Patent attributes
An edge extraction unit extracts an edge image from a photographed image obtained by photographing a product with a camera. A constant edge acquisition unit acquires, as a constant edge image, an edge image in a constant surface where a positional deviation does not occur with respect to a welding point set by a processing program, the acquired image belonging to the extracted edge image. A correction amount acquisition unit performs pattern-matching between a master constant edge image and a workpiece edge image, which are acquired by the constant edge acquisition unit, and acquires a deviation amount between both thereof as a correction amount with respect to the welding point. A processing program correction unit corrects the welding point by the correction amount, and generates a corrected processing program for welding the workpiece. A welding robot welds the workpiece based on the corrected processing program.