关节臂式坐标测量机测量力误差分析及补偿

Error analysis and compensation of the measuring force of the articulated arm coordinate measuring machine

针对接触测量力对关节臂式坐标测量机(AACMM)测量精度的影响展开研究。对测量力引起的长度测量误差进行理论和实验分析,得到测头与被测件的局部变形、测杆的弯曲变形是影响关节臂式坐标测量机测头精度的主要因素。建立了关节臂式坐标测量机测头与被测件的局部变形、测杆的弯曲变形的数学模型,并对测量结果进行了测量力误差补偿。实验结果研究表明,测量力引起的误差对接触式关节臂式坐标测量机测量精度影响很大。通过本研究成果,可在很大程度上补偿测量力引起的误差:平均长度测量误差降低82%左右,最大误差降低约47μm,有效地提高了关节臂式坐标测量机的测量精度。

Measuring accuracy of AACMM based on measuring force is focused in this work. The error of length measurement caused by measuring force is analyzed theoretically and experimentally. The local deformation of the probe and the measured object and the bending deformation of the measuring rod are the main factors affecting the accuracy of AACMM. The mathematical models of the local deformation and the bending deformation of the rod are established, with which the measuring results compensated with force error. Results show the error caused by measuring force can be compensated to a great extent： the average length measurement error is reduced about 82% , the maximum error is reduced by about 47um, which effectively improves the precision of AACCM.