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  • 學位論文

五軸工具機之幾何誤差補償方法探討

指導教授 : 陳世樂 高永洲
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摘要


幾何誤差是影響五軸工具機加工精度的關鍵因素之一,只要能降低幾何誤差,勢必能提升機台整體加工精度。本研究聚焦在於建立一套完整幾何誤差模型,用於鑑別旋轉軸幾何誤差,而量測方面,儀器則是採用雙球桿循圓量測儀(Double Ball Bar, DBB),並搭配三條規劃好的量測路徑、量測NC碼與量測操作標準步驟,量測旋轉軸在運動過程中的總和誤差。綜觀目前市面上可量測五軸工具機幾何誤差的量測儀器,其價格皆超過百萬,相較之下DBB廉價許多,加上DBB已經是工具機廠的標準配備之一,操作也相當容易上手,可說是相當普遍的一項量測儀器。 在現有的以DBB鑑別旋轉軸幾何誤差的方法中,是在不考慮熱變形誤差、線性軸幾何誤差,或在線性軸幾何誤差已經補償好的情況下,利用齊次座標轉換矩陣(Homogeneous Transformation Matrix, HTM)直接針對旋轉軸建立DBB隨旋轉軸運動之幾何誤差模型,再進行量測並求解,而且量測路徑數量也較多,而本研究則是在相同基本假設下,針對永進機械的搖籃式(AC Type)五軸工具機(NFX-500A),利用HTM建立包含旋轉軸幾何誤差之整機幾何誤差模型,找出總和誤差與旋轉軸幾何誤差之關係式,再以最小平方法(Least Square Method)進行求解,而且量測路徑數量較少。 本研究的鑑別方法目前僅適用於搭載具有四軸或五軸同動功能之FANUC控制器,且機台構型必須為搖籃式(AC Type)五軸工具機。由實驗結果證實,經過三次量測、兩次鑑別即可使旋轉軸中心位置誤差降低45%以上,這顯示本研究鑑別方法之可行性。

並列摘要


Geometric error is one of the critical factors effects the accuracy of five-axis machine tools. The machining accuracy will be enhanced if the geometric error can be reduce. The thesis focused on establish a complete geometric error model that used to identified the error of rotary axis, and then collocation of three planned measure path, NC codes and standard operating procedures to measure the deviations in the X, Y and Z directions of rotary axis motion to identified the error of rotary axis. The deviations in the X, Y and Z directions of rotary axis motion we call it composite error. The price of measuring instrument that can measure the geometric error of five-axis machine tools are more expensive than one million. DBB is much cheaper by comparison with the other measuring instruments. Moreover, DBB has been a standard equipment in machine tool manufacturers, and is easy to use. Most of existing methods using DBB to identify the error of rotary axis are not considered thermal deformation and error of liner axis. These methods modeled the geometric error model of DBB by homogeneous transformation matrix (HTM).Besides, the number of the measure paths is much more. In our research, the basic assumption is the same, we focus on table-tilting-type machine tools (NFX-500A) of YCM company and that using HTM build the geometric error model of complete machine to find the relationship between composite error and the error of liner axis. Finally, using less measure paths, and solving the error of rotary axis by using least square method. The identify method of this study currently only available for devices with a four-axis or five-axis machining functions with the FANUC controller and machine configuration must be table-tilting-type (AC type) machine tools. The experimental results show that the center location error of rotary axis can be reduce by within three times measurement and two time identify. That means that this identify method will be concrete and feasible.

參考文獻


[29] 陳志安, “五軸CNC工具機動態誤差與幾何誤差之誤差分析與模擬”, 國立虎尾科技大學機械與機電工程研究所, 2010.
[28] 李俊德, “五軸工具機幾何誤差量測”, 國立交通大學工學院精密與自動化工程學程碩士論文, 2011.
[30] 陳佳彥, “五軸誤差量測之路徑規劃與幾何誤差分析”, 國立虎尾科技大學機械設計工程研究所碩士論文, 2012.
[31] 侯志龍, “微放電加工機製程誤差與機台空間誤差之判認與補償”, 國立成功大學機械工程學系碩士論文, 2007.
[32] 盧盈辰, “反覆學習控制與工具機空間誤差補償之應用”, 國立臺北科技大學機電整合研究所碩士論文, 2014.

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