Precise welding line detection of a hexahedron based on twisted motion of a scanning LRF

The precise welding line detection method based on twisted motion of a scanning laser range finder (LRF) is proposed for autonomous robotic welding of a hexahedron into a steel plate. For successful welding, the directions of the welding lines should be obtained precisely. For detecting welding line, more than two points on the welding line should be obtained. Thus, two points on the welding line are obtained based on the twisted motion of the scanning LRF. In this case, the feature point on the welding line is detected by applying the Hough transform into the sensor data of the LRF, taking the intrinsic characteristics of the sensor into consideration. Since the Hough transform is based on the voting mechanism, the sensor noise can be reduced. For verifying the feasibility of the proposed method, the simulation has been carried out with a commercial LRF model, UBG-04LX-F01 of Hokuyo Automatic Co., Ltd.