UAV's for Quantitative Non-Destructive Inspection
Lead Research Organisation:
University of Strathclyde
Department Name: Electronic and Electrical Engineering
Abstract
This research studentship is focussed around the application of quantitative Non-Destructive Testing (NDT) techniques to power generation industrial asset inspection by way of Unmanned Aerial Vehicles (UAVs).
Within the current trend of operating lifespan extension for nuclear power generation facilities and the development of an increasingly renewable national energy portfolio, there is an appreciable need for enhanced inspection capability. For example in the case of wind turbines, the traditional inspection method, whereby an engineer would climb the turbine shaft and visually inspect the plant before applying other techniques as necessary, is seeing partial replacement by UAVs and their operators.
This research therefore intends to demonstrate the development and application of more rigorous NDT techniques to the inspection process following an in depth-review of the state of the art in related fields of study.
Aims & Objectives:
1. Optical inspired UAV positioning eliminating the need for physical manual control and ascension, thereby increasing the ability of the operator to inspect numerous geographically diffuse assets and reducing the associated personal safety concerns.
2. NDT Driven UAV platform modelling and control theory for optimised surface exploration speed or coverage in 3D space and relevant hardware development,
3. NDT Sensor design and implementation for optimised position invariant deployment
4. Image analysis techniques including Simultaneous Localisation and Mapping (SLAM) or defect classification, ultrasonic transducer appropriation for detection of structural faults including composite material delamination in turbine blades, or other similar works.
Thus, the ultimate goal of the studentship is to enhance engineering science within the field of airborne NDT through an iCASE PhD funding period of four years, supported by the EDF Energy renewables department and National Nuclear Laboratory.
Within the current trend of operating lifespan extension for nuclear power generation facilities and the development of an increasingly renewable national energy portfolio, there is an appreciable need for enhanced inspection capability. For example in the case of wind turbines, the traditional inspection method, whereby an engineer would climb the turbine shaft and visually inspect the plant before applying other techniques as necessary, is seeing partial replacement by UAVs and their operators.
This research therefore intends to demonstrate the development and application of more rigorous NDT techniques to the inspection process following an in depth-review of the state of the art in related fields of study.
Aims & Objectives:
1. Optical inspired UAV positioning eliminating the need for physical manual control and ascension, thereby increasing the ability of the operator to inspect numerous geographically diffuse assets and reducing the associated personal safety concerns.
2. NDT Driven UAV platform modelling and control theory for optimised surface exploration speed or coverage in 3D space and relevant hardware development,
3. NDT Sensor design and implementation for optimised position invariant deployment
4. Image analysis techniques including Simultaneous Localisation and Mapping (SLAM) or defect classification, ultrasonic transducer appropriation for detection of structural faults including composite material delamination in turbine blades, or other similar works.
Thus, the ultimate goal of the studentship is to enhance engineering science within the field of airborne NDT through an iCASE PhD funding period of four years, supported by the EDF Energy renewables department and National Nuclear Laboratory.
| Description | Ongoing works encompassed by this award have produced a number of findings relevant to both academic and industrial contexts. Through a collaborative effort involving researchers from the Automated Systems Laboratory of ETH Zurich, Switzerland, significant developments in terms of remote aerial inspection capability have been demonstrated. An integrated system has been produced, coupling the enhanced dynamic capability of a novel multirotor platform that grants advanced capability for multi-directional surface interaction with lightweight inspection hardware. Using an ultrasonic probe that eliminates the conventional requirement to carry a reservoir of couplant gel and can roll along inspection surfaces enables more efficient data capture flights with increased feature resolution along their path. This represents considerable progression towards the stated quantitative inspection goals of the PhD studentship and shows promise of a new inspection modality for structures with limited manned access, including on or off shore wind turbines and some nuclear facilities. Performance of this system has been quantified within a laboratory environment against samples representative of targeted defect modalities. Comparing captured ultrasonic measurements against the known sample conditions, the negative impact of motion of the aerial platform relative to the target surface and any non-ideal transducer alignment has been evaluated. Results show that inspection accuracy is in line with uncertainty boundaries of conventional methods, supporting the case for system practical utility. These findings open up subsequent research questions relating to how the process may be further improved to increase speed and enable additional inspection activity, targeting structures with non-planar or complex geometries. Such objectives would represent significant impact to the remote non-destructive testing field. In other work streams, assessment of photogrammetric inspection performance when conducted from a conventional multirotor platform has been carried out. Investigation focussed on the degradation of the 3D model reconstructed from multiple photographs of a feature-sparse wind turbine blade section in the presence of limited light levels, aerial platform motion and focal blurring as aerodynamic disturbances move the craft further from the structure. Numerical results inform boundaries as to the level of reconstruction accuracy that may be expected from aerial photogrammetry using current techniques. Strategies to mitigate these effects, including adaptive camera shutter speed and compensatory path planning using laser ranging data, are also proposed and have been evaluated for efficacy. This award has also seen the combination of the themes detailed above via physical modelling, design, control and quantitative performance assessment of a novel aerial robotics system. This unique vehicle combines the benefits of flexible aerial access offered by a multirotor with the stability of surface crawler wheeled robots to deliver remote, contact-based, in situ inspection of industrial assets such as pipework, storage tanks and pressure vessels. Initial empirical assessments have demonstrated successful deployment of immediate proximity visual inspection, allowing high resolution surface screening for sub-millimetre scale flaws and 3D reconstructions. In the future the vehicle will serve as an agent deploying other remote inspection sensor modes, directly supporting key themes in the research centre and wider academic community. Finally, increased research capability for the studentship within the Centre for Ultrasonic Engineering has also been generated through specialised training in the practical employment of metrology equipment including laser trackers, scanners and contact measurement machines. Similar training has been received across conventional non-destructive testing techniques including eddy current, x-ray and magnetic particle based methods. These provide a broad experience from which insight may be drawn during the remainder of the studentship and in pursuit of further research questions and targeted technology applications. |
| Exploitation Route | The practical benefits of remote inspection systems are well known with the context of in situ industrial inspection. They enable detailed health assessment of structures which require time consuming or expensive manned access. These techniques are commonly used to assess maintenance requirements so as to avoid unnecessary shutdown and quantify remaining lifespan of industrial plant assets such as petrochemical storage tanks or pipelines, the increasing profile of wind turbine and renewable energy structures within the UK or other civil engineering structures, including bridges and dams. The findings of this studentship act to quantify the accuracy of such inspection when conducted via intelligent or autonomous robotic agents, informing novel operations and maintenance strategies. While similar benefit may be found across a number of industries, ultimately, strategies embracing remote agents are expected to improve operational efficiency of energy generation assets, lowering running costs over the life of the asset and reducing the levelized cost of energy as the UK moves away from fossil-fuel based power generation. |
| Sectors | Aerospace, Defence and Marine,Construction,Electronics,Energy,Manufacturing, including Industrial Biotechology,Transport |
| Description | Findings from this research project have been employed in the creation of a spin-out company from ETH Zurich concerning the use of the multirotor platform developed for industrial inspection. This business employs ultrasonic measurement technology in a manner similar to that developed during the earlier collaborative experiments. Doing so they offer inspection of assets with challenging access including petrochemical tanks, composite aircraft components and structures from the renewable industry. Such services grant an economic benefit to those responsible for the operations and maintenance of the structures. The spin out company also sells the multirotor aircraft as a research platform to other institutes working along similar themes. |
| First Year Of Impact | 2020 |
| Sector | Aerospace, Defence and Marine,Construction,Electronics,Energy,Manufacturing, including Industrial Biotechology |
| Impact Types | Economic |
| Description | Collaboration with ETH Zurich Autonomous Systems Lab |
| Organisation | ETH Zurich |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | Researchers from the Centre for Ultrasonic Engineering (CUE) at the University of Strathclyde contributed expertise in lightweight robotically embedded ultrasonic inspection technologies towards the production of an integrated system for remote aerial inspection. Specifically, this entailed the sharing of access to custom developed ultrasonic transceiver hardware, interfacing software and pertinent operational knowhow. The PhD student, Robert Watson, travelled to the Swiss laboratory facility to integrate the hardware and conduct characterisation experiments with and has been responsible for the analysis of the resultant data. Further, Robert serves as first author on a draft manuscript of the results for journal publication. In support of ongoing activities, hardware similar to that used in initial experiments has been shared with the ETH researchers, with technical support for its usage still provided. |
| Collaborator Contribution | Researchers from the Autonomous Systems Lab of ETH Zurich provided access to their flight testing laboratory for the duration of the initial experiments, hosting Robert's visit for a period of two weeks in March 2019. As such they provided access to their novel Unmanned Aerial Vehicle platform and supported inspection hardware integration and testing activities. They continue to offer support in relation to aerial platform design and control theory during the manuscript drafting process. Discussions pertaining to the purchase of a research platform for use within CUE facilities are ongoing. |
| Impact | Collaboration brings together expertise from the robotics and ultrasonic inspection research disciplines. Output arising from this collaboration is as follows. Dry Coupled Ultrasonic Non-Destructive Evaluation Using an Over-Actuated Unmanned Aerial Vehicle - IEEE Transactions Journal. Deployment of Contact-Based Ultrasonic Thickness Measurements Using Over-Actuated UAVs - EWSHM BINDT NDT 2019 conference presentation. Aerial Interaction and Manipulation: Unsolved Challenges and Perspectives workshop poster. 2nd Scottish Ultrasound Annual scientific meeting poster and presentation. Pending European conference manuscript. |
| Start Year | 2019 |
| Description | Automation and Robotics Showcase |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Robert represented robotics / automation activities within the University of Strathclyde Centre for Ultrasonic Engineering (CUE) at the Automation and Robotics Showcase hosted by Highlands and Islands Enterprise in Inverness over the 6-7th of February 2019. This entailed providing technical overview of related activities conducted by CUE to attendees from varying disciplinary backgrounds while manning a trade-booth within the workshop concourse. Robert also operated the real-time robotic manipulator demonstration for caricature drawing of attendees, explaining how flexibility of path planning algorithms could be used in a multitude of industrial contexts. Additionally, logistical support was provided for shipping and set-up of robotic hardware used during the event. The event represented an excellent opportunity to network with other exhibitors in the Scottish robotics and automation discipline and was covered in televised news reports aired throughout the UK. |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://interface-online.org.uk/events/automation-and-robotics-showcase |
| Description | Images of Research 2019 |
| Form Of Engagement Activity | Engagement focused website, blog or social media channel |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Public/other audiences |
| Results and Impact | The images of research competition entails submission of a visually captivating image related to the researcher's project for public display in a collective exhibition within the University of Strathclyde and subsequent dissemination through its social media accounts. This annual competition and subsequent year-long exhibition brings the research conducted at Strathclyde to an audience of thousands of people visiting art galleries, museums and public spaces. The entry submitted by Robert Watson reached the final stages of the competition following selection by a panel of judges and was included in these physical and online public exhibitions. |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://www.imagesofresearch.strath.ac.uk/2019/gallery.php |
| Description | Industrial research presentations |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | This entailed multiple presentations of research outcomes to industrial representatives in related fields during their visits to the University of Strathclyde. Audience members include representatives from the National Nuclear Laboratory, EDF Energy, BAE Systems, Shell, Cavendish Nuclear, Babcock and the RCNDE working group. Increased awareness of project research goals and output amongst industrial leaders with view to securing further collaboration and funding opportunities. |
| Year(s) Of Engagement Activity | 2017,2018,2019 |
| Description | Lab Tour - Governing Body |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Policymakers/politicians |
| Results and Impact | Supported visit to the Centre for Ultrasonic Engineering (CUE) Facility for Innovation & Research in Structural Testing (FIRST) Laboratory on the 6th of September 2018 by the then Chancellor of the Exchequer, Philip Hammond, with output from research conducted by Robert presented by the Principal of the University, Jim McDonald. Also supported a visit to the FIRST lab by EPSRC Chief Exec Professor Lynn Gladden, with research outcomes presented by senior academics. Both activities acted to raise the profile of this project amid discussion of those with similar themes at a governmental level. |
| Year(s) Of Engagement Activity | 2018,2020 |
| Description | Lab Tour - School Outreach |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | Support was provided to multiple school visits to the Centre for Ultrasonic Engineering (CUE) Facility for Innovation & Research in Structural Testing Laboratory. This involved providing a tailored overview of all research activities conducted within the laboratory and supervising hands-on practical demonstrations of unmanned aerial inspection hardware. Pupils responded with multiple questions related to STEM degree options and increased enthusiasm / interest in related research conducted at the University of Strathclyde. |
| Year(s) Of Engagement Activity | 2017,2018,2019 |
| Description | Presentation at the inaugural Strathclyde - Waterloo Virtual Research Colloquium |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | An abstract for work in relation to project aerial inspection developments was submitted for inclusion as part of a virtual colloquium for doctoral researchers hosted between the University of Strathclyde and the University of Waterloo, Canada. This was accepted and Robert was nominated as 1 of 2 researchers from Strathclyde who went on to present their work within the event's Nuclear themed session. The event took place on the 12th of November and included an audience of international scholars across a range of fields, with a senior academic from Waterloo selected to lead an in depth Q&A session following the presentation. The presentation was well received and led to many insightful questions, furthering the profile of the project within the international community. |
| Year(s) Of Engagement Activity | 2020 |
| Description | University of Strathclyde Open Day |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Robert supported activities relating to the University of Strathclyde Open day for prospective Undergraduate students considering studies within the faculty of Electrical and Electronic Engineering (EEE) at the University of Strathclyde. This entailed providing guidance and discussion of experience within the university to numerous members of the public, primarily including potential students and their parents / guardians. The opportunity was also used to showcase ongoing PhD research with a demonstration of developed unmanned aerial vehicle hardware. This sparked multiple questions from the audience and increased awareness of the broader activities of the University of Strathclyde EEE department. |
| Year(s) Of Engagement Activity | 2018,2019 |
| URL | https://www.strath.ac.uk/studywithus/openday/ |