基于改进模拟退火算法的关节臂式坐标测量机参数辨识

结构参数误差是影响关节臂式坐标测量机精度的主要因素之一，精确辨识其结构参数可以有效地提高测量机的精度。建立基于Denavit-Hartenberg模型的六自由度关节臂式坐标测量机坐标变换方程，分析基于锥孔的参数辨识原理，提出一种改进的模拟退火算法用于测量机的结构参数辨识，该算法在接近最优解时将减小搜索范围以提高搜索效率和求解精度，并保留中间过程的最优解。以单点重复精度为目标函数，利用改进的模拟退火算法对研制的六自由度关节臂式坐标测量机的结构参数进行辨识。实验结果表明，经过参数辨识后，测量机的单点重复精度提高了7.87倍，长度测量精度提高了5.59倍。

Parameter identification based on modified annealing algorithm for articulated arm CMMs

Errors of structural parameters are one of the main factors causing uncertainty of articulated arm coordinate measuring machines (AACMM); therefore the accuracy of AACMMs can be improved efficiently by structural parameters identification. The homogeneous transformation equations of 6-DOF AACMMs were established based on Denavit-Hartenberg model. A method to identify structural parameters with a cone-shape hole was analyzed. A modified simulated annealing algorithm (MSAA) was presented to identify the structural parameters of the AACMMs. The MSAA can keep the best solution during search, and reduce the search range when the solution approaches the global minimum, which can improve the search efficiency and accuracy. The definition of single-point repeatability was deduced, and the method using single-point repeatability as the objective function to identify structural parameters of AACMMs base on the MSAA was presented. A 6-DOF AACMM was used to carry out experimental tests to evaluate the efficiency of the method presented, the results show that after identification the repeatability and length measurement accuracy of the AACMM are improved 7.87 and 5.59 times respectively.