Andrew West

Positioning of underwater robots in enclosed or congested aquatic environments remains unsolved for field operations. Existing systems are generally suited for use in large open marine environments, not the enclosed and congested aquatic facilities common to industrial settings. In such environments, existing systems can suffer from strong echoes, multipath effects, poor coverage, and the reliance on new infrastructure and an assortment of features. Accurate and readily deployable positioning is a prerequisite for performing repeatable autonomous missions. The Collaborative Aquatic Positioning (CAP) system presented in this article uses a mixture of collaborative robotics and sensor fusion to solve this problem. The proposed positioning system is deployed in a large water tank, and repeatable autonomous missions are performed. Experimental results show that the system achieves real-time performance with mean Euclidean distance (MED) errors of 85.5–123.4 mm.

Cap and pin insulators are widely used in electricity transmission towers in power systems and are one of their key functional elements. This paper reports on a successful application of using electric field as an index to detect and locate shorted insulator units in a cap and pin string. Electro-optical (EO) probes were used to measure the electrical field, and a six-axis robotic arm, holding the probes, enabled electrical field mapping at different spatial locations. The electric field distribution was first plotted according to the measurements performed by EO probes travelling along straight lines parallel to the string, and then a closer examination between insulator sheds was conducted to evaluate the possibility of higher accuracy locating of shorted insulator units. The measured changes in electric field distribution were compared with predictions from corresponding electrostatic finite element analysis (FEA) models, confirming the ability of locating shorted units in the string based on observation of the field spatial distribution change. The electric field monitoring system was also further developed to achieve operator-free and automated data acquisition and recording. The reported methodology exhibits promising potential in live condition monitoring of insulator strings in high voltage (HV) towers.

Results obtained from characterizing the capabilities of a collimated cerium bromide (CeBr₃) detector developed for use on robotic platforms are reported. The detector’s field-of-view is collimated by a lead slit, and experiments have been performed with point radiation sources configured in a-priori known geometric scenarios. The collimated detector is scanned over radiation sources using gimbal control, acquiring a spectrum at each angle to obtain energy-resolved angular responses. These responses are then approximated by mathematical transforms to enhance localization accuracy. Various combinations of radionuclides have been used to demonstrate the effectiveness of this approach. The results reveal that expressing X-ray and [ ]-ray angular responses with an appropriate transform improves the resolving power of the slit collimator. This technique offers distinct advantages in robot deployments by enabling additional in-situ characterization capabilities without imposing additional limitations or requirements.

Positioning of underwater robots in congested and enclosed spaces remains unsolved for field operations. Well existing field ready systems are generally more suited to use in to use in large, open marine environments. In enclosed and congested environments, which are common in industrial settings, existing systems suffer from a mixture of issues, including: poor coverage, reliance on added infrastructure and the need for feature rich environments. Accurate and readily deployable positioning is a prerequisite for performing repeatable autonomous missions and therefore, until now, there has been a technological bottleneck in such environments. The Collaborative Aquatic Positioning system presented in this paper uses a mixture of collaborative robotics and sensor fusion to solve the problem. The proposed positioning system is deployed in a large water tank and repeatable autonomous missions are performed using the system’s position measurement for real-time feedback. Experimental results show that the system can achieve a Euclidean distance Root Mean Square Error (RMSE) of 70 mm while operating in real-time. The system enables almost complete coverage of the body of water in large pools without requiring fixed infrastructure, lengthy calibration, or feature rich environments. The Collaborative Aquatic Positioning system builds upon recent advances in mobile robot sensing and a recently developed leader follower control system to provide a step-change in positioning capability for real-world, high-precision autonomous underwater navigation.

Published version: Journal of Field Robotics https://doi.org/10.1002/rob.22329

The nuclear energy sector can benefit from mobile robots for remote inspection and handling, reducing human exposure to radiation. Advances in cyber–physical systems have improved robotic platforms in this sector through digital twin (DT) technology. DTs enhance situational awareness for robot operators, crucial for safety in the nuclear energy sector, and their value is anticipated to increase with the growing complexity of cyber–physical systems. The primary motivation of this work is to rapidly develop and evaluate a robot fleet interface that accounts for these benefits in the context of nuclear environments. Here, we introduce a multimodal immersive DT platform for cyber–physical robot fleets based on the ROS‐Unity 3D framework. The system design enables fleet monitoring and management by integrating building information models, mission parameters, robot sensor data, and multimodal user interaction through traditional and virtual reality interfaces. A modified heuristic evaluation approach, which accounts for the positive and negative aspects of the interface, was introduced to accelerate the iterative design process of our DT platform. Robot operators from leading nuclear research institutions (Sellafield Ltd. and the Japan Atomic Energy Agency) performed a simulated robot inspection mission while providing valuable insights into the design elements of the cyber–physical system. The three usability themes that emerged and inspired our design recommendations for future developers include increasing the interface's flexibility, considering each robot's individuality, and adapting the platform to expand sensor visualization capabilities.

Nuclear facilities have a regulatory requirement to measure radiation levels within Post Operational Clean Out (POCO) around nuclear facilities each year, resulting in a trend towards robotic deployments to gain an improved understanding during nuclear decommissioning phases. The UK Nuclear Decommissioning Authority supports the view that human‐in‐the‐loop (HITL) robotic deployments are a solution to improve procedures and reduce risks within radiation characterisation of nuclear sites. The authors present a novel implementation of a Cyber‐Physical System (CPS) deployed in an analogue nuclear environment, comprised of a multi‐robot (MR) team coordinated by a HITL operator through a digital twin interface. The development of the CPS created efficient partnerships across systems including robots, digital systems and human. This was presented as a multi‐staged mission within an inspection scenario for the heterogeneous Symbiotic Multi‐Robot Fleet (SMuRF). Symbiotic interactions were achieved across the SMuRF where robots utilised automated collaborative governance to work together, where a single robot would face challenges in full characterisation of radiation. Key contributions include the demonstration of symbiotic autonomy and query‐based learning of an autonomous mission supporting scalable autonomy and autonomy as a service. The coordination of the CPS was a success and displayed further challenges and improvements related to future MR fleets.