Inside Unmanned Systems

AUG-SEP 2018

Inside Unmanned Systems provides actionable business intelligence to decision-makers and influencers operating within the global UAS community. Features include analysis of key technologies, policy/regulatory developments and new product design.

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AIR HAZARD LOCATION 62   August/September 2018 unmanned systems inside In addition, "the workers have to wear suits w ith visors and closed breathing systems," Whittaker said. "Until you've operated in those things, it's hard to describe the challenges with visibility and manipulation with gloves you face, and depending on the weather conditions, how hot and confining they are." Instead, RadPiper will find these radioactive deposits by traveling inside the pipes. "By taking measurements directly inside the pipe, all these considerations regarding attenuation are not an issue," Rimando said. "And RadPiper can scan as it moves continuously without stopping. The rea- son people have to stop when scanning from the outside is because they have to wait for measure- ments to come in since a pipe can weaken signals traveling through it, but by scanning within the pipe, RadPiper avoids that concern. It is much more efficient." RadPiper is a tetherless robot designed to move on a pair of f lexible tracks like a miniature tank or bulldozer. "Going tetherless gives the robot a lot of freedom to operate," Rimando said. Tethered robots have a decades-long history of use in nuclear facilities. Tethers can offer virtu- ally unlimited power as well as wires for commu- nications. And a tether can serve as a leash to help winch a robot back if necessary. However, "in the types of environments we are sending robots, one concern is that the tether can be severed or even simply disconnected, and then that's a real pickle—you'll lose communi- cations, you'll lose control and you'll lose your recovery capabilities," Rimando said. "Also, in areas with radioactive contamination, the teth- ers can disturb those contaminants and spread them, and when you're dealing with fissile mate- rials, you don't want that material to accumulate and raise concerns it might go critical. Advances in robotics, batteries, wireless communications and microprocessors now help give tetherless systems a lot of capabilities." RadPiper is about 45 inches long by 17 inches wide and 21 inches tall, and weighs approximately 180 lbs. Sensors in its tracks help measure the distance it has traveled, and an inertial measure- ment unit (IMU) and laser rangefinder help the robot stay upright and keep track of its position. RadPiper is equipped with a fanless embedded Intel quad-core i7 system as its main computer. The robot is equipped with two LiDAR range- finders, a fisheye camera, eight white ultraviolet LEDs to help it see obstructions such as closed valves, and eight ultraviolet LEDs that can make uranium-loaded deposits visibly f luoresce. After scanning a stretch of pipe, RadPiper automati- cally returns to its launch point. The robot's Canberra Osprey radiation detec- tor uses a standard sodium iodide sensor to count gamma rays. The sensor is positioned between two large lead disks that block gamma rays from radioactive deposits that may lie beyond the one- foot section of pipe the sensor is scanning at any given time. "These lead disks let you know what exactly the robot measured from a given slice of the pipe, without having to worry about interfer- ence from elsewhere in the pipe," Whittaker said. A USB data drive is used to store data from each run and transfer it to a computer. Analyzing the data is an automated process that takes a few minutes on a laptop, and the results include a chart of deposits plotted with respect to distance inside the pipe, as well as visual imagery. A pair of lithium iron magnesium phosphate battery modules can help the robot operate for five hours and a maximum total round trip of 600 feet. Battery charging time is typically two hours, allowing for rapid turnaround. To help prevent nuclear waste from cling- ing onto RadPiper, the robot's contours are as round as possible, Rimando said. After RadPiper emerges from a pipe, researchers wipe off any contamination on the robot. RADIION CLEANUP " OUR FINAL GOAL IS A SYSTEM OF SYSTEMS, WHERE MULTIPLE ROBOTS CAN ACCESS UNDERGROUND ENVIRONMENTS, MAP THEM, AND ANNOTATE THESE MAPS WITH RADIATION MEASUREMENTS." Kostas Alexis, head of the Autonomous Robots Lab, University of Nevada-Reno

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