document: The development of a mobile manipulator imaging system for bridge crack inspection A mobile manipulator imaging system is developed for the automation of bridge crack inspection . During bridge safety inspections , an eyesight inspection is made for preliminary evaluation and screening before a more precise inspection . The inspection for cracks is an important part of the preliminary evaluation . Currently , the inspectors must stand on the platform of a bridge inspection vehicle or a temporarily erected scaffolding to examine the underside of a bridge . However , such a procedure is risky . To help automate the bridge crack inspection process , we installed two CCD cameras and a four-axis manipulator system on a mobile vehicle . The parallel cameras are used to detect cracks . The manipulator system is equipped with binocular charge coupled devices -LRB- CCD -RRB- for examining structures that may not be accessible to the eye . The system also reduces the danger of accidents to the human inspectors . The manipulator system consists of four arms . Balance weights are placed at the ends of arms 2 and 4 , respectively , to maintain the center of gravity during operation . Mechanically , arms 2 and 4 can revolve smoothly . Experiments indicated that the system could be useful for bridge crack inspections
doc_bio_tags: O O O O B I B I O B I I O B I B I O O O O B O B I I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O