三坐标精度测量机的工作原理和机械结构

兑水

徐刚 费业泰 李光柯
合肥工业大学,合肥市230009
摘　要:开发了一种基于空间一维球列对称联系组合定标法的手提式三坐标精度测量机，其系统由球列板、滑轨、支架、底座以及伺服驱动系统、电气控制部分和数据处理软件组成。在准确已知球列上任意一对球心距偏差的条件下，可得到整个球列各球心距偏差，再以该球列各球心形成的标准点列与测量机空间的点列进行对称组合比较测量，按最小二乘原理处理测量值，可求得被测三坐标测量机被测空间点的误差，再按通用的数据分解方法即可得到坐标测量机几何结构的21项误差。利用全组合对称联系使一维球列校正精度达到高精度水平，同时由于球列可在该校正装置的滑轨上移动，使该装置可校正范围比球列本身的标准长度增加数倍。仅需在校正前对球板上的一个球心距进行检测标定并作为标准量，即可通过一次测量同时确定事先均未知的一维球列精度和三坐标测量机精度，使校正过程易于实现。此外，校正装置无需严格按国家标准量值传递定期校正，而可由使用单位利用已有标准量和简单装置在使用前进行实时检测标定，因此它对校正装置的长期稳定性无严格要求，可降低对校正装置的设计与制造要求。[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