三坐標精度測量機的工作原理和機械結構

徐剛 費業泰 李光柯
合肥工業大學,合肥市230009
摘　要:開發了一種基于空間一維球列對稱聯系組合定標法的手提式三坐標精度測量機，其系統由球列板、滑軌、支架、底座以及伺服驅動系統、電氣控制部分和數據處理軟件組成。在準確已知球列上任意一對球心距偏差的條件下，可得到整個球列各球心距偏差，再以該球列各球心形成的標準點列與測量機空間的點列進行對稱組合比較測量，按最小二乘原理處理測量值，可求得被測三坐標測量機被測空間點的誤差，再按通用的數據分解方法即可得到坐標測量機幾何結構的21項誤差。利用全組合對稱聯系使一維球列校正精度達到高精度水平，同時由于球列可在該校正裝置的滑軌上移動，使該裝置可校正范圍比球列本身的標準長度增加數倍。僅需在校正前對球板上的一個球心距進行檢測標定并作為標準量，即可通過一次測量同時確定事先均未知的一維球列精度和三坐標測量機精度，使校正過程易于實現。此外，校正裝置無需嚴格按國家標準量值傳遞定期校正，而可由使用單位利用已有標準量和簡單裝置在使用前進行實時檢測標定，因此它對校正裝置的長期穩定性無嚴格要求，可降低對校正裝置的設計與制造要求。[著者文摘]


Principle and Mechanical Structure of Accuracy Checking Device for CMMsXu Gang, Fei Yetai ,Li GuangkeXu Gang, Fei Yetai ,Li GuangkeAbstract:A portable accuracy calibrating instrument for CMMs are developed based on the combination calibration method with symmetric connection of one dimensional ball row. The system consists of a flat with global holes, a sliding track, a bracket, a foundation, a servo-drive system and electric control, as well as data - processing software. Based on the knowing of any interval＇s deviation of the ball row, the row intervals are contrasted with the coordinate intervals using symmetrically connected method. Then the error of the point in the space of CMM can be calculated by processing the measuring values with the least square principle. By using this method called combination calibration with symmetric connection of one dimensional ball row, the checking accuracy of one dimensional ball row can reach a high level and the checking range can be largely increased. Based on the calibration of one interval of ball row which is regarded as the standard value, the accuracy of one dimensional ball row and the accuracy of CMM which is unknown before checking can be obtained after a whole measuring process. What＇ s more, the checking device needn＇ t be calibrated periodically according to the national standard value transmission, but it needs to be calibrated by using units with simple device and the standard value that they have. So this method doesn＇ t require tbe stability of the checking device, and it will also be easier to design and manufacture the checking device.[著者文摘]

Key words:one dimensional ball row, symmetric connection, ＂combination calibration method, CMM, accuracy correction