柔性三坐标测量臂几何误差修正

Geometric Error Correction for Portable Coordinate Measurement Arm

中文关键词:  柔性三坐标测量臂  误差修正  误差分析  几何误差  三坐标测量机

英文关键词:portable coordinate measuring arm(PCMA)  error correction  error analysis  geometric error  coordinate measuring machine(CMM)

中文摘要:

      柔性三坐标测量臂用于大尺寸工件的高精度检测及逆向工程,是现代制造业产品精度检测的重要设备。如何做好和完善测量臂误差的分析、检测和补偿,成为提高测量臂测量精度的重要问题。提出了用高精度正交三坐标测量机校准柔性三坐标测量臂关节误差的新方法。通过分析测量臂某一关节的所有几何误差,建立其数学模型;利用正交三坐标测量机和测量臂分别对30个标准球(均匀分布在一个圆上)进行点位测量,测出球心的标称值和实测值,建立了该关节几何误差补偿模型;对工件进行点位测量并进行误差补偿。实验结果表明,通过该误差补偿方法,其最大测量误差从0.04 mm降到了0.003mm,提高了柔性三坐标测量臂的测量精度,同时验证了该误差补偿方法的正确性和有效性。

英文摘要:

      Portable coordinate measuring arm (PCMA) is used to measure large-scale workpieces and in reverse engineering,etc. It is one of the important measurement devices to guarantee the manufacturing accuracy in modern industry.Error analysis,measurement and correctness are important in developing measurement precision of PCMA.The error model was built by analyzing geometric error for one of six joints,including encoder eccentric error and non-orthogonal rotational axis error.Aiming at building error compensating model,30 standard spheres were measured,which were fixed regularly in a circle by both coordinate measuring machine(CMM) and PCMA to build geometric error data.Coordinates of 30 spheres were measured by PCMA again and compensated.The maximum measuring error reduced from 0.04 mm to 0.003 mm after error correction.The experimental results have demonstrated that the measuring accuracy can be calibrated accurately and effectively and improved by using this technique to calibrate PCMA.