Structural Parameter Identification for Articulated Arm Coordinate Measuring Machines

Errors of structural parameters are the most important factors causing uncertainty of articulated arm coordinate measuring machines (AACMMs). Therefore these parameters must be identified to insure the accuracy of AACMMs. The kinematic model of six degree of freedom (6-DOF) AACMMs was established, and the structural parameters influencing the accuracy of AACMMs were achieved through analysis. A method to acquire data for identification with a cone-shape hole was presented. With single-point repeatability as the objective function, a modified simulated annealing algorithm (MSAA) was presented to identify structural parameters. A 6-DOF AACMM was used to carry out experimental tests in order to evaluate the efficiency of the MSAA, showing that after identification the repeatability and length measuring accuracy are improved greatly.