Visual inspection and nondestructive evaluation (NDE) of natural gas distribution mains is an important future maintenance cost-planning step for the nation's gas utilities. These data need to be gathered at an affordable cost with the fewest excavations and maximum linear feet inspected for each deployment, with minimal to no disruption in service. Current methods (sniffing, direct assessment) are either postleak reactive or too unreliable to offer a viable and Department of Transportation-acceptable approach as a whole. Toward achieving the above goal, a consortium of federal and commercial sponsors funded the development of Explorer TM . Explorer TM is a long-range, untethered, self-powered, and wirelessly controlled modular inspection robot for the visual inspection and NDE of 6-and 8-in. natural gas distribution pipelines/mains. The robot is launched into the pipeline under live (pressurized flow) conditions and can negotiate diameter changes, 45-and 90-deg bends and tees, as well as inclined and vertical sections of the piping network. The modular design of the system allows it to be expanded to include additional inspection and/or repair tools. The range of the robot is an order of magnitude higher (thousands of feet) than present state-of-the-art inspection systems and will improve the way gas utilities maintain and manage their systems. Two prototypes, Explorer-I and -II (X-I and X-II), were developed and field-tested over a 3-year period. X-I is capable of visual inspection only and was field-tested in 2004 and 2005. The next-generation X-II, capable of visual and NDE inspection [remote field eddy current (RFEC) and magnetic flux leakage (MFL)] was developed thereafter and had field trials in 2006 and late 2007. It was successfully deployed into low-pressure (<125 psig) and high-pressure (>500 psig) distribution and transmission natural gas mains, with multi-1,000-ft inspection runs under live conditions from a single excavation. This paper will describe the overall engineering design and functionality of the Explorer TM family of robots, as well as the results of the field trials for both platforms. It will highlight the importance of the various design and safety features of the in-pipe crawler and showcase the value of data types and position-tagged visual/NDE data collected in working pipelines under live flow conditions. C

No abstract

No abstract

I. ABSTRACTUrban settings represent a challenging environment for teleoperated and autonomous robot systems. We present a new design for a highly terrainable robot system, detailing the major mechanical, electrical and control systems. The Pandora robot system is a tracked robot system with selfcontained computing, power and wireless communications systems. A sensor suite including stereoscopic and panospheric cameras, light-stripers and acoustic sonarring(s) allow the system to operate autonomously. Individually adjustable track-modules give Pandora extreme mobility in natural (vegetation, soils) and manmade (roads, steps) outdoor environments as well as indoor arenas (sewers, staircases, etc.). Locomotion was shown successfully over various extreme terrains, including reconfiguration to best suit the terrain and enable future sensor-supported autonomous operations. II. INTRODUCTIONThe need for robotic scouts, pointmen or recon-drones in urban settings, come from the facts that military operations in urban environments are highly dangerous, timeconsuming and incur the largest percentage of casualties in modern engagements. The use of a robotic system with sufficient sensory capability to detect opposing elements, sufficient autonomy to not distract moving unit operators, and sufficient locomotion and power-autonomy to access any area over long-duration missions would be a great asset to the U.S. ground forces. Since these kinds of systems do not exist at this time, and their best mission profiles and capabilities have not been evaluated, it became important to establish a program at DARPA that would pursue the development and evaluation of prototype systems in realistic scenarios to better understand the utility of robotics in urban operations.Current urban operations, based on our limited introduction and short exposure to a training mission at the MOUT training facility at Camp Pendleton in CA, can be termed highly intricate (see Figure 1). The goal is to advance through the urban setting, without exposing oneself in a lethal situation, thereby flushing opposing forces from strongholds in the setting, while securing the area for non-combatants and behind-the-lines operations. Typically this involves a three-man force advancing under any cover through the urban terrain, trying to detect any opposing forces in the large number of possible hiding places (sewers, roofs, doors, walls, etc.) so as to overwhelm or flush them out in the process of securing the urban setting a building/block/street/neighborhood at a time. The key during this operation is to get as much data to the team for them to evaluate the potential for threat, whether it is in the sewers, higher-up floors (snipers), behind walls/vehicles, etc. -the ability to gather and process reconnaissance data without exposing oneself in a potentially lethal manner is thus highly desirable. The remote reconnaissance system would at the same time need to be able to proceed over terrain amenable to humans, progress at a human-equivalent speed, carry capable sen...

No abstract