五軸工具機轉動軸之動態誤差量測分析

Measurement of Dynamic Errors of Rotary Axes in Five-axis CNC Machine Tools

王文中(Wen-Chung Wang) ； 雷衛台(Wei-Tai Lei)

《中華民國振動與噪音工程學會論文集》 2014 (2014/06) Pp. 291-295

摘要

雙球桿量測儀為量測CNC工具機線性軸動態誤差最常用的量測裝置，量測時CNC工具機以NC程式控制走一圓形路徑，以DBB內之LVDT量測循圓時工具機出現的幾何誤差，包括直角度、背隙、節距誤差；驅動動態誤差如伺服增益匹配、黏滑效應（stick-slip）、失位(lost-motion)誤差，及機器振動狀況等，並可配合各種參數補償技術，調整CNC控制器中各軸控制參數。雙球桿量測儀使用方法簡便，是CNC工具機製造廠的基本標準量測設備，循圓量測方法應用於CNC三軸與五軸工具機中之線性軸的量測相當成熟，針對CNC五軸工具機中之轉動軸，目前無法以此量具進行誤差量測。在循圓運動量測時可檢測出工具機進給機構中滾珠螺桿的振動現象，針對線性軸使用雙球桿進行循圓量測時，兩線性軸之驅動訊號為單頻訊號，於後續針對機器振動狀況分析時較容易，本文提出針對五軸工具機中轉動軸之雙球桿循圓誤差量測方法，並分析其驅動訊號之頻譜，以探討對機器振動之影響。

關鍵字

五軸工具機 ； 雙球桿 ； 轉動軸循圓量測

並列摘要

Double ballbar (DBB) is widely used in dynamic errors inspection for linear axes of CNC machine tools. Dynamic errors such as gain mismatch, stick-slip, lost motion, drive vibration etc. can be detected by executing a measuring circular path. The measured results are used to tune the servo control parameters and to enable compensation functions in CNC controller. This article expands the DBB measurement method to rotary axes in five-axis CNC machine tools. The DBB test can inspect the vibration movement resulted from the ball screw of the feed drive system .In DBB test for linear axes, the driving signals of both linear axes are of single frequency. In this article, new DBB methods are proposed to measure dynamic errors of rotary axes in five-axis CNC machine tools. The frequency spectrum of the driving signals is analyzed and their effects on the DBB test are discussed.

並列關鍵字

Five-Axis Machine Tools ； Double Ballbar ； Rotary Axis ； Dynamic Errors