Controlling Multistability in Vibro-Impact Systems: Theory and Experiment

Lead Research Organisation: University of Exeter
Department Name: Engineering Computer Science and Maths

Abstract

UK has been one of the industrial powerhouses of Europe from the time of the Industrial Revolution onwards. Today, it is a major challenge for power intensive industries in the UK to optimize their energy strategy in order to ensure long-term sustainable economic growth. Strategies for engineering systems to improve their energy efficiency are to become vital. This project intends to unravel a practical question: can we improve the energy efficiency of engineering systems through judiciously switching between their coexisting states? The proposed research aims to develop a novel control strategy for multistable engineering systems in order to maintain their performance within a satisfactory level by implementing an energy-optimal steering. This will be achieved by studying a novel non-smooth dynamical system, namely the vibro-impact capsule system through both theoretical development and experimental validation. For the first time, the project aims to use the system's basins of attraction (BoA) for control purpose, and seeks the minimum energy solution by exploiting the positive attributes of multistability. In the long term, this project will be fundamental for the realization of energy efficient control, which will provide safe, reliable, and efficient operations for future engineering systems. The approach to realize this ambitious goal in a 21 month project is: (i) to study multistability in the vibro-impact capsule system and its BoA numerically and experimentally; (ii) to develop a new control strategy for switching between different coexisting attractors; and (iii) to verify the proposed control strategy experimentally using the experimental rig of the capsule system.

Planned Impact

The proposed practicable control strategy for controlling multistability will be fundamental for the realization of energy efficient control, which will provide safe, reliable, and efficient operations for future engineering systems impacting on almost every industrial sector, from energy saving systems (e.g. energy harvesting) and rotary machinery (e.g. jet engine) to small consumer devices (e.g. hard disk). Therefore, this research project will have a significant impact on the economy, as well as society, as both industrial companies and individual consumers will be the ultimate beneficiaries of such advanced technology.

Vibro-impact engineering systems, such as milling machines, rotary engines, and moling rigs, require large amounts of power produced through the use of fossil fuels (i.e. coal, oil, and natural gas), and any undesired vibrations and impacts may cause these machineries to become inefficient. According to the Energy Consumption in the UK (2016), in 2015, the energy consumption of road transport increased by 1.4% from 2014, to 40,521 ktoe, and the energy consumption of air transport increased by 1.2%, to 12,573 ktoe. At the global scale, the utilization of fossil fuels is still dominant supplying about 85.9% of the world's energy in 2015, and the demand for fossil fuels is increasing. The consequences of the combustion of fossil fuels for power production are serious threats to the environment, causing global warming and climate change. According to the BP Statistical Review (2016), global CO2 emissions from energy consumption grew by 0.1% in 2015. Thus, for power intensive industries in the UK, this scenario strongly motivates the need for energy efficiency. In the long term, this proposal serves exactly this aim, by developing energy saving control technology for a broad range of industrial applications. For example, the energy sector has a significant effect on the UK in terms of its impact on the economy. It aims to maximise the economic production of the UK's offshore oil and gas resources in future decades by enabling industry to better understand complex reservoirs, reducing exploration costs, and improving offshore efficiency. The control strategy developed in this project will contribute directly, revolutionizing current drilling technologies, and ultimately enabling more efficient drilling through saving operational time and reducing drilling costs.

One of the outputs of this project, the development of a novel experimental test bed, will be of fundamental importance to the development of future inspection devices. Experimental investigation of the novel capsule system in this project will provide theoretical basis and proof-of-conception demonstration for developing the capsule prototype for medical diagnosis and engineering pipeline inspection. The direct impact will be on the robotics research groups working on minimally invasive surgery, smart sensor network, and engineering pipeline inspection. Consequently, success in this project will open doors for new collaborations in wider research fields.

Thus, the pathways to impact can be summarized as:
- Publications in high quality journals of international readership, and presentation of results in prestigious international conferences;
- Presenting results in industrial conference, and directly interacting with industrial researchers to maximize their awareness of such advanced technology;
- Organization of an international symposium to bring together specialists in the relevant fields so that the research outcome generates direct impact on these beneficiaries;
- Training a postdoctoral research associate and two PhD students in the emerging field of nonlinear dynamics and control;
- Maximizing public awareness of the societal benefits of the research via project website and social media.

Publications

10 25 50
 
Description There are several new knowledge generated in this project.
1) A new feature, namely multistability, has been utilised to improve the performance of many engineering systems;
2) A systematic numerical continuation method implemented via the continuation platform COCO has been proposed for investigating engineering vibrating systems;
3) A position feedback control strategy for controlling engineering systems with multistability has been proposed.

New research collaborations were developed, including:
1) The Royal Devon and Exeter NHS Foundation Trust;
2) Shangxian Minimal Invasive Inc, a healthcare product company;
3) University of Dundee;
4) Peking University;
5) Tsinghua University;
6) The Chinese University of Hong Kong;
7) MIT;
8) ETH Zurich
Exploitation Route The PI will disseminate his research findings to potential stakeholders, e.g. oil and gas, healthcare technology, or robotic companies, through email communications, conference presentations, and industrial meetings. He will also actively circulate these findings to the academic researchers who can benefit from this research.
Sectors Agriculture, Food and Drink,Energy,Healthcare

 
Description At the school open day, Dr Liu presented the experimental rig developed in this project to visiting students and their parents. Dr Liu briefly introduced the project and the concept of multistability and how it can be used in engineering.
First Year Of Impact 2021
Sector Education
Impact Types Policy & public services

 
Description Capital award for core equipment
Amount £269,363 (GBP)
Funding ID EP/T023635/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 01/2020 
End 07/2021
 
Description Utilising the Vibro-Impact Self-Propulsion Technique for Gastrointestinal Endoscopy
Amount £31,674 (GBP)
Funding ID EP/R043698/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 07/2018 
End 02/2019
 
Description When a Micro-Robot Encounters a Bowel Lesion
Amount £202,450 (GBP)
Funding ID EP/V047868/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 01/2021 
End 01/2023
 
Title A numerical approach for the bifurcation analysis of nonsmooth delay equations 
Description Due to the complex analytical framework and numerical challenges related to delayed nonsmooth systems, there exists so far no dedicated software package to carry out numerical continuation for such type of systems. This work proposes the first ever method for nonsmooth dynamical systems with delay that allows a numerical bifurcation analysis by using existing software packages. This method will be of great interest to both mathematicians and engineers who are working on dynamical systems and engineering nonlinearity. This work initiates a new research area which has not been investigated before. 
Type Of Material Technology assay or reagent 
Year Produced 2019 
Provided To Others? Yes  
Impact N/A 
URL https://www.sciencedirect.com/science/article/pii/S1007570419304149
 
Description Escuela Superior Politécnica del Litoral 
Organisation Escuela Superior Politécnica del Litoral
Country Ecuador 
Sector Academic/University 
PI Contribution Dr Liu has provided his expertise in control and experimental data.
Collaborator Contribution Prof. Prof. Joseph Páez Chávez has provided his expertise in numerical analysis.
Impact 1. http://dx.doi.org/10.1098/rspa.2017.0500 2. https://doi.org/10.1007/s11071-017-3855-9 3. https://doi.org/10.1177/0954406218766200 4. http://dx.doi.org/10.1007/s11012-017-0801-3
Start Year 2017
 
Description Plexus Ocean Systems Ltd 
Organisation Plexus
Country United Kingdom 
Sector Private 
PI Contribution My team has carried out numerical analysis for gaining fundamental insights into the stability issues of the company's products, and provide a new approach to improve their stability.
Collaborator Contribution The company has provided engineer staff time and access to their experimental data.
Impact A technical report
Start Year 2017
 
Description Escuela Superior Politécnica del Litoral 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Professor Joseph Páez Chávez from Department of Mathematics at the Escuela Superior Politécnica del Litoral (Guayaquil, Ecuador) was invited to give a seminar entitled "A model for Dengue transmission dynamics with seasonal effects and impulsive control" at the University of Exeter. Postgraduate students, researchers and academic staffs from Mathematics and Engineering disciplines attended the seminar and discussed the research question.
Year(s) Of Engagement Activity 2018
 
Description Liverpool John Moores University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact The PI has given a research seminar at the Faculty of Engineering and Technology, Liverpool John Moores University. Research questions have been discussed and potential collaboration has been proposed.
Year(s) Of Engagement Activity 2018
 
Description Peking University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The PI has given a talk in the College of Engineering at Peking University to present the recent findings by his research team. Attendees have shown great interests of the PI's project and extensive discussions have been made after the talk.
Year(s) Of Engagement Activity 2018
 
Description RDEFT Engagement 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact The PI has organised a meeting with the consultant gastroenterologist for Endoscopy at the Royal Devon and Exeter NHS Foundation Trust (RDEFT) to introduce his self-propulsion control technique which might be used for improving gastrointestinal endoscopy. Relevant research questions and potential collaboration opportunity have been discussed. This engagement has led to the PI's EPSRC Healthcare Technologies Discipline Hopping project with the RDEFT.
Year(s) Of Engagement Activity 2018
 
Description SMI Engagement 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact The PI has visited Shangxian Minimal Invasive Inc (SMI), a healthcare product company based in China, and gave a presentation about his research works. The possibility of using the PI's self-propulsion control technique for capsule endoscopy has been discussed, and potential collaboration has been proposed.
Year(s) Of Engagement Activity 2018
 
Description Tsinghua University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The PI has given a research seminar at Department of Mechanical Engineering, Tsinghua University. Recent advances of PI's research project have been reported followed by extensive discussions with researchers and postgraduate students at Tsinghua. Potential collaboration opportunity has been proposed.
Year(s) Of Engagement Activity 2018
 
Description University of Dundee 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Dr Luigi Manfredi, an researcher of School of Medicine at the University of Dundee, was invited to give a talk entitled "Design and Construction of a Mini Snake-Like Medical Robot" at Exeter. Postgraduate students, researchers and academic staffs have attended the seminar. Potential collaboration on robotic endoscopy has been discussed.
Year(s) Of Engagement Activity 2017
 
Description University of Electronic Science and Technology of China 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A group of academic staffs (7 people) from School of Aeronautics and Astronautics at the University of Electronic Science and Technology of China visited the University of Exeter and the PI's research lab. Research project has been shown and experiments were presented. Three research seminars were also given by the visitors to explore potential collaboration opportunity.
Year(s) Of Engagement Activity 2018