Automatic inspection of gas pipeline welding defects using an expert vision system

Automatic inspection of welded gas pipelines is desirable because human inspectors are not always consistent evaluators. In addition, automatic inspection decreases the cost of inspection process and improves the inspection quality. In this paper, an expert vision system for automatic inspection of gas pipeline welding defects from radiographic films is presented. The proposed system has been established in the Metrology lab, Mansoura University, Faculty of Engineering. The software, named AutoWDI, is fully written in lab using Microsoft Visual C+ + and is ready to run on any Windows environment. The proposed vision system is used to capture images for the radiographic films then applies various image processing and computer vision algorithms to recognize the defects and to make acceptance decisions according to international standards. The expert system is based on a knowledge base, which was gathered from specialists, textbooks and international standards. The proposed system is capable of identifying and testing the main types of welding defects (11 defects) in gas pipelines welded by shielded metal arc welding. (C) 2003 Elsevier Ltd. All rights reserved.