Coded Excitation of Ultrasound for Improved Signal Acquisition in Pipeline Inspection Robots

This project is investigating the use of advanced excitation techniques to improve the performance of inline inspection robots. Inline robots are used to monitor the structural health and integrity of large pipeline structures. This project aims to understand how advanced excitation techniques may help to improve the sensitivity, energy consumption, size, and design of ultrasound acquisition systems on inline robots.

Currently, traditional excitation methods with high voltage pulses are used to yield sufficient Signal-to-Noise Ratios (SNRs) in the acquired signals. However, high voltage pulsers are inefficient [2] which increases the required energy that must be stored and carried by the robot. Additionally, typical robots incorporate large numbers of ultrasound transducers to ensure the full pipe structure is inspected which introduces problems with crosstalk. Crosstalk from both electronic and ultrasonic pickup between adjacent measurements complicates signal analysis and imposes spacing constraints between transducers. Signal variation introduced by differences across transducers also complicates the signal analysis. These challenges result in strict design requirements and an increased robot build and operating cost.

Coded Excitation has the potential to overcome these challenges. Literature has shown that Coded Excitation allows measurements with low excitation voltages [3]; can be used to optimise and standardise waveforms from transducers [4]; and can reduce crosstalk and increase imaging rate [5]. Therefore, Coded Excitation has the potential to improve inline robot performance and design.

This project initially focussed on the fundamentals of Coded Excitation. This involved exploring how Coded Excitation impacts SNR and how the code can be optimised for different measurements. The project now looks to investigate: the robustness of Coded Excitation on different hardware; alternative sequence types and their performance limits; sequence orthogonality and crosstalk; optimising transducer standardisation; and hardware requirements for low-power modular implementations.

The proposed CDT in NDE will deliver impact (Industrial, Individual and Societal) by progressing research, delivering commercial benefit and training highly employable doctoral-level recruits able to work across industry sectors.

Industry will benefit from this CDT resulting in competitive advantage to the industrial partners where our graduates will be placed and ultimately employed. The global NDE market itself has a value of USD15 billion p.a. [Markets and Markets NDE report January 2017] and is growing at 8% per year. Our partners include 49 companies, such as Airbus, Rolls-Royce, EDF, BAE Systems, SKF and Shell, whose ability to compete relies on NDE research. They will benefit through a doctoral-level workforce that can drive forward industrial challenges such as increased efficiency, safer operation, fewer interruptions to production, reduced wastage, and the ability to support new engineering developments. Our 35 supply chain partners who, for example, manufacture instrumentation or provide testing services and are keen to support the proposed CDT will benefit through graduates with skills that enable them to develop innovative new sensing and imaging techniques and instrumentation. To achieve this impact, all CDT research projects will be co-created with industry with an impact plan built-in to the project. Our EngD students will spend a significant amount of their time working in industry and our PhDs will be encouraged to take up shorter secondments. This exposure of our students to industry will lead to more rapid understanding, for both parties, of the barriers involved in making impact so that plans can be formulated to overcome these.

Individual impact will be significant for the cohorts of students. They will be trained in an extremely relevant knowledge-based field which has a significant demand for new highly skilled doctoral employees. These graduates will rejuvenate an ageing workforce as well as filling the doctoral skills and capability gaps identified by industry during the creation of this CDT. Our industrial partners will be involved in training delivery, e.g. entrepreneurial training to equip our graduates with the skills needed to translate new research into marketed products. Many of the partners are existing collaborators, who have been engaged regularly through the UK Research Centre in NDE (RCNDE), an industry-university collaboration. This has enabled the development of a 5,10 & 20 year vision for research needs across a range of market sectors and the CDT training will focus on these new priorities. Over the duration of the CDT we will actively discuss these priorities with our industry partners to ensure that they are still relevant. This impact will be achieved by a combination co-creation and collaboration on research projects, substantive industrial placements and as well as communication and engagement activities between academic partners and industry. Events aimed at fostering collaboration include an Annual CDT conference, technology transfer workshops, networking events as well as university visits by industrialists and vice versa, forming a close bond between research training and industrial impact. This approach will create lasting impact and ensure that the benefits to students, industry and society are maximised.

Society will benefit from this CDT through the research performed by our CDT graduates that will underpin safety and reliability across a wide range of industries, e.g. aerospace, energy, nuclear, automotive, defence and renewables. As NDE is an underpinning technology it feeds into many of the UK Government's Industrial Strategy Challenge Fund Grand Challenges, for example in energy, robotics, manufacturing and space. It is aligned to the EPSRC prosperity outcomes, e.g. the Productive Nation outcome requires NDE during manufacture to ensure quality and the Resilient Nation requires NDE to ensure reliable infrastructure and energy supplies.