integrator for enhancing the drifting rejection. Otherwise, three controllers of acceleration feedback was designed to enhance the vibration of double clam beam test platform, Nevertheless, through detail step and sinusoidal tests simulation and experimental correlations and interactions, these three controllers have been successfully implemented.In the study, we have realized the integration of acceleration feedback controller and the model of anti-drift integrator for suppressing low frequency drifting by combining of the models of the hardware integrator and two Sallen-Key high-pass filters.. Second, by both simulation and experimental investigation, the acceleration feedback controllers have gotten less effect than the displacement feedback controllers. Although this study was motivated by the needs of AOI vibration control, it is not limited in this application only. The methodology proposed can be used in other applications related to precision positioning control using inertial sensor, such as active vibration control in precision semiconductor processing equipment. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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