光學精密量測結合機械手臂應用於直接能量沉積製程中量測與品質提升研究

Abstract

積層製造(Additive Manufacturing, AM)在近年來由於技術的快速進步和應用範圍的擴展，這項技術在各行各業中越來越受重視。在此製程中，進行線上檢測已成為一個關注的焦點。本論文旨在利用光學量測系統於直接能量沉積(DED)製程程中進行線上檢測調整，克服傳統DED只能在工件加工完成後進行品質評估的局限。在製程中調整機械手臂位置和速度，提升沉積效率，避免材料浪費，不僅能減少成本支出，也避免了工件重新製作的可能性。 本論文以方管工件為標的物，實驗了兩種常見的路徑抬升方式：單層抬刀路徑和螺旋路徑，並比較光學量測調整機械手臂位置前後的差異。在光學量測調整後，每5層之熔覆高度趨於穩定，表明本光學量測系統在穩定製程方面具有其價值性。結果顯示，原先在兩種抬升路徑下無法成型至CAM設定高度的工件，不僅能順利成型，減少了加工層數並節省了至少15%的加工時間。單層抬刀路徑的沉積效率從29.22%提升至34.68%，而螺旋路徑則從30.03%提升至35.75%。 由於本論文選定的工件為方管，熔覆過程中在平面路徑上無差異，只需調整雷射對焦位置即可成型。但實際加工中，多數工件含有曲面，需考慮其熔覆高度與CAM程式計算相匹配，方能順利成型。因此針對需要高精度要求之工件時，在調整雷射對焦位置的基礎上，額外挑選機械手臂的移動速度進行補償，根據量測結果與CAM程式設定之差值，調整機械手臂的移動速度。實驗結果顯示，隨著加工層數增加，高度誤差逐漸收斂至0.1 mm以內，加工層數與CAM程式計算相匹配並順利成型。單層抬刀路徑的沉積效率從29.22%提升至39.12%，而螺旋路徑則從30.03%提升至39.18%。

Additive Manufacturing (AM) has garnered increasing attention across various industries in recent years due to rapid technological advancements and the expanding range of applications. In this process, online measurement has become a focal point. This thesis aims to utilize an optical measurement system for online adjustments in the Directed Energy Deposition (DED) process, overcoming the traditional limitation of DED, which only allows for quality assessment after the workpiece has been processed. Adjusting the position and speed of the robotic arm during the process makes it possible to enhance deposition efficiency, avoid material waste, reduce costs, and eliminate the need to rework the workpiece. This thesis focuses on a square tube workpiece and experiments with two common path-lifting methods: layer-by-layer and spiral. It compares the differences before and after integrating optical measurement to adjust the robotic arm's position. After the optical measurement adjustments, the cladding height stabilized every five layers, indicating the value of this optical measurement system in process stabilization. The results show that workpieces, which previously could not reach the CAM-specified height under both lifting paths, not only successfully formed but also reduced the number of processing layers and saved at least 15% of processing time. The deposition efficiency of the layer-by-layer path increased from 29.22% to 34.68%, while the spiral path improved from 30.03% to 35.75%. Since the selected workpiece is a square tube, there is no difference in the planar path during the cladding process, and forming can be achieved by merely adjusting the laser focus position. However, in practical processing, most workpieces contain curved surfaces, requiring consideration of the cladding height to match the CAM program calcul