Robotic systems for retrieval of contaminated material from hazardous zones

Both Korean and UK nuclear industries share the same challenge of accessing large radio-chemical process environments to perform remote intervention tasks. In particular, both UK and Korea have identified a significant need for unmanned systems which can handle and retrieve contaminated materials in zones which are too hazardous to risk manned entries.

This project will directly address this need by developing novel robotic systems which can enter, monitor, and carry out manipulative actions on a wide variety of objects and materials in nuclear decommissioning environments, which would otherwise remain inaccessible and unmanageable.

The UoB-KAERI-NNL consortium will develop hardware, software, algorithms and control methods for a mobile robot manipulator, comprising an unmanned vehicle equipped with an arm and end-effectors (which could include hands and-or cutting devices), which can enter hazardous environments, perform a wide variety of manipulation tasks on materials inside those environments, and retrieve objects from the environment in a controlled fashion.

Additionally, we will develop a smaller "child" pipe-climbing robot, which can ride on the mother vehicle and be deployed onto pipe-work (prevalent in many nuclear installations) via the mother vehicle's manipulator arm. The purpose of the child robot is to inspect zones which would otherwise be inaccessible in highly complex and 3D nuclear plant environments, for example to reach places that are high, narrow or cluttered. Additionally, cameras mounted on the child robot can provide useful alternative views of the mother-vehicle, facilitating autonomous "visual-servoing" control of the manipulator arm, and/or better tele-operative control by an expert human operator.

The control approach will be one of "semi-autonomy", "tele-autonomy" or "variable-autonomy" which would therefore go beyond what has previously been attempted in nuclear environments. Traditionally, safety-critical industries have been very conservative about allowing the devolution of control from human operator to an autonomous machine, and have instead relied on direct tele-operation (e.g. a human controlling each joint of a robot arm by means of switches or joy-sticks). However, it is becoming increasingly clear that the combination of i) the vast scale of the decommissioning task, and ii) the complexity and high degrees-of-freedom of the robots needed to perform decommissioning, means that certain kinds of autonomous control will be required as "operator-assistance" technologies. For example, a human operator should be able to mouse-click on an object, and have the robot autonomously grasp it, rather than the human attempting to control two or more mobile base motors, six or more arm motors and two or more gripper fingers directly.

Additionally, autonomous sensing approaches, such as 3D reconstruction of environments by computational vision, will be necessary for both situational awareness of the remote human operator, and automatic planning and control algorithms running on the robot. We will develop advanced computer vision and path-planning algorithms, which will enable collision-free navigation of the robot vehicle, and successful autonomous arm and hand trajectories to effect robust grasps on arbitrarily shaped objects and materials.

Furthermore, we will develop advanced dynamics models and control methods to facilitate highly dynamic robot actions, such as braciation or swinging of the climbing child robot, or forceful actions of the mother mobile-maniplator with respect to contacts with its environment, for example cutting and grinding of objects, or dragging of grasped objects.

The overall aim is to enable the safe, unmanned retrieval of contaminated materials from hazardous zones.

Cleaning up the past half century of nuclear waste, in the UK alone (mostly at the Sellafield site), represents the largest environmental remediation project in the whole of Europe, and is projected to cost many tens of £billions. The worldwide decommissioning task is estimated to be in excess of $300billion. Much of this work can only be done by remote manipulation methods, because the high levels of radioactive material are hazardous to humans. Any country that possesses a nuclear plant, even without a current backlog of legacy waste, will face similar challenges when they begin decommissioning. The Republic of Korea currently has 23 nuclear reactors, and decommissioning is expected to start within 20 years.

This project will therefore deliver a number of key impacts:
1) It addresses the major UK societal challenge of cleaning up intolerable domestic legacy waste sites (impacting the UK population as a whole).

2) It enhances UK capabilities in decommissioning, where we have internationally recognised expertise, and which open up a >$300billion worldwide market to the UK economy (impacting the nuclear workforce in particular, and the overall UK economy more generally).

3) Robotics has been identified as "one of the 'eight great technologies' which will propel the UK to future growth" . This is thus a key emerging technology, where UK has internationally-leading research expertise. This project will cultivate and extend that expertise, as well as linking that expertise to a major practical industrial application (nuclear decommissioning) thereby creating an important pathway to impact for the nation's robotics achievements. I.e. impact on the UK robotics industry specifically, and the UK technology economy more generally.

5) It is a strong fit to the existing EPSRC portfolio, including:
i) The EPSRC DISTINCTIVE (Decommissioning, Immobilisation and Storage soluTIons for NuClear wasTe InVEntories) consortium, and;
ii) The EPSRC AIS (Autonomous and Intelligent Systems) program, in which the UK nuclear industry is a major stakeholder.
I.e. impact on the UK nuclear science and robotics research communities.

6) We have proposed specific pathways to impact, through our collaboration with the UK subsidiary of a major global industrial robotics company. Much of the new robotics technology developed during the project can find direct route to market through this collaboration. Thus, the proposed research will directly benefit local industry, as well as enhancing the industrial robotics capabilities available to customers worldwide.

7) We have proposed significant educational outreach and public communication activities to run in parallel with the research, thereby directly engaging with the non-expert population, promoting public awareness of the nuclear industry, and promoting study and career interest from young people in robotics specifically, and science and engineering more generally.