優化數位影像相關法並應用於跨尺度問題的精密量測與系統整合

Optimizing Digital Image Correlation Method and Applying to Multi-Scale Measurement and System Integration

陳義翔(Yi-Xiang Chen)

指導教授 ： 馬劍清

國立臺灣大學/工學院/機械工程學研究所/碩士(2020年)

https://doi.org/10.6342/NTU202002813

摘要

數位影像相關法(Digital image correlation, DIC)是一種非接觸且全場式的光學量測技術，可應用於跨尺度與跨領域的工程問題上，其原理為透過數位影像序列分析，追蹤待測物表面的灰階特徵，計算位移、速度、加速度及應變等物理量。本文首先提出數位影像相關法的優化方法，解決特徵縮放與旋轉之限制，其中包含搭配相機自動對焦功能達到二維面外方向追蹤的目的，以及開發以內插法為計算基礎的旋轉量測演算法並應用於機械手臂量測。本文探討數位影像相關法與熱膨脹相關之問題，量測工業相機熱膨脹量值與穩定所需時間，以及應用於內藏式高速主軸的熱伸長量測並藉由光柵光纖感測器驗證量測結果準確性；此外，探討機械手臂於高速運動急停時產生的振動問題，以及討論複雜軌跡運動下的精度，說明了無論是長時間且具微米級的位移量，或是大範圍快速運動且具公尺級的剛體運動問題，數位影像相關法皆能有精確的量測結果，驗證其跨時間與跨空間尺度的量測能力，將量測結果與雷射都普勒測距儀與加速規比較後，也驗證數位影像相關法有同時量測位移、速度、加速度之能力。除了機械手臂的性能量測，本文也致力於多系統的整合，建立機械手臂的回授系統，連結數位影像相關法的量測能力與機械手臂的運動能力，更連接精密平台的精密位移運動，發展多系統的協同運動之應用。最後深入討論三維數位影像相關法於不同層面的應用，對於純平移的運動，藉由機械手臂驗證數位影像相關法的大範圍定姿運動量測能力，以及藉由三次元量床驗證其定量量測能力，評估數位影像相關法的位移量測精度與重覆精度；此外，對於具三維六個自由度的複雜剛體運動，將前述之旋轉量測演算法推廣至機械手臂三維運動問題，並建構相機與機械手臂的座標關係，計算機械手臂的姿態，發展以數位影像相關法量測機械手臂軌跡精度之方法，可用於開發更貼近實務需求之應用。

關鍵字

數位影像相關法 ； 跨尺度 ； 三維量測 ； 熱膨脹量測 ； 工具機主軸 ； 機械手臂 ； 三次元量床 ； 座標轉換

並列摘要

Digital image correlation(DIC) is a non-contact and full-field measuring technique for diverse engineering problems. This thesis proposes the optimization method of size-changing and rotating region of interest(ROI) features. In size-changing problems, it’s successful to track the features in out-of-plane direction combined with the auto focus function of digital single-lens reflex camera. In rotating problems, this thesis develops the rotation algorithm based on interpolation and applies it to the motion measurement of robotic arm. In thermal deformation problems, this thesis measures the thermal expansion magnitude of camera and lens and identifies the stable time needed. Besides, the measurement of the high-speed spindle’s thermal extension is a significant issue for manufacturing and this thesis verifies that DIC is a suitable technique for this problem through comparison with FBG. Also, applying DIC for measuring the vibration induced by suddenly stop of robotic arm at high speed and the accuracy measurement of complicated trajectory movement indicates that whether the thermal extension in long-term and micro-scale or rigid body motion in short-term and meter-scale, DIC results are proved to be accurate and precise. Compared to LDV and accelerometer, this thesis verifies DIC can present displacement, velocity and acceleration at the same time. Furthermore, system integration is also an important contribution of this thesis, we implement DIC measuring system into robotic arm and precision stage to construct the feedback system of robotic arm. At last, this thesis evaluates the precision of DIC results through the pure translation motion of robotic arm and coordinate measuring machine(CMM). For complicated rigid body motion, this thesis expands the rotation algorithm to 3D motion problem and constructs the coordinate transformation between the camera and robotic arm to evaluate the trajectory precision by DIC.

並列關鍵字

Digital image correlation, ； Multi-scale ； Three-dimension measurement ； Thermal expansion measurement ； Spindle ； Robotic arm ； Coordinate measuring machine ； Coordinate transformation

參考文獻

參考文獻

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