高性能紅外線變焦鏡組之設計與成像品質控制

Abstract

紅外線變焦鏡組廣泛地運用於軍事領域中，常使用於偵察、警戒、低空探測或遠方觀測等方面，其觀測距離較可見光變焦鏡組遠，且具備不易被敵方發現、隱蔽性極佳、易觀測目標物與不易受電子系統干擾等特性。為了能夠得到高品質的光學成像與不同的視野範圍，做為軍事用的紅外線變焦鏡組，必須具備高速且精準定位之能力。 在本論文中，作者設計並實現了一套擁有兩種不同視野範圍的紅外線變焦鏡組原型，此鏡組使用了一組永磁式直流有刷馬達做為致動器、一組微處理器做為控制器，藉由與一組旋轉編碼器和一組位置感測器的合作，變焦鏡組的視野切換機構能確實完成高速且精確的絕對位置之定位。實驗結果顯示，視野切換機構可擁有平均 徑度（ 角度）的定位誤差與平均低於0.5秒的定位速度。儘管齒隙與類比轉數位不確定性的影響，但是經由旋轉編碼器、位置感測器以及控制器的合作，視野切換機構依然能夠完成高速且精確定位的目標。此外，本論文提出了切換控制法則做為紅外線變焦鏡組定位的控制策略。

The infrared zoom lens is applied extensively in the military use, such as detection, low-altitude observation and exploring. It has the features of being difficult to be found and able to easily observe the object. For military, in order to acquire a high-quality image and different FOVs (field of view), the infrared zoom lens must be capable of the high-speed precision alignment. In this thesis, we have designed and implemented a prototype of the dual field-of-view infrared zoom lens. The infrared zoom lens uses a permanent magnet DC motor as the actuator and a microcontroller as the controller. Through cooperation of two major sensor feedbacks, a shaft encoder and a position sensor, the FOV switching mechanism can achieve the goal of high-speed precision absolute alignment. Experimental results have shown a alignment accuracy average of radians and less than 0.5 second alignment time. Despite the influence of the non-zero backlash and the A/D uncertainty on the infrared zoom lens, the goal of alignment can be reached by the cooperation between the two major sensors and the controller. The control strategy, switching control, was proposed to help us to reach the goal of the high-speed precision absolute alignment.