The Field Robotics Center (FRC)is working in the area of hazardous waste storage tank decontamination and decommissioning. Towards that end, the FRC has developed a capable mobile robot to gain access to, and move around inside a tank, deploying capable waste movement and handling tools such as a backhoe and plow, to help extricate the waste from the tank by moving waste to a central waste extrication system.
The idea of a mobile robot that can access tanks through existing `access pipes' without any facility modifications or much infrastructure support, is a very appealing concept achievable through innovative design concepts. The ability to gain access to any point on the tank floor in order to move all the waste to a retrieval device can be achieved through appropriate locomotion devices and customized tooling. Questions of fail-safe access and egress, locomotion capabilities, and waste hauling capacities will all be addressed in the development phase. The developed mobile robot, dubbed Houdini, is designed to allow entry through existing pipe risers to a tank by collapsing frame, locomotors, and tooling to fit into a circular pipe with a 20" (0.3m) inside diameter. After unfolding, the system will deploy the customized tooling which is currently envisioned to be a backhoe and a plow. Remote teleoperation and supervision of autonomous operation is performed at a remote control console incorporating control computers, joysticks, and several displays of on-board and bird's-eye view camera angles. Since the robot is tethered and hydraulically powered, a tether management system will remain atop the tank and lower the robot into the tank, feed additional tether as the robot moves around inside the tank, and retrieve the robot out of the tank. Tools which are currently envisioned as a baseline, consist of a collapsible backhoe and frontal plow (also termed a back-fill blade). On-board and bird's-eye-view cameras inserted through other risers will allow the operator located at a remote console to control and oversee the working performance of the robot at all times. The operational scenario would stress the utility of locomoting on and through all possible forms of media, pushing and haul- ing waste materials to a central waste extrication/processing location. Such an extrica- tion system inside the tank is needed to remove the waste to the outside of the tank where it can be safely packaged and stored for later processing. Vehicle maintenance, tooling exchange and decontamination can be performed inside the exterior deployment and attached maintenance pod, without exposing humans or the environment to any hazardous waste materials.
A spec-sheet and photographs of a kinematic prototype have been drafted and are shown below
