CAJ | 학술논문

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.本文基于Denavit-Hartenberg模型建立了六自由度关节臂式坐标测量机坐标变换方程,分析了基于锥孔的参数辨识原理,提出了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.
결구삼수오차시영향관절비식좌표측량궤정도적주요인소지일,정학변식기결구삼수가이유효지제고측량궤적정도.본문기우Denavit-Hartenberg모형건립료륙자유도관절비식좌표측량궤좌표변환방정,분석료기우추공적삼수변식원리,제출료일충개진적모의퇴화산법용우측량궤적결구삼수변식.해산법재접근최우해시장감소수색범위이제고수색효솔화구해정도,병보류중간과정적최우해.이단점중복정도위목표함수,이용개진적모의퇴화산법대연제적륙자유도관절비식좌표측량궤적결구삼수진행변식.실험결과표명,경과삼수변식후,측량궤적단점중복정도제고료7.87배,장도측량정도제고료5.59배.
Errors of structural parameters are one of the main factors causing uncertainty of Articulated Arm Coordinate Measuring Machines (AACMM),however,the accuracy of AACMMs can be improved efficiently by identifying structural parameters accurately.In this paper,the homogeneous transformation equations of 6-DOF AACMMs were established based on Denavit-Hartenberg model and a method to identify structural parameters with a cone-shape hole was analyzed.Then,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 can reduce the search range when the solution approaches to the global minimum,which improves the search efficiency and accuracy.The definition of single-point repeatability was deduced,and the structural parameters of AACMMs were identified by using single-point repeatability as the objective function based on the MSAA.A 6-DOF AACMM was used to carry out experimental tests to evaluate the efficiency of the presented method,the single-point results show that after identification,the repeatability and length measure-ment accuracy of the AACMM are improved by 7.87 and 5.59 times respectively.