傳統的雷射追蹤儀(Laser Tracker)是利用一組雷射干涉儀配合雷射位移感測器(PSD)來組成追蹤儀本體，再將角耦反射鏡(corner cube)或貓眼鏡(cat’s eye)配置於受測物上做為追蹤目標。這種追蹤儀最大的優點就是應用範圍廣泛，除了可用在一般的三維空間量測外，亦可用於曲面造形以及機械手臂上的量測，但其缺點是價格過於昂貴，數學的計算與光路的組成相當複雜，以及量測不確定性較多。

本文提出了一種三維立體空間位置量測追蹤儀，為一種三維位置之量測裝置，整個系統是由兩組追蹤模組、零度角復歸子系統及一個目標位移感測器所組成。使用時是將目標位移感測器置於待測物上，當待測物移動時利用零點鎖定的方式，使追蹤模組上的雷射追蹤並鎖定目標位移感測器的原點，最後再利用三角量測法以及兩組追蹤模組的追蹤角度變化，即可求得待測物在空間中的位置。因為兩組追蹤模組的雷射是同時入射至同一個目標位移感測器。故在本研究中最主要的關鍵即為兩組雷射之位移分離技術，其主要是利用調變-解調變的方式來進行混合信號的分離，經實驗結果証實，信號的靜態偏移比率(static shift rate)為0.2 %，動態下的交叉耦合比率(dynamic cross talk rate)在2%以內。

本研究是先利用一個小型的二維空間定位量測系統來進行理論驗証、可行性的評估以及不確定性的分析，然後針對結果進行檢討並開發一套三維空間定位量測系統。在三維空間定位量測系統的設計過程中，利用了量測不確定性的分析來探討各個組裝誤差對於系統量測精度的影響，最後利用其動態特性響應分析，來進行控制器的設計。

經由實驗結果證實，雙雷射單感測器的技術確實可應用於空間量測追蹤系統，在X、Y方向300 mm與Z方向200 mm的量測範圍中，位置量測誤差小於±0.05%。本研究所提出的三維空間定位量測系統，除了可用於空間定位量測外，亦可用於曲面的量測建構及加工輪廓量測。

In the past, laser trackers consist of a tracker, which includes a laser interferometer, a position sensitive detector and some optical components, and a reflector. Two types of ref-lector, corner cube reflector and cat’s eye reflector can be used as the tracking target. Though laser trackers are widely used in the industry such as assembly of air-planes/automobiles, contouring measurement, robot calibration and so on, laser trackers are expensive, and the corresponding solution procedure is too complex. The influence of measurement uncertainties is also significant.

This study proposes a novel three-dimension space position measurement system which consists of two tracking modules, a zero tracking angle return subsystem and a target quadrant photo-diode (QPD). The target QPD is placed on the tracking object. The method of zero locking is used to make the rays stay on the zero point of the target QPD. The three-dimension space position of the target QPD is determined by the principle of triangulation. Since these two laser rays are projecting on one QPD, simultaneously. Thus, for separate the coupled positional value, the modulation/demodulation technology is uti-lized as the key technology in this study. The experiment result shows that the signal static shift rate is about 0.2% in steady state and the dynamic cross talk rate is within the range of 2%.

A two-dimension space position measurement system with small measurement range was first developed for theoretical verification, feasibility demonstration and uncertainties analysis. A three-dimension space position measurement system was also developed accor-dingly. The Measurement uncertainty analysis was used to estimate the measurement error due to the setup error and instrument error.

The experiment result shows that the measurement technology of dual laser and single detector can be applied to implement the 3D positioning measurement system. The mea-surement error of X, Y and Z direction of the three-dimension space position measurement system are less than ±0.05% within the measurement range of 300 mm, 300 mm and 200 mm for X, Y and Z axis, respectively. The proposed system can be applied to measurements of machine tools and robot arms.

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