本論文提出一套新穎且架設簡易的角度量測技術-「基於Talbot 效應成像之疊紋式 角度量測系統」。本系統可分為兩部分：疊紋量測光路系統與相位分析系統。疊紋量測光路系統是將兩相隔特殊距離之雙光柵，以夾具等機構安裝於待測平台上，系統光源He-Ne Laser 搭配擴束鏡以準直光入射光柵機構，產生的疊紋影像依Talbot 效應成像於CCD。當待測平台產生角度旋轉時，裝配於一體的光柵組機構連帶產生旋轉，利用疊紋將光柵相對變化物理量放大的效果，搭配疊紋相位分析系統，便可計算待測平台旋轉角度，具有arcsec 級角度量測解析度。 本系統核心元件為兩片光柵週期介於50 ~ 200 m 之線性光柵，製作難度不高， 搭配Talbot 效應成像疊紋影像無須額外透鏡或光學元件輔助，實現高精度低成本的角度量測裝置。系統的量測解析度可藉由調整光柵間距及光柵週期來改變，具有多種組合，可依不同情況選擇適當配置。代表性的組合為200 m 光柵週期搭配1 倍Talbot距離之光柵間距(12.64 cm)，具有0.36 arcsec 角度解析度，1.06°/ arcsec 角度靈敏度，±6°量測範圍與1.36°/s 理論量測速度。;We proposed a new method based on the moiré technique and Talbot effect to measure the angular displacement. The measurement system is divided into two parts, the optical moiré system and the phase analysis system. In the first part, the collimated He-Ne laser beam is expanded by the beam expander (BE) and is forward incident into the two linear amplitude gratings, which placed symmetrically by a centre of the precision rotation stage. These two gratings can be regarded as the a spatial modulator. After passing through the gratings, the spatial modulated light beam forms a moiré pattern and is captured by the CCD camera. By adjusting the distance D between the two gratings to meet the Talbot image distance (Zt ), the clear and high contrast moiré pattern can be obtained. When the rotation stage provides a rotation, the relative displacement between these two gratings results in the phase shifting of the moiré pattern. The phase analysis by the subfringe integration arithmetic (SIA). Here, the period of moiré pattern is then divided into four areas, A, B, C and D for further analysis. By means of calculating the intensity integration of the four areas with SIA, the variation of phase shift of the moiré pattern can be obtained, and the rotation angle can be determined. This is the second part of this system. Clearly, the experimental results demonstrate that the measurement range of our system can achieve ±6°. Considering the high-frequency noise, the measurement resolution of the system is about 0.36 arcsec.
