|Budget Amount *help
¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1996 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1995 : ¥1,600,000 (Direct Cost : ¥1,600,000)
In last year, a basic system for recognizing welding line by visual sensing was constructed. In this year, a robust control system for recognizing and tracking the welding line in butt welding of thin steel plates was constructed. In this system, the recognition of the welding line was performed by applying the image data acquired by CCD camera to artificial neural network (N.N.) and position and shape of the welding line was detected. Furthermore, in order to obtain sound weld regardless change of welding conditions, such as groove shape, gap of groove and so on, system to diagnose the welding phenomena during welding and to control welding conditions were constructed.
Main results obtained are summarized as follows.
(1) Preprocessing of image : Before inputting image data into N.N., smoothing was applied to the image using 2-D space filter to eliminate noise. Then the LOG filter was applied to it in order to enhance the edge of the welding line image and the binarisation was applied. T
he image data obtained were used as the input data to N.N..
(2) Tracking experiments by the developed system : Experiments for recognizing welding lines of base metals which have several surface conditions, type of material, groove shape, type of groove, lighting conditions and arc conditions were performed, and the effectiveness of the recognizing system constructed was confirmed. Furthermore, butt welding experiments of mild steel plates were performed and effectiveness of the system to automatic welding was confirmed.
(3) Monitoring of mlten pool : In order to realize real-time control of welding condition and obtain a sound weld, a monitoring system of molten pool in arc welding was constructed. As the relationship between the molten pool shape and penetration of weld has intimate relationship, if the shape of the molten pool can control, the sound weld with optimum penetration may be obtained. In this study a monitoring system and arc current control system were combined and a basic welding control system was constructed. Less