A method to generate a high-continuity thickness measuring path has been proposed in our own developed automatic system using laser displacement sensors and an industrial robot to measure and evaluate a free curved plate thickness. Besides the system generates the thickness measuring path on the basis of the point cloud data representing a workpiece shape, in this method, a quaternion is used to represent a change in the measuring posture with squad which is an interpolation algorithm. This paper presents a new method to determine the positions and the postures of the representative points for continuous interpolation. These positions and the postures are determined using 3D Configuration space(C-Space) consisting three parameters for representing the measuring posture. For details, the measurable postures are mapped in the C-Space on each measuring point. Then, the positions of the representative points are determined using a local maximum value of the distance between centroid coordinate of the measurable postures in adjacent points. Moreover, the postures of them are determined using the common postures of adjacent points or the distance from the origin of the C-Space. The continuity of the measuring path is evaluated from the change in the joint angle of the robot. Specifically, angular acceleration of the joint angle is used to evaluate for stabilization of the high-speed robot motion. The experimental result shows that the angular acceleration of the robot joint in generated path is smaller than that of the path generated by a conventional method.
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