Robotics for nuclear power plants - Challenges and future perspectives

Use of robotics and computerized tools in Nuclear Power Plants (NPPs) has been identified as a highly recommended practice by IAEA. The key rationale of robotics application has always been to avoid human exposure to hazardous environments and tasks ranging from scrutiny and general maintenance to decontamination and post accidental activities. To execute these activities, robots need to incorporate artificial intelligence, improved sensors capability, enhanced data fusion and compliant human like leg and hand structures for efficient motions. Next generation robotic systems in NPPs are expected to work in full autonomous mode in contrast to the current semi-autonomous scenarios. Far future systems could deploy humanoid robots as well. This paper presents state-of-theart of robotics developed for NPPs, associated challenges and finally comments on future directions

Systematic Approach for the Development of Remote Handling System Concepts for High Energy Physics Research Facilities

Equipment maintenance is one of the most important areas in the life-cycle management of High Energy Physics (HEP) facilities. In HEP facilities (such as CERN, ISOLDE, GSI/FAIR,GANIL, FRIB and ESS), beam intensities are increasing. Ionizing radiation is a significant hazard. The ionizing radiation directly affects the health of radiation workers and therefore it is desirable to reduce human intervention through robotic operations. The Facility of Antiproton and Ion Research (FAIR), a HEP facility under construction in Darmstadt, Germany, will house the world’s most powerful Super Fragment Separator(Super-FRS) facility, which will require remote maintenance. One section of the Super-FRS is termed the main tunnel. This is 160m long and has four focal planes. The Super-FRS beamline inserts will require remote maintenance and remote inspection. To carry out these Remote Handling (RH) tasks, a RH system for the Super-FRS main tunnel is essential.RH equipment for HEP facilities are complex systems. They must operate within an intricate environment with multiple interfaces. However, there is very limited literature on how to approach the development and evaluation of RH concepts at HEP facilities even though various facilities have developed RH systems tailored to their individual environments.This thesis proposes new systematic approach for developing and evaluation of RH concept designs targeted to help maintenance procedures at HEP facilities. The systematic approach is composed of Systems Engineering (SE) State of the Art practices molded to fit HEP facilities needs and requirements. The SE approach for HEP facilities focuses on finding optimum RH solution by exploiting HEP facilities limited resources available compared to nuclear power production industry. The systematic approach is tested to develop the RH maintenance solution for Super-FRS main tunnel scenario for FAIR facility. The practice carried out during this research work resulted in the best possible RH solution for Super-FRS and is currently under development for the Super-FRS facility.The research work to develop systematic approach for development of RH system was based on a very critical State of the Art study that has not been carried for HEP facilities till now. The State of the Art studies explores the HEP facilities in detail and results in: classification of HEP facilities RH environments, classification of RH equipment currently used at HEP facilities and present status of SE knowledge integration within HEP facilities. The systematic approach to develop RH system and knowledge attained during State of the Art studies are utilized to develop three RH system concept designs that fulfill the Super-FRS RH requirements. This research work focuses on collaborating between RH experts to conduct reliable and creditable trade-off analysis for RH system concepts evaluation. The aim of collaboration with RH experts is to develop diversify the systematic approach for RH system concept development. The collaboration and the State of the Art studies enable the model to formalize the procedures that will ensure the integration of RH needs into facility’s development by classifying (Commercial Off-the–Shelf (COTS)) RH equipment and by identifying key steps in the development of RH concepts.The developed RH concepts for Super-FRS are evaluated for requirements traceability, functional analysis, radiation dose analysis, possible system failure scenarios, including cost estimates, and task sequence optimization analysis. The result of trade-off analysis is delivered in the form of optimal RH system design that fulfills the RH requirements and will be developed to carry out RH tasks at Super-FRS facility.This thesis provides details concerning each concept design’s merits and demerits, along with suggestions for design changes needed to improve RH system’s flexibility and performance. The systematic approach used to develop the RH concepts was used to identify and address the critical issues with Super-FRS tunnel layout, beamline insert designs, storage / transport of activated parts, and remote maintenance integration at very early stage of HEP facility design.The research work in this thesis paves the way for the future systematic RH systems concepts design, and development practices; by moving beyond the classical approaches to develop concept designs at the HEP facilities. The conclusion will also present a summary design comparison, relevant technologies, advantages, limitations and future research work opportunities.<br/

Development of an Intelligent Robotic Manipulator

The presence of hazards to human health in chemical process plant and nuclear waste stores leads to the use of robots and more specifically manipulators in unmanned spaces. Rapid and accurate performance of robotic arm movement and positioning, coupled with a reliable manipulator gripping mechanism for variable orientation and a range of deformable and/or geometric and coloured products, will lead to smarter/intelligent operation of high precision equipment. The aim of the research is to design a more effective robot arm manipulator for use in a glovebox environment utilising control kinematics together with image processing / object recognition algorithms and in particular the work is aimed at improving the movement of the robot arm in the case of unresolved kinematics, seeking improved speed and performance of object recognition along with improved sensitivity of the manipulator gripper mechanism A virtual robot arm and associated workspace was designed within the LabView 2009 environment and prototype gripper arms were designed and analysed within the Solidworks 2009 environment. Visual information was acquired by barrel cameras. Field research determines the location of identically shaped objects, and the object recognition algorithms establish the difference between them. A touch/feel device installed within the gripper arm housing ensures that the applied force is adequate to securely grasp the object without damage, but also to adapt to any slippage whilst the manipulator moves within the robot workspace. The research demonstrates that complex operations can be achieved without the expense of specialised parts/components; and that implementation of control algorithms can compensate for any ambiguous signals or fault conditions that occur through the operation of the manipulator. The results show that system performance is determined by the trade-off between speed and accuracy. The designed system can be further utilised for control of multi-functional robots connected within a production line. The Graphic User Interface illustrated within the thesis can be customised by the supervisor to suit operational needs

Evaluating the Radiation Tolerance of a Robotic Finger

In 2024, The Large Hadron Collider (LHC) at CERN will be upgraded to increase its luminosity by a factor of 10 (HL-LHC). The ATLAS inner detector (ITk) will be upgraded at the same time. It has suffered the most radiation damage, as it is the section closest to the beamline, and the particle collisions. Due to the risk of excessive radiation doses, human intervention to decommission the inner detector will be restricted. Robotic systems are being developed to carry out the decommissioning and limit radiation exposure to personnel. In this paper, we present a study of the radiation tolerance of a robotic finger assessed in the Birmingham Cyclotron facility. The finger was part of the Shadow Grasper from Shadow Robot Company, which uses a set of Maxon DC motors

From plain visualisation to vibration sensing: using a camera to control the flexibilities in the ITER remote handling equipment

Thermonuclear fusion is expected to play a key role in the energy market during the second half of this century, reaching 20% of the electricity generation by 2100. For many years, fusion scientists and engineers have been developing the various technologies required to build nuclear power stations allowing a sustained fusion reaction. To the maximum possible extent, maintenance operations in fusion reactors are performed manually by qualified workers in full accordance with the "as low as reasonably achievable" (ALARA) principle. However, the option of hands-on maintenance becomes impractical, difficult or simply impossible in many circumstances, such as high biological dose rates. In this case, maintenance tasks will be performed with remote handling (RH) techniques. The International Thermonuclear Experimental Reactor ITER, to be commissioned in southern France around 2025, will be the first fusion experiment producing more power from fusion than energy necessary to heat the plasma. Its main objective is “to demonstrate the scientific and technological feasibility of fusion power for peaceful purposes”. However ITER represents an unequalled challenge in terms of RH system design, since it will be much more demanding and complex than any other remote maintenance system previously designed. The introduction of man-in-the-loop capabilities in the robotic systems designed for ITER maintenance would provide useful assistance during inspection, i.e. by providing the operator the ability and flexibility to locate and examine unplanned targets, or during handling operations, i.e. by making peg-in-hole tasks easier. Unfortunately, most transmission technologies able to withstand the very specific and extreme environmental conditions existing inside a fusion reactor are based on gears, screws, cables and chains, which make the whole system very flexible and subject to vibrations. This effect is further increased as structural parts of the maintenance equipment are generally lightweight and slender structures due to the size and the arduous accessibility to the reactor. Several methodologies aiming at avoiding or limiting the effects of vibrations on RH system performance have been investigated over the past decade. These methods often rely on the use of vibration sensors such as accelerometers. However, reviewing market shows that there is no commercial off-the-shelf (COTS) accelerometer that meets the very specific requirements for vibration sensing in the ITER in-vessel RH equipment (resilience to high total integrated dose, high sensitivity). The customisation and qualification of existing products or investigation of new concepts might be considered. However, these options would inevitably involve high development costs. While an extensive amount of work has been published on the modelling and control of flexible manipulators in the 1980s and 1990s, the possibility to use vision devices to stabilise an oscillating robotic arm has only been considered very recently and this promising solution has not been discussed at length. In parallel, recent developments on machine vision systems in nuclear environment have been very encouraging. Although they do not deal directly with vibration sensing, they open up new prospects in the use of radiation tolerant cameras. This thesis aims to demonstrate that vibration control of remote maintenance equipment operating in harsh environments such as ITER can be achieved without considering any extra sensor besides the embarked rad-hardened cameras that will inevitably be used to provide real-time visual feedback to the operators. In other words it is proposed to consider the radiation-tolerant vision devices as full sensors providing quantitative data that can be processed by the control scheme and not only as plain video feedback providing qualitative information. The work conducted within the present thesis has confirmed that methods based on the tracking of visual features from an unknown environment are effective candidates for the real-time control of vibrations. Oscillations induced at the end effector are estimated by exploiting a simple physical model of the manipulator. Using a camera mounted in an eye-in-hand configuration, this model is adjusted using direct measurement of the tip oscillations with respect to the static environment. The primary contribution of this thesis consists of implementing a markerless tracker to determine the velocity of a tip-mounted camera in an untrimmed environment in order to stabilise an oscillating long-reach robotic arm. In particular, this method implies modifying an existing online interaction matrix estimator to make it self-adjustable and deriving a multimode dynamic model of a flexible rotating beam. An innovative vision-based method using sinusoidal regression to sense low-frequency oscillations is also proposed and tested. Finally, the problem of online estimation of the image capture delay for visual servoing applications with high dynamics is addressed and an original approach based on the concept of cross-correlation is presented and experimentally validated

A shuttle and space station manipulator system for assembly, docking, maintenance, cargo handling and spacecraft retrieval (preliminary design). Volume 3: Concept analysis. Part 1: Technical

Information backing up the key features of the manipulator system concept and detailed technical information on the subsystems are presented. Space station assembly and shuttle cargo handling tasks are emphasized in the concept analysis because they involve shuttle berthing, transferring the manipulator boom between shuttle and station, station assembly, and cargo handling. Emphasis is also placed on maximizing commonality in the system areas of manipulator booms, general purpose end effectors, control and display, data processing, telemetry, dedicated computers, and control station design