ROBOT CONTROLLING SYSTEM

A robot control system comprises a hand movable along a plane according to position command data determined based on an absolute coordinate system arranged along the plane, and rotatable around an axis vertical to the plane according to angular command data determined with respect to a base axis of the absolute coordinate system for working a workpiece at a certain working point thereof with a certain angular position of the hand. Input means inputs working point data representative of the working point in terms of a local coordinate system arranged on the workpiece, angular position data representative of the angular position of the hand at the working point determined with respect to a base axis of the local coordinate system, and position data of the workpiece located along the plane in terms of the absolute coordinate. Calculation means calculates the linear and angular displacements of the local coordinate system relative to the absolute coordinate system according to the position data of the workpiece provided by the input means. First transformation means transforms the local working point data provided by the input means to the absolute position command data according to the calculated linear and angular displacements. Second transformation means transforms the local angular position data provided by the input means to the absolute angular command data according to the calculated angular displacement.