多自由度撓性結構系統之振動控制

殘留振動的存在問題，影響了系統定位的準確度，因而增加了達到工作目的之安定時間。先前的研究針對撓性結構系統之衍架板作單軸運動之振動抑制，利用PD及模糊(Fuzzy)控制器控制伺服馬達作精準定位控制，衍架板上之感測器回授經控制器輸出至壓電陶瓷之作振動抑制。本研究之目的在於雙軸同時作動時，降低衍架板因轉動造成的殘留振動影響。針對殘留振動的影響，本研究將撓性結構平台做了部分的改良，以減少因結構影響所造成的振動，並利用正弦波軌跡追蹤證實，平台在經過改良後機構造成的振動影響是有被改善的。接著探討於撓性結構的所引起的殘留振動，常用的一種減振的控制方法「輸入修正法(Input Shaping)」。本研究利用輸入修正法(Input Shaping)中的ZV Shaping(Zero-Vibration Shaping)，以及步階疊加的方式來探討其減振效果。根據研究得到的實驗數據證實，輸入修正法在撓性結構上能有效的降低因運動引起的殘留振動。

關鍵字

輸入修正法； PD控制；殘留振動；撓性結構

並列摘要

Since the flexible structures have the property of light weight and large dimensions, these structures normally demonstrate very low damping ratios and relatively low natural frequencies. As the result of the flexibility of elements of the structure, undesirable residual vibration may occur. Such residual vibration problems will affect the positional accuracy of the system, thereby increasing the settling time to achieve the purpose of work. Previous studies for vibration suppression of truss type plate are only deal with single-axis motion. Thus, the main goal of this study is the multi-degree-of freedom structural vibration control of the truss plate. Two control methodologies which include step superposition and Zero-Vibration Shaping (ZVS) have been proposed for vibration control of such structure. Experimental results are also presented which show that in using such controllers, roll and yaw angles control and elastic mode stabilization are accomplished in spite of uncertainty and external disturbance. The broad range of problems discussed in this research will be found useful in civil, mechanical, and aerospace engineering, for flexible structures with multiple degree-of-freedom motion.