亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

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 15.8754mm was used to test the accuracy of the calibration parameters. The experimental results were as follows: a5=78.312mm, a7=25.962mm, b3=747.489mm, b5=531.880mm, b7=178.383mm, d7=176.484mm. Through experiments, the relative error of the standard ball diameter was 0.3836%. 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.