近年來隨著雷射技術的發展，雷射系統廣泛地應用在工業上。對雷射系統而言，雷射功率、雷射波長、共振腔型態、雷射振鏡機構…等，皆是影響最終性能好壞的關鍵。其中，雷射振鏡主要用於控制雷射行進方向，以及調整雷射焦距，是影響雷射焦點準確性的重要設備。本論文的目的即在於控制雷射振鏡中的galvanometer運動，使其可以快速達到所需要的定位目標。

Galvanometer是一種音圈馬達，主要優點在於慣性矩小、頻寬高，它是一反應時間可達毫秒級的機械系統。為了配合其高頻寬的特性傳統上皆以類比方式實現。但由於類比控制器受雜訊干擾的程度頗大，且修改控制律就等於重新設計控制電路，這是曠時又費力的工程。因此在本研究中嘗試設計數位控制器來操作此系統。

本研究中，採用灰盒子的方式建立galvanometer的數值模型，再利用頻率響應的方式驗證此模型的正確性。隨後，針對其特性設計兩階段的PID控制。並以PC-Based system實地控制，實驗結果顯示在20°的定位運動時，整定時間(99%)為4.15ms，此一性能已近乎所使用硬體所能達到的極限，為了更近一步提升反應速度及解析度，本研究另行設計與架構，以DSP為控制核心的數位系統。經由實地的測試，其整定的時間可以提升11.84%，僅需3.66ms。最後再針對實驗結果，設計三階段的PID控制，改善最終的性能。

With the development of the laser technique, the industrial applications have increased more than before. Laser power, laser wavelength, cavity and scan head are the key points of the laser processing systems. The scan head is the equipment which affects the accuracy of the laser focus, because it can control the direction of the laser and adjust the laser focus. In this research, we discuss how to control the galvanometer of the scan head precisely as soon as possible.
Galvanometer is one of the voice-coil motors. It has the low moment of inertia and high bandwidth. It’s a mechanical system with the settling time on the level of minimum second. To match up the characteristic of high bandwidth, the traditional technique uses the analog control. However, the noise affects the analog control very much and altering the control law is equivalent to redesigning the control circuit. Therefore, we try to use the digital control in this research.
In this research, the gray box is used to establish the numerical model of the galvanometer and then use the frequency response to prove the model. After that, the two phase PID control is designed and the PC-Based system is used to operate. The experiment shows that the settling time of the 20° position control is 4.15ms. It already reaches the extremity of the performance of the PC-Based system. In order to reduce the settling time and increase the accuracy, we use the DSP system to be the core digital system. According to the experiment, we find that the settling time can reduce 11.84%.At least, according to the result of experiments, the three phase controller is used to improve the performance.

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