Fault-tolerant weld line detection for automatic inspection of storage tanks based on distance and visual information fusion

Quality control, cost reduction and above all, human and environmental safety are great reasons that stimulate the investments in technologies like automatic inspection. The automatic inspection of weld lines in storage tanks is of special interest, due to the fact that such tanks are currently used to store harmful products. For a reliable inspection it is necessary to accurate detect the weld line position. In this paper the development of a system to perform weld line detection in storage tanks is proposed. Two redundant systems, based on different physical principles, distance and visual information, are implemented and tested. Such systems make use of a fault-tolerant estimation process based on the α-β filter. Finally, the outputs of the two redundant systems are fused, aiming at to increase the confidence and performance of the system.