METHOD FOR CONTROLLING INDUSTRIAL ROBOT

PURPOSE:To shorten the welding time by teaching an optional place of a work as a regulating point of electrode wire extension and using a corrected value by sensing of the work to correct said regulating point of the electrode wire extension and carrying out regulating work at a place close to a welding starting point. CONSTITUTION:An electrode 4a is brought into a torch 4 and a changeover switch is changed over to a power source for detection. The virtual tip P of the torch 4 falls and moves so that it is located at the regulating point P7' of the electrode wire extension after being corrected. Hereby, the distance between the chip tip of the torch 4 and the surface of a horizontal plate W1a' of the work is exactly coincident with the regular electrode wire extension L0. Continuously, the electrode 4a is fed and again projected toward the horizontal plate 1a' from the chip tip and the tip approaches the horizontal plate 1a' and discharges electricity to detect the surface of the horizontal plate W1a'. A computer 8 receives an electrification signal from an electrified state detection output circuit and the electrode 4a returns to the original intermediate shunting position P6. The electrode tip of the torch 4 is coincident with the position P6 and the electrode wire extension is in a state regulated to be equal to the regular extension L0.