Cincinnati Milacron Inc.

Keith R Wehmeyer

Ronald L Tarvin

Gregory Webb

A method and apparatus by which correct tool dimensions for a three dimensional tool mounted on a manipulator can be determined. The manipulator operator inputs initial values for the tool dimensions into the manipulator control in the teach mode. Having established a target point within the manipulator's working volume, the operator, by means of teach pendant, causes the tool center point to approach and touch the target point from four different directions, at least one of which is noncoplanar with respect to the other three. For each approach point coordinates X, Y, Z, D, E, R are entered into the control. The control thereafter executes an analytical procedure including a major iteration loop which calculates the coordinates of the target point. In a first minor iteration loop within the major iteration loop updated tool dimensions are derived. In a second minor iteration loop within the major iteration loop new coordinates for the tool center point approach points are calculated. The differences between the average of the calculated coordinates of the target point and the average of the calculated coordinates of the approach points are determined. If the differences fall within operator determined limits the tool dimensions calculated in the first minor iteration loop are used. If not, the major iteration loop is repeated using the calculated values the tool dimensions and approach point coordinates of the previous iteration until they do, or until a predetermined number of iterations has been performed, whereupon an error signal is displayed.

Method and apparatus for determining the correct tool dimensions for a

A three-dimensional vision seam tracking method and apparatus for controlling the motion of the center point of a tool mounted on a manipulator. The manipulator is provided with a control to operate the manipulator members to move the tool center point at programmed velocities along a programmed path corresponding to the seam. The manipulator is provided with a vision system including a laser scanner/camera head mounted ahead of the function element. The control is programmed with dynamically varying orientation angles to control the orientation of the tool during seam tracking. The laser scanner/camera head scans the seam at predetermined time intervals. A set of coordinates for the center point of the seam in a coordinate system relative to the camera is provided for each scan. The sets of camera coordinates are transformed to the coordinate system of the manipulator using transformation matrices employing the orientation angles in effect at the time of the scan for the set of camera coordinates being transformed. The transformed coordinates are stored in a FIFO buffer until needed. The seam tracking routine of the manipulator control removes FIFO entries at some later time and alters the manipulator's programmed path to move the tool center point along the seam.

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Cincinnati, OH, United States of America

Keith R Wehmeyer