Patent ID: 8653412

Claim:
An arc welding system comprising: a welding robot; a welding torch mounted to an arm fore end of the welding robot; a welding power supply connected to the welding torch and supplying welding power to a welding wire; and a controller for controlling the welding power supply, wherein the welding power supply includes: a welding current detection unit for detecting a welding current value of the welding wire and outputting a welding current value detection signal representing the welding current value; a welding power supply interface for receiving, from the controller, a welding power-supply control signal to control the welding power supply and a welding power-supply sync signal that is supplied as a sync signal to the welding power supply at intervals of certain time, receiving the welding current value detection signal from the welding current detection unit, and outputting to the controller, as a welding power-supply feedback signal, the welding current value detection signal obtained at the time of inputting of the welding power-supply sync signal; and a welding power supply output unit for outputting the welding power in accordance with the welding power-supply control signal input through the welding power supply interface, wherein the welding power supply controller includes: a controller interface connected to the welding power supply interface via a Controller Area Network (CAN) for receiving the welding power-supply feedback signal from the welding power supply, and outputting the welding power-supply control signal and the welding power-supply sync signal to the welding power supply in a frame that is transmitted and received at constant intervals; a servo amplifier connected to the welding robot for controlling driving of the welding robot in accordance with a robot control signal for controlling the welding robot, and outputting a robot feedback position signal representing a position of the welding torch at the time of inputting of a robot sync signal as a sync signal for the welding robot; and a robot welding power-supply control unit for generating the welding power-supply sync signal and the robot sync signal, outputting the welding power-supply sync signal and the welding power-supply control signal to the controller interface, detecting a position deviation of the welding torch from the welding power-supply feedback signal, which is the welding current value detection signal obtained at the time of inputting of the welding power-supply sync signal, and the robot feedback position signal, both input during arc welding, generating the robot control signal to correct the position deviation of the welding torch, and outputting the generated robot sync signal and robot control signal to the servo amplifier, and wherein the welding power supply and the controller are connected in a serial way and communicate with each other using digital signals.