用蚁群算法求解关节式坐标测量机的最佳测量区

Optimal measurement area of articulated coordinate measuring machine calculated by ant colony algorithm

本文提出了一种求解最佳测量区的方法,以进一步提高关节式坐标测量机的测量精度。首先,根据关节式坐标测量机的测量模型,建立了基于圆编码器测角误差的关节式坐标测量机误差模型。利用蒙特卡洛理论得到6个关节转角的随机数,采用数值法仿真分析测量机的测量空间。然后将包含测量空间的一立方体区域等间隔切割成343个小立方体区域,采用蚁群算法确定每个小区域由于圆编码器误差所引起的最大测量误差。最后,通过比较找到其中最大测量误差最小的区域,即为最佳测量区。研究结果表明,对于所研究的关节式坐标测量机,各个小区域的最大误差为0.069 9~0.189 6mm,其中最小值为0.069 9mm的区域为-100mm≤x≤100mm,-100mm≤y≤100mm,400mm≤z≤600mm。采用本文方法确定的最佳测量区在测量空间内为一个立方体区域,故在最佳测量区进行较高精度的测量具有实用性和可操作性。

A method to solve the optimal measurement zone was proposed to improve the measurement accuracy of the articulated coordinate measuring machine.According to the measurement model of the articulated coordinate measuring machine,the error model of the articulated coordinate measuring machine was established on the basis of angle measurement error of the circle grating encoder.6random numbers of the articulation rotation angle could be obtained by taking advantages of Monte Carlo theory;and the measurement space of the measuring machine could be simulated by using the numerical method.Then,the cube region which include measurement space were divided into 343 small cube regions and the ant colony algorithm was used to determine the maximum measuring error of each region caused by the error of the circle grating encoder.Finally,minimum region of the maximum measuring error was found and as the optimal measurement zone by comparison.The result of the research isshown that in terms of the researched articulated coordinate measuring machine,the scope of the maximum error for each small region is from 0.069 9mm to 0.189 6mm.Among them the region of the minimum value which is 0.069 9mm is-100 mm ≤x≤100mm,-100mm≤y≤100mm,400mm≤z≤600mm.The optimal measurement zone determined by proposed method is a cube region within the measurement space,which make it have the practicability and operability to conduct higher-accuracy measurement in the optimal measurement zone.