- 學位論文
具高精度與段高量測範圍傅立葉轉換三維形貌量測系統之研發
Development of Fourier Transform Profilometry with High Accuracy and Measurement Range
摘要
本論文旨在發展一高精度及段高量測範圍之數位結構光投影三維形貌量測系統，利用數位微鏡裝置(DMD)投射可隨待測物調變之正弦式結構光條紋，並以每秒擷取60張以上之高速影像，搭配創新式之傅立葉演算法進行高速三維表面重建，可有效避免因振動問題所產生之線上量測問題，並利用實例模擬業界線上量測之振動環境，以驗證本研究方法確實能達到防振之效果。同時並針對傅立葉演算法之三維頻譜進行深入探討，發展出創新式橢圓形中通濾波器，可精確擷取有效之相位信號頻譜，並與先前傳統既有之圓形濾波器進行量測精度分析與比較，驗證此方法可使三維表面形貌量測精度獲得大幅提升，並達到自動化三維形貌量測之目標。 本研究同時利用影像之二維頻譜分佈，推導傅立葉轉換演算法之量測範圍限制，並依此限制發展出頻譜分離技術，以提升其量測精度與垂直解析度。經實驗驗證之結果證實，使用單週期傅立葉轉換演算法之最大量測誤差可保持在全高範圍2.82%以內。而當使用雙週期演算法時，因相位擷取較不容易，其最大量測誤差將微升至全高範圍4.5%以內。實驗驗證此研究方法可實際應用於工業實物之三維形貌量測或動態模態分析。
並列摘要
With the maturity of high-tech manufacturing industries with applications in modern fields such as nanotechnology, biotechnology, broadband communication and optoelectronics, one of the current significant issues in obtaining accurate dimensional information and the measurement speed lies in dealing with anti-vibration problems encountered in on-line inspection environment. Thus, effective strategies for avoidance of employing expensive anti-vibration facilities or taking strict operation requirements in in-field 3-D measurement has become a critical need for manufacturing industries. This thesis aims at developing an innovating structured-light three-dimension measurement system using a digital micro-mirror device (DMD). To achieve high accuracy and avoid noisy disturbance due to in-field vibration, this method employs digital moiré patterns for high speed detection of the morphology of the measured object at a speed up to 60 frames per second. The innovative ellipse band-pass filter designed to obtain the phase information has been successfully optimized to generate 3D surface models in terms of measurement accuracy and efficiency. Meanwhile, for investigating the potential measurement slope limits for Fourier transforms profilometry (FTP), an innovation separate frequency spectrum method was developedfor measurement optimization. Our experimental results indicate that the maximum measured error can be kept within 2.82% of the overall measuring range. The developed method can be actually applied to the industry material object for dynamic characterization.