Mother-Crawler and Modular NDE-Boards for Robotics Scanning and Testing

INTRODUCTION Inspection in field conditions is labor intensive, demands great attention to details, subject to human errors and the reliability is limited. The interpretation of the data depends critically on the inspectors' experience, competence, attentiveness and meticulous dedication. For instance, rivet crack detection by eddy current is known to be a mundane and painstaking task, which can involve loss of the inspector concentration during a long inspection session. On the other hand, disassembly of structures and inspection in laboratory conditions is costly and in many cases it is not practical. These inspection limitations are hampering the growth in usage of composite structures for construction of aircraft since these structures are sensitive to impact damage that can occur at any time and any point over large areas. Also, there is an increasing need to perform rapid large area inspection of aging aircraft. For military aircraft, an additional constraint that may need to be accounted is the potential requirement to operate also at harsh, hostile and remote conditions (extreme temperature, battlefield, remote expertise, etc.) with minimum human interference. To overcome the limitations of standard NDE methods, reliable field inspection systems are being developed for rapid NDE of large and complex-shape structures. In recent years, various types of portable scanners were developed for rapid operation in field conditions using such NDE methods as visual, eddy currents, ultrasonics, shearography, and thermography. Recently, JPL developed a Multifunction Automated Crawling System (MACS) that can address the needs for robotic inspection. This crawler has an open architecture and allows emulating the success of the personal computer technology by forming a mother-crawler similar to the motherboard concept, where standard modular boards define the functionality of the crawler. The USA DoD and the Canadian Department of National Defense (DND) are now considering MACS as a baseline for robotic inspection of structures for corrosion detection