Hideaki Ishii

Load Transfer Analysis Using Indexes U* and U** for Truck Cab Structures in Initial Phase of Frontal Collision

A new index U* which represents load paths in structures was applied to a truck cab under collision. After obtaining the deformed body by a dynamic crash simulation, U* for the extracted deformed body was statically calculated. The distributions of U* were compared with the values of U** obtained in our previous report. The U* and U** distributions show almost the same pattern. However, the absolute value of U* is larger than U** by about 1.6 times. The difference is inevitable because of the difference in their definitions. The concepts of U*sum and its histogram were used to express the effectiveness of the load transfer. Using these expressions, it was shown that the main member of this cab transfers the loading effectively.

Detection and Automatic Tracking of Butt Weld Line by Autonomous Mobile Robot for Pipe Welding.

An Autonomous mobile robot system with a visual sensor for automatic pipe welding was constructed. The robot developed can move along a pipe autonomously and detect a weld line to be welded by means of its visual sensor. The robot can confirm automatically whether the line detected is a weld line to be welded or not. Moreover, the tracking of the weld line at a constant welding speed and butt welding of the pipes are executed automatically. Generally, the recognition of a weld line is difficult in welding because of the brightness of the welding arc. In this system, in order to recognize it stably, a special lighting system and some image-processing methods are applied. The effectiveness of the system constructed was confirmed through experiments on automatic weld line tracking.