Method and apparatus for determining the correct tool dimensions for a

Abstract

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.