抄録
This study has proposed a new coordinate measuring machine (CMM) based on a three-degree-of-freedom parallel manipulator. This report describes a kinematic calibration method using one redundant passive kinematic chain including a prismatic joint with a linear scale unit. This passive limb connects the moving stage to the machine frame. Change in length of the passive limb is measured during traveling of the end-effector mounted on the moving stage. The least square method using Jacobian matrix corrects gradually 27 kinematic parameters so that the length errors of the passive limb are minimized. The above calculations have been repeated in numerical simulations. The length error approached a zero level. However, the error was not decreased to less than measurement error of the passive limb length. The calibration results has been verified by the length measurement simulation assuming the use of gauge blocks.
