中文摘要：

采用对称点法对关节臂式坐标测量机的各参数进行标定。该标定方法把各参数分离，使标定过程更简单。首先，在D—H参数建模法的基础上，利用基于准球坐标系的建模方法，建立了关节臂式坐标测量机的数学模型，使关节间各个参数正交，进而推导了运动学方程。借助设计的固紧装置，在ROMER Infinite2．0型关节臂式坐标测量机上运用该方法进行了标定实验，得出了坐标测量机的结构参数，验证了参数标定方法的可行性和实验结果的准确性，为进一步提高关节臂式坐标测量机的测量精度奠定了基础。

英文摘要：

The parameters calibration of the articulated arm coordinate measuring machine is the key to ensure the working accuracy of the measuring machine. The disadvantages in the process of the parameters calibration for articulated arm coordinate measuring machine are as follows： complex calibration method and algorithms, poor operability and costly calibration tools production. To solve this problem, the symmetry point method was used to calibrate the parameters of the articulated arm coordinate measuring machine. This calibration method can separate the parameters and make the calibration process more simply. Firstly, the mathematical model of the articulated arm coordinate measuring machine was established based on the quasi spherical coordinate system. The quasi spherical coordinate system was proposed based on the D - H method. This mathematical model can be used to make the parameters orthogonal between the joints. Then, the kinematics equation was deduced. The fixing device was designed according to the requirement of experiment. The experiment was performed on the ROMER Infinite 2.0 articulated arm coordinate measuring machine. The standard ball with a diameter of 15. 875 4 mm was used to test the accuracy of the calibration parameters. The experimental results were as follows： a5 =78. 312 mm, a7 =25. 962 mm, b3 =747. 489 mm, b5 =531. 880 mm, b7 = 178. 383 mm, d7 = 176. 484 mm. Through experiments, the relative error of the standard ball diameter was 0. 383 6%. The results of the experiments showed that this symmetry point method was feasibility and the experimental results were accurate. It establishes the foundation for improving the measuring accuracy of the articulated arm coordinate measuring machine.