Robotic Inspection of Crude Oil Carrier TanksEPA Contract Number: 68D10064
Title: Robotic Inspection of Crude Oil Carrier Tanks
Investigators: Churchill, Russell J.
Small Business: American Research Corporation of Virginia
EPA Contact: Manager, SBIR Program
Project Period: September 1, 1991 through February 1, 1993
Project Amount: $150,000
RFA: Small Business Innovation Research (SBIR) - Phase II (1991) Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:The inspection of very large crude carriers (VLCC) for structural reliability is a critical environment concern. These large vessels transport crude oil in such quantifies that the consequence of an oil spill due to a broken weld would be disastrous. Existing techniques for inspecting VLCC tanks require that the ship be taken out of service and brought to a repair facility where the tanks must be drained and their inner surfaces cleaned before inspection can begin. To reduce the time and cost involved in inspections and to identify damaged regions for effective maintenance, a robotic inspection system will be developed incorporating magnetic eddy current technology and video camera in- spection. The program is innovative in providing a time sequence of nondestructive characterization images which can be used to identify growing cracks in VLCC structures. Phase I results show that frequency mixing can enhance the signal-to-noise ratio of fatigue cracks in welded steel, while cross-correlation techniques can be used to align scan images provide a history of damage development
The Phase II technical objectives include development of eddy current probes, design of remotely operated vehicle correlation techniques for detection of crack growth, and optimization of a proof-of-concept system for Phase III commercialization. Detection of localized damage will be accomplished by segmenting the images into smaller cross- correlation regions for improved resolution. The proposed system will permit more frequent inspections and increase the safety and reliability of carriers operating under ex- tended service.