Prof Yang Liu
Associate Professor in Dynamics and Control
(Streatham) 4654
01392 724654
Overview
Education:
- BEng in Automation, Hunan University, China, 1999 - 2003
- MSc in Control Systems, University of Sheffield, UK, 2004 - 2005
- PhD in Control Engineering, Staffordshire University, UK, 2006 - 2010
Employment History:
- Research Fellow, University of Aberdeen, Aberdeen, UK, 2010 - 2013
- Lecturer in Mechanical Engineering, Robert Gordon University, Aberdeen, UK, 2013 - 2016
- Lecturer in Engineering, University of Exeter, Exeter, UK, 2016 - 2019
- Senior Lecturer in Engineering, University of Exeter, Exeter, UK, 2019 - 2022
- Associate Professor in Dynamics and Control, University of Exeter, Exeter, UK, 2022 - now
- Honorary Lecturer, Royal Devon University Healthcare NHS Foundation Trust, UK, 2018 - now
Research Interests:
- Controlled gastrointestinal endoscopies (Project 1) (Project 2)
- Early detection of bowel cancer (Project 1) (Project 2)
- Microrobots for metastatic cancer detection and therapy (Project 1) (Project 2)
- Control of non-smooth dynamical systems (Project 1) (Project 2)
Awards & Achievements:
- Stanford & Elsevier's Global Top 2% Scientists list since 2019
- Ali H. Hayfeh Prize, Int. Nonlinear Dynamics Conference 2021
- 1st place, poster competition at the 4th Annual IEEE UK and Ireland RAS Chapter Conf.
- Lab Science Bursary Award, British Society of Gastroenterology Annual Meeting 2019
- IMechE Group Project Award
- Young Delegates Award, the 14th IFToMM World Congress
- Best Student Paper Award, the 15th Int. Conf. Automation & Computing
Media Coverage:
- "Micro robots in the gut could detect early signs of colon cancer" by CORDIS
- "A pill sized robot that can drive inside large intestines" interviewed by Robohub
- "New Horizons for research through adventurous projects" by UKRI
- "Pioneering a new self-propulsion technique for small bowel endoscopy" by Exeter Research and Innovation Blog
Research Activities:
- Executive board member, International Society of Mechanical System Dynamics, from 2023 to 2026
- Program committee member, the Int. Conf. on Manipulation, Automation and Robotics at Small Scales (MARSS), since 2024
- Editorial board member, Subject Editor in Nonlinear Dynamics, since 2023
- Scientific committee member, the 2nd Int. Conf. on Mechanical System Dynamics, China
- Symposium chair, Biomechanics and Small-Scale Robots, the 3rd Int. Nonlinear Dynamics Conference 2023, Italy
- Symposium chair, 2022 Exeter International Symposium on Small-Scale Robots, Exeter (online), UK
- Associate editor, the 9th IEEE RAS/EMBS International Conference on Biomedical Robotics & Biomechatronics 2022, Korea
- Lead guest editor, SI: Self-propelled robots: from theory to applications at Meccanica
- Symposium chair, Biocapsule Robots, the 2nd Int. Nonlinear Dynamics Conference 2021, Italy
- Symposium chair, Biomechanics and Capsule Robots, the 1st Int. Nonlinear Dynamics Conference 2019, Italy
- Symposium chair, Modelling of Friction and Dynamics of Frictional Oscillators, Int. Conf. Engineering Vibration 2017, Bulgaria
Live and Forthcoming Projects:
- Development of the initial prototype of a pill sensor to detect colonic polyps and early bowel cancer, MRC (MR/Y503411/1), PI, £247,147, 02/2024-07/2025
- Late proof-of-concept demonstration of a clinician-controlled capsule device for lower gastrointestinal endoscopy, EPSRC IAA, PI, £53,180, 11/2023-03/2024
- Preclinical assessment of a vibrational device for early bowel cancer diagnosis, MRC IAA, PI, £44,857, 07/2023-04/2024
- WORMS: When micro-robots encounter metastatic cancer in the adjacent capillaries, Marie Skłodowska-Curie Actions Postdoctoral Fellowship (EP/Y016017/1), PI, €236,748, Secondment supervisor: Prof. Antoine Ferreira (INSA Centre Val de Loire), 10/2023-09/2025
- AGENT: Targeting high efficient energy harvesting via controlling multistability, Marie Skłodowska-Curie Actions Postdoctoral Fellowship (EP/Y016130/1), PI, €236,748, Secondment supervisor: Prof. Przemysław Perlikowski (Lodz University of Technology), 10/2023-09/2025
- On the piecewise-smooth dynamics of robot-cancer interaction at microscale, EPSRC Mathematical Sciences DTP (2581433), PI, £88,503, 10/2021-09/2025
- On the dynamics of two contacting bodies under frictional sliding, Royal Society, PI, £11,685, 03/2021-03/2024 (ranked in Top 7th of 56 funded projects, see News)
Finished Projects:
- OMEGA: On the modelling of micro-robots in the gut: a non-smooth dynamics approach, Marie Skłodowska-Curie Actions Individual Fellowship (101018793), PI, €212,933, Secondment supervisor: Prof. Bradley J. Nelson (ETH Zurich), 10/2021-09/2023 (marked 97 out of 100, ranked in Top 2.95% in Engineering Panel, and about 1,630 funded projects out of 11,300 applications)
- When a micro-robot encounters a bowel lesion, EPSRC New Horizons (EP/V047868/1), PI, £202,450, 05/2021-06/2023 (about 100 funded projects out of over 1,200 applications, see EPSRC News)
- Developing AI enabled low-cost microcontrollers, EPSRC SMM CDT, PI, £80,000, 11/2019-10/2023
- Development of a mathematical tool for piecewise-smooth delay differential equations: a micro-robot’s perspective, EPSRC (EP/W52265X/1), PI, £TBC, 10/2021-02/2022
- EPSRC Capital award for core equipment (EP/T023635/1), Co-I, £269,363, 11/2019-07/2021
- Controlling multistability in vibro-impact systems: theory and experiment, EPSRC (EP/P023983/1), PI, £101,147, 10/2017-06/2019
- Utilising the vibro-impact self-propulsion technique for gastrointestinal endoscopy, EPSRC (EP/R043698/1), PI, £31,674, 08/2018-02/2019
- Control of multistable dynamical systems with applications in oil and gas industry, the Carnegie PhD scholarship, PI, £54,159, 10/2015-03/2019
- Mathematical modelling and optimisation of a downhole anti stick-slip tool for reduction of torsional vibrations, ETP PhD Studentship collaborated with Tomax Ltd., Co-PI, £82,423, 10/2014-03/2018
- Agri-Tech in China: Newton Network+, Pathfinder Awards (PF002), PI, £4,914, 07/2017
- Design, modelling and implementation of a capsule system for pipeline pigging inspection, IMechE Group Project Award, £2,500, 10/2015-03/2016 (News 1, News 2)
- Development of an experimental test rig for a vibro-impact capsule system, the Carnegie Trust Small Research Grant (No 31841), PI, £2,140, 08/2014-07/2015
Prof. Liu's lab facilities can be found here, and his lab's Youtube channel can be viewed from here.
Publications
Copyright Notice: Any articles made available for download are for personal use only. Any other use requires prior permission of the author and the copyright holder.
| 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | Patents |
2024
- Tian B, Liu Y, Monsalve JL. (2024) Nonlinear Characteristics Identification of an Impacting System, 2024 UKACC 14th International Conference on Control (CONTROL), DOI:10.1109/control60310.2024.10532098.
- Afebu KO, Tian J, Papatheou E, Liu Y, Prasad S. (2024) A Dynamic Method of Bowel Lesions Characterisation Using Self-Propelled Robotic Capsule and Machine Learning, 2024 UKACC 14th International Conference on Control, CONTROL 2024, pages 145-146, DOI:10.1109/CONTROL60310.2024.10531888.
- Sun Y-H, Dai D-X, Liu Y. (2024) Stochastic analysis and vibration suppression of a time-delayed system with nonlinear energy sink, International Journal of Non-Linear Mechanics, article no. 104750, DOI:10.1016/j.ijnonlinmec.2024.104750.
- Liao Z-J, Sun Y-H, Liu Y. (2024) A viscoelastic nonlinear energy sink with an electromagnetic energy harvester: Narrow-band random response, Chinese Physics B, DOI:10.1088/1674-1056/ad4632. [PDF]
- Zhang Y, Shen J, Yan Y, Tong J, Zhang L, Liu Y. (2024) Enhancing the Mobility of Small-Scale Robots Via Nonlinear Structural Springs Exhibiting Negative Stiffness, Journal of Applied Mechanics, volume 91, no. 8, DOI:10.1115/1.4065339. [PDF]
- Jiang H, Liu Y, Zhang L, Yu J. (2024) Border-collision bifurcation in the Logistic map with state-dependent impulsive forces, Discrete and Continuous Dynamical Systems - Series S, DOI:10.3934/dcdss.2024050.
- Huang M-L, Yang Y-G, Liu Y. (2024) Performance enhancement of a viscoelastic bistable energy harvester using time-delayed feedback control, Chinese Physics B, DOI:10.1088/1674-1056/ad3b89. [PDF]
- Tian B, Yin S, Liu Y, Monsalve JL. (2024) Nonlinear characteristics identification of an impact oscillator with a one-sided elastic constraint, Journal of Sound and Vibration, pages 118270-118270, article no. 118270, DOI:10.1016/j.jsv.2024.118270.
- Yan Y, Guo R, Tian J, Liu Y. (2024) A new capsule-intestine model for the capsule robot self-propelling in the lower gastrointestinal tract, European Journal of Mechanics - A/Solids, pages 105233-105233, article no. 105233, DOI:10.1016/j.euromechsol.2024.105233.
- Wang G, Liu Y, Liu C. (2024) Development of a contact force model with a fluid damping factor for immersed collision events, Chaos Solitons & Fractals, volume 178, DOI:10.1016/j.chaos.2023.114292.
- Tian J, Liu Y, Bi H, Prasad S, Liu C. (2024) Modelling and experimental investigation of capsule-tumour contact for early bowel cancer detection, European Journal of Mechanics - A/Solids, volume 103, DOI:10.1016/j.euromechsol.2023.105148.
- Zhang J, Yin S, Guo B, Liu Y. (2024) Vibro-impact dynamics of an experimental rig with two-sided constraint and bidirectional drift, Journal of Sound and Vibration, volume 571, DOI:10.1016/j.jsv.2023.118021.
- Shi T, Liu Y, Liu Z, Liu C. (2024) Distributions of tension and torsion in a threaded connection, International Journal of Mechanical Sciences, volume 261, DOI:10.1016/j.ijmecsci.2023.108684.
2023
- Zhu J, Liao M, Chavez JP, Liu Y, Li T. (2023) Multi-objective optimization of a self-propelled capsule for small-bowel endoscopy considering the influence of intestinal environment, DOI:10.21203/rs.3.rs-2554989/v1.
- Tian J. (2023) Biomechanics of a Vibro-Impact Capsule Robot Self-Propelling in the Lower Gastrointestinal Tract.
- Bi H, Tian J, Zhang B, Wang B, Liu Y. (2023) Utilisation of a wrinkled film-based structure for the sensing measurement of a vibro-impact capsule robot, Meccanica, volume 58, no. 11, pages 2151-2164, DOI:10.1007/s11012-023-01712-y. [PDF]
- Afebu KO, Tian J, Papatheou E, Liu Y, Prasad S. (2023) Two-stage machine learning models for bowel lesions characterisation using self-propelled capsule dynamics, Nonlinear Dynamics, volume 111, no. 20, pages 19387-19410, DOI:10.1007/s11071-023-08852-6.
- Jiapeng Z, Maolin L, Chávez JP, Yang L, Tingrui L. (2023) Multi-objective optimization of a self-propelled capsule for small bowel endoscopy considering the influence of intestinal environment, Nonlinear Dynamics, volume 111, no. 18, pages 16963-16989, DOI:10.1007/s11071-023-08792-1. [PDF]
- Yin S, Yan Y, Páez Chávez J, Liu Y. (2023) Dynamics of a self-propelled capsule robot in contact with different folds in the small intestine, Communications in Nonlinear Science and Numerical Simulation, volume 126, pages 107445-107445, article no. 107445, DOI:10.1016/j.cnsns.2023.107445. [PDF]
- Zhang J. (2023) Prototype Design and Testing of a Self-Propelled Vibro-Impact Capsule System for Lower Gastrointestinal Endoscopies.
- Tian J, Afebu K, Wang Z, Liu Y. (2023) Dynamic analysis of a soft capsule robot self-propelling in the small intestine via finite element method, Nonlinear Dynamics, DOI:10.1007/s11071-023-08376-z.
- Zhang Z, Páez Chávez J, Sieber J, Liu Y. (2023) Numerical analysis of a multistable capsule system under the delayed feedback control with a constant delay, International Journal of Non-Linear Mechanics, volume 152, pages 104390-104390, DOI:10.1016/j.ijnonlinmec.2023.104390.
- Afebu K, Tian J, Liu Y, Prasad S. (2023) AI-assisted dynamic tissue evaluation for early bowel cancer diagnosis using a vibrational capsule, IEEE Robotics and Automation Letters, volume 8, pages 2341-2348, DOI:10.1109/LRA.2023.3251853.
- Tian J, Afebu KO, Bickerdike A, Liu Y, Prasad S, Nelson BJ. (2023) Fundamentals of Bowel Cancer for Biomedical Engineers, Annals of Biomedical Engineering, volume 51, no. 4, pages 679-701, DOI:10.1007/s10439-023-03155-8.
- Zhang J, Liu Y, Tian J, Zhu D, Prasad S. (2023) Design and Experimental Investigation of a Vibro-Impact Capsule Robot for Colonoscopy, IEEE Robotics and Automation Letters, volume 8, no. 3, pages 1842-1849, DOI:10.1109/lra.2023.3243804. [PDF]
- Wang G, Ma D, Liu C, Liu Y. (2023) Development of a compliant dashpot model with nonlinear and linear behaviors for the contact of multibody systems, Mechanical Systems and Signal Processing, volume 185, pages 109785-109785, article no. 109785, DOI:10.1016/j.ymssp.2022.109785. [PDF]
2022
- Liu Y, Chernousko FL, Terry BS, Páez Chávez J. (2022) Special issue on self-propelled robots: from theory to applications, Meccanica, volume 58, no. 2-3, pages 317-319, DOI:10.1007/s11012-022-01631-4.
- Liu Y, Tian J, Guo B, Prasad S. (2022) Chapter 10 Modeling of capsule-intestine contact, Endorobotics, Elsevier, 241-255, DOI:10.1016/b978-0-12-821750-4.00010-4.
- Yan Y, Guo B, Tian J, Zhang J, Zhang B, Ley E, Liu Y, Prasad S. (2022) Evaluating the resistant force of an endoscopic capsule self-propelling in the small intestine, Archive of Applied Mechanics, volume 92, no. 12, pages 3861-3875, DOI:10.1007/s00419-022-02267-2. [PDF]
- Yin S, Yan Y, Páez Chávez J, Liu Y. (2022) Bifurcation analysis of a vibro-impacting capsule robot in contact with a circular fold, Physica D: Nonlinear Phenomena, volume 442, pages 133524-133524, article no. 133524, DOI:10.1016/j.physd.2022.133524. [PDF]
- Wang G, Ma D, Liu Y, Liu C. (2022) Research progress of contact force models in the collision mechanics of multibody system, Chinese Journal of Theoretical and Applied Mechanics, volume 54, pages 1-28, DOI:10.6052/0459-1879-22-266.
- Yan Y, Zhang B, Páez Chávez J, Liu Y. (2022) Optimising the locomotion of a vibro-impact capsule robot self-propelling in the small intestine, Communications in Nonlinear Science and Numerical Simulation, volume 114, pages 106696-106696, article no. 106696, DOI:10.1016/j.cnsns.2022.106696. [PDF]
- Afebu KO, Liu Y, Papatheou E. (2022) Machine learning-based rock characterisation models for rotary-percussive drilling, Nonlinear Dynamics, volume 109, pages 1-21, DOI:10.1007/s11071-022-07565-6.
- Zhang J, Liu Y, Zhu D, Prasad S, Liu C. (2022) Simulation and experimental studies of a vibro-impact capsule system driven by an external magnetic field, Nonlinear Dynamics, volume 109, no. 3, pages 1501-1516, DOI:10.1007/s11071-022-07539-8.
- Zhang L-P, Liu Y, Wei Z-C, Jiang H-B, Lyu W-P, Bi Q-S. (2022) Extremely hidden multi-stability in a class of two-dimensional maps with a cosine memristor, Chinese Physics B, volume 31, no. 10, DOI:10.1088/1674-1056/ac7294.
- Yan Y, Zhang B, Liu Y, Prasad S. (2022) Dynamics of a vibro-impact self-propelled capsule encountering a circular fold in the small intestine, Meccanica, volume 58, no. 2-3, pages 451-472, DOI:10.1007/s11012-022-01528-2. [PDF]
- Wang G, Liu C, Liu Y. (2022) Energy Dissipation Analysis for Elastoplastic Contact and Dynamic Dashpot Models, International Journal of Mechanical Sciences, volume 221, pages 107214-107214, article no. 107214, DOI:10.1016/j.ijmecsci.2022.107214. [PDF]
- Zhang J, Tian J, Zhu D, Liu Y, Prasad S. (2022) Design and experimental investigation of a vibro-impact self-propelled capsule robot with orientation control, 2022 IEEE International Conference on Robotics and Automation (ICRA), 23rd - 27th May 2022, 2022 International Conference on Robotics and Automation (ICRA), DOI:10.1109/icra46639.2022.9812117. [PDF]
- Liao M, Zhang J, Liu Y, Zhu D. (2022) Speed optimization and reliability analysis of a self-propelled capsule robot moving in an uncertain frictional environment, International Journal of Mechanical Sciences, volume 221, pages 107156-107156, article no. 107156, DOI:10.1016/j.ijmecsci.2022.107156.
- Zhang L, Liu Y, Wei Z, Jiang H, Bi Q. (2022) Hidden attractors in a class of two-dimensional rational memristive maps with no fixed points, European Physical Journal: Special Topics, volume 231, no. 11-12, pages 2173-2182, DOI:10.1140/epjs/s11734-022-00483-z.
- Afebu KO. (2022) Intelligent models for optimisation of the vibro-impact drilling system.
- Liu Y, Tian J, Manfredi L, Terry B, Prasad S, Rahman I, Marlicz W, Koulaouzidis A. (2022) A survey of small bowel modelling and its applications for capsule endoscopy, Mechatronics, volume 83, pages 102748-102748, DOI:10.1016/j.mechatronics.2022.102748.
- Afebu K, Liu Y, Papatheou E. (2022) Feature-based intelligent models for optimisation of percussive drilling, Neural Networks, volume 148, pages 266-284, DOI:10.1016/j.neunet.2022.01.021.
- Zhang Z. (2022) Control of Coexisting Attractors in Nonsmooth Dynamical Systems.
2021
- Tian J, Liu Y, Prasad S. (2021) Exploring the Dynamics of a Vibro-Impact Capsule Moving on the Small Intestine Using Finite Element Analysis, NODYCON Conference Proceedings Series, Springer International Publishing, 127-136, DOI:10.1007/978-3-030-81170-9_12. [PDF]
- Zhang Z, Páez Chávez J, Sieber J, Liu Y. (2021) Controlling coexisting attractors of a class of non-autonomous dynamical systems, Physica D: Nonlinear Phenomena, volume 431, DOI:10.1016/j.physd.2021.133134.
- Zhang L-P, Liu Y, Wei Z-C, Jiang H-B, Bi Q-S. (2021) A new class of two-dimensional rational maps with self-excited and hidden attractors, Chinese Physics B, DOI:10.1088/1674-1056/ac4025.
- Liu Y, Páez Chávez J, Brzeski P, Perlikowski P. (2021) Dynamical response of a rocking rigid block, Chaos: An Interdisciplinary Journal of Nonlinear Science, volume 31, no. 7, pages 073136-073136, DOI:10.1063/5.0040962.
- Tian J, Liu Y, Chen J, Guo B, Prasad S. (2021) Finite element analysis of a self-propelled capsule robot moving in the small intestine, International Journal of Mechanical Sciences, volume 206, pages 106621-106621, article no. 106621, DOI:10.1016/j.ijmecsci.2021.106621.
- Guo B, Páez Chávez J, Liu Y, Liu C. (2021) Discontinuity-induced bifurcations in a piecewise-smooth capsule system with bidirectional drifts, Communications in Nonlinear Science and Numerical Simulation, volume 102, pages 105909-105909, article no. 105909, DOI:10.1016/j.cnsns.2021.105909. [PDF]
- Zhang Z, Páez Chávez J, Sieber J, Liu Y. (2021) Controlling grazing-induced multistability in a piecewise-smooth impacting system via the time-delayed feedback control, Nonlinear Dynamics, volume 107, no. 2, pages 1595-1610, DOI:10.1007/s11071-021-06511-2.
- Afebu KO, Liu Y, Papatheou E. (2021) Application and comparison of feature-based classification models for multistable impact motions of percussive drilling, Journal of Sound and Vibration, volume 508, pages 116205-116205, article no. 116205, DOI:10.1016/j.jsv.2021.116205.
- Afebu K, Liu Y, Papatheou E, Guo B. (2021) LSTM-based approach for predicting periodic motions of an impacting system via transient dynamics, Neural Networks, volume 140, pages 49-64, DOI:10.1016/j.neunet.2021.02.027.
- Zhang L, Jiang H, Liu Y, Wei Z, Bi Q. (2021) Controlling hidden dynamics and multi-stability of a class of two-dimensional maps via linear augmentation, International Journal of Bifurcation and Chaos, volume 31, pages 2150047-2150047, DOI:10.1142/S0218127421500474.
2020
- Liu Y, Páez Chávez J, Zhang J, Tian J, Guo B, Prasad S. (2020) The vibro-impact capsule system in millimetre scale: numerical optimisation and experimental verification, Meccanica, volume 55, no. 10, pages 1885-1902, DOI:10.1007/s11012-020-01237-8.
- Guo B, Ley E, Tian J, Zhang J, Liu Y, Prasad S. (2020) Experimental and numerical studies of intestinal frictions for propulsive force optimisation of a vibro-impact capsule system, Nonlinear Dynamics, volume 101, no. 1, pages 65-83, DOI:10.1007/s11071-020-05767-4. [PDF]
- Huang K, Yang Y, Liu Y, Niu Q. (2020) Vibration failure and anti-vibration analysis of an annular-grooved PDC bit, Engineering Failure Analysis, volume 115, pages 104658-104658, article no. 104658, DOI:10.1016/j.engfailanal.2020.104658.
- Huang K, Yang Y, Liu Y, Zhong Y, Ren H. (2020) Study on rock breaking mechanism of PDC bit with rotating module, Journal of Petroleum Science and Engineering, volume 192, DOI:10.1016/j.petrol.2020.107312.
- Liu Y, Páez Chávez J, Guo B, Birler R. (2020) Bifurcation analysis of a vibro-impact experimental rig with two-sided constraint, Meccanica, volume 55, pages 2505-2521, DOI:10.1007/s11012-020-01168-4.
- Zhang L-P, Liu Y, Wei Z-C, Jiang H-B, Bi Q-S. (2020) A novel class of two-dimensional chaotic maps with infinitely many coexisting attractors*, Chinese Physics B, volume 29, no. 6, pages 060501-060501, DOI:10.1088/1674-1056/ab8626. [PDF]
- Zhang Z, Liu Y, Sieber J. (2020) Calculating the Lyapunov exponents of a piecewise-smooth soft impacting system with a time-delayed feedback controller, Communications in Nonlinear Science and Numerical Simulation, volume 91, pages 105451-105451, article no. 105451, DOI:10.1016/j.cnsns.2020.105451.
- Guo B, Liu Y, Birler R, Prasad S. (2020) Self-propelled capsule endoscopy for small-bowel examination: proof-of-concept and model verification, International Journal of Mechanical Sciences, volume 174, pages 105506-105506, DOI:10.1016/j.ijmecsci.2020.105506. [PDF]
- Lin W, Páez Chávez J, Liu Y, Yang Y, Kuang Y. (2020) Stick-slip suppression and speed tuning for a drill-string system via proportional-derivative control, Applied Mathematical Modelling, volume 82, pages 487-502, DOI:10.1016/j.apm.2020.01.055.
2019
- Kuang Y, Lin W, Liu Y, Wang Q, Zhang J. (2019) Numerical modelling and field experimental validation of the axial load transfer on the drill-strings in deviated wells, Journal of Natural Gas Science and Engineering, volume 75, pages 103124-103124, article no. 103124, DOI:10.1016/j.jngse.2019.103124.
- Shi T, Liu Y, Wang N, Liu C. (2019) Toppling dynamics of a mass-varying domino system, Nonlinear Dynamics, volume 98, no. 3, pages 2261-2275, DOI:10.1007/s11071-019-05324-8. [PDF]
- Páez Chávez J, Zhang Z, Liu Y. (2019) A numerical approach for the bifurcation analysis of nonsmooth delay equations, Communications in Nonlinear Science and Numerical Simulation, volume 83, pages 105095-105095, article no. 105095, DOI:10.1016/j.cnsns.2019.105095.
- Liu Y, Guo B, Prasad S. (2019) Resonance enhanced self-propelled capsule endoscopy for small bowel examination, Gut, volume 68, pages A31-A31, DOI:10.1136/gutjnl-2019-BSGAbstracts.63.
- Liu Y, Lin W, Páez Chávez J, De Sa R. (2019) Torsional stick-slip vibrations and multistability in drill-strings, Applied Mathematical Modelling, volume 76, DOI:10.1016/j.apm.2019.06.012.
- Guo B, Liu Y, Prasad S. (2019) Modelling of capsule–intestine contact for a self-propelled capsule robot via experimental and numerical investigation, Nonlinear Dynamics, volume 98, no. 4, pages 3155-3167, DOI:10.1007/s11071-019-05061-y.
- Guo B, Liu Y. (2019) Three-dimensional map for a piecewise-linear capsule system with bidirectional drifts, Physica D: Nonlinear Phenomena, volume 399, pages 95-107, DOI:10.1016/j.physd.2019.04.008.
- Jiang H, Liu Y, Wei Z, Zhang L. (2019) A New Class of Two-dimensional Chaotic Maps with Closed Curve Fixed Points, International Journal of Bifurcation and Chaos, volume 29, pages 1950094-1-1950094-10, DOI:10.1142/S0218127419500949.
- Yan Y, Liu Y, Manfredi L, Prasad S. (2019) Modelling of a Vibro-Impact Self-Propelled Capsule in the Small Intestine, Nonlinear Dynamics, volume 96, pages 123-144, DOI:10.1007/s11071-019-04779-z.
- Yan Y, Liu Y, Jiang H, Peng Z, Crawford A, Williamson J, Thomson J, Kerins G, Yusupov A, Islam S. (2019) Optimization and experimental verification of the vibro-impact capsule system in fluid pipeline, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, volume 233, no. 3, pages 880-894, DOI:10.1177/0954406218766200.
2018
- Liao M, Liu Y, Páez Chávez J, Chong A, Wiercigroch M. (2018) Dynamics of vibro-impact drilling with linear and nonlinear rock models, International Journal of Mechanical Sciences, volume 146-147, pages 200-210, DOI:10.1016/j.ijmecsci.2018.07.039.
- Zhang L, Jiang H, Liu Y. (2018) Bifurcation Analysis of a Rigid Impact Oscillator with Bilinear Damping, Shock and Vibration, volume 2018, DOI:10.1155/2018/1617650.
- Liu Y, Páez Chávez J, Pavlovskaia E, Wiercigroch M. (2018) Analysis and control of the dynamical response of a higher order drifting oscillator, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 474, DOI:10.1098/rspa.2017.0500.
- Shi T, Liu Y, Wang N, Liu C. (2018) Toppling dynamics of regularly spaced dominoes in an array, Journal of Applied Mechanics.
- Liu Y. (2018) Control of a class of multibody underactuated mechanical systems with discontinuous friction using sliding-mode, Transactions of the Institute of Measurement and Control, volume 40, no. 2, pages 514-527, DOI:10.1177/0142331216661759.
2017
- Yan Y, Liu Y, Páez Chávez J, Zonta F, Yusupov A. (2017) Proof-of-Concept Prototype Development of the Self-Propelled Capsule System for Pipeline Inspection, Meccanica, volume 53, pages 1997-2012, DOI:10.1007/s11012-017-0801-3.
- Liu Y, Paez Chavez J, De Sa R, Walker S. (2017) Numerical and experimental studies of stick-slip oscillations in drill-strings, Nonlinear Dynamics, volume 90, pages 2959-2978, DOI:10.1007/s11071-017-3855-9.
- Yan Y, Liu Y, Liao M. (2017) A Comparative Study of the Vibro-Impact Capsule Systems with One-Sided and Two-Sided Constraints, Nonlinear Dynamics, volume 89, pages 1063-1087, DOI:10.1007/s11071-017-3500-7.
- Liu Y, Páez Chávez J. (2017) Controlling coexisting attractors of an impacting system via linear augmentation, Physica D: Nonlinear Phenomena, volume 348, pages 1-11, DOI:10.1016/j.physd.2017.02.018.
- Liu Y, Páez Chávez J. (2017) Controlling Multistability in a Vibro-Impact Capsule System, Nonlinear Dynamics, volume 88, pages 1289-1304, DOI:10.1007/s11071-016-3310-3.
2016
- Jiang H, Liu Y, Wei Z, Zhang L. (2016) A New Class of Three-Dimensional Maps with Hidden Chaotic Dynamics, International Journal of Bifurcation and Chaos, volume 26, no. 12, DOI:10.1142/S0218127416502060.
- Jiang H, Liu Y, Wei Z, Zhang L. (2016) Hidden chaotic attractors in a class of two-dimensional maps, Nonlinear Dynamics, volume 85, no. 4, pages 2719-2727, DOI:10.1007/s11071-016-2857-3. [PDF]
- Páez Chávez J, Liu Y, Pavlovskaia E, Wiercigroch M. (2016) Path-following analysis of the dynamical response of a piecewise-linear capsule system, Communications in Nonlinear Science and Numerical Simulation, volume 37, pages 102-114, DOI:10.1016/j.cnsns.2016.01.009. [PDF]
- Liu Y, Islam S, Pavlovskaia E, Wiercigroch M. (2016) Optimization of the Vibro-Impact Capsule System, Strojniški vestnik - Journal of Mechanical Engineering, volume 62, no. 7-8, pages 430-439, DOI:10.5545/sv-jme.2016.3754. [PDF]
- Jiang H, Liu Y, Zhang L, Yu J. (2016) Anti-phase synchronization and symmetry-breaking bifurcation of impulsively coupled oscillators, Communications in Nonlinear Science and Numerical Simulation, volume 39, pages 199-208, DOI:10.1016/j.cnsns.2016.02.033. [PDF]
2015
- Liu Y. (2015) Suppressing stick‐slip oscillations in underactuated multibody drill‐strings with parametric uncertainties using sliding‐mode control, IET Control Theory & Applications, volume 9, no. 1, pages 91-102, DOI:10.1049/iet-cta.2014.0329. [PDF]
- Liu Y, Pavlovskaia E, Wiercigroch M, Peng Z. (2015) Forward and backward motion control of a vibro-impact capsule system, International Journal of Non-Linear Mechanics, volume 70, pages 30-46, DOI:10.1016/j.ijnonlinmec.2014.10.009. [PDF]
- Liu Y, Pavlovskaia E, Wiercigroch M. (2015) Experimental verification of the vibro-impact capsule model, Nonlinear Dynamics, volume 83, no. 1-2, pages 1029-1041, DOI:10.1007/s11071-015-2385-6. [PDF]
2013
- Liu Y, Pavlovskaia E, Hendry D, Wiercigroch M. (2013) Vibro-impact responses of capsule system with various friction models, International Journal of Mechanical Sciences, volume 72, pages 39-54, DOI:10.1016/j.ijmecsci.2013.03.009. [PDF]
- Liu Y, Wiercigroch M, Ing J, Pavlovskaia E. (2013) Intermittent control of coexisting attractors, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, volume 371, no. 1993, pages 20120428-20120428, DOI:10.1098/rsta.2012.0428. [PDF]
- Liu Y, Yu H. (2013) A survey of underactuated mechanical systems, IET Control Theory & Applications, volume 7, no. 7, pages 921-935, DOI:10.1049/iet-cta.2012.0505.
- Liu Y, Wiercigroch M, Pavlovskaia E, Yu H. (2013) Modelling of a vibro-impact capsule system, International Journal of Mechanical Sciences, volume 66, pages 2-11, DOI:10.1016/j.ijmecsci.2012.09.012. [PDF]
2012
- Liu Y, Yu H. (2012) Fuzzy control of an underactuated pendulum-driven cart system, International Journal of Advanced Mechatronic Systems, volume 4, no. 5/6, pages 260-260, DOI:10.1504/ijamechs.2012.052221. [PDF]
2011
- Liu Y, Yu H, Cang S. (2011) Modelling and motion control of a double-pendulum driven cart, Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, volume 226, no. 2, pages 175-187, DOI:10.1177/0959651811414507. [PDF]
2010
- Liu Y, Hasan MS, Yu H-N. (2010) Modelling and remote control of an excavator, International Journal of Automation and Computing, volume 7, no. 3, pages 349-358, DOI:10.1007/s11633-010-0514-8. [PDF]
- Yu H, Liu Y, Hasan MS. (2010) Review of modelling and remote control for excavators, International Journal of Advanced Mechatronic Systems, volume 2, no. 1/2, pages 68-68, DOI:10.1504/ijamechs.2010.030850. [PDF]
2009
- Liu Y, Yu H. (2009) Variable structure control of a capsule robot system, Proceedings of the 2009 IEEE International Conference on Networking, Sensing and Control, ICNSC 2009, pages 220-226, DOI:10.1109/ICNSC.2009.4919276.
2008
- Liu Y, Yu H, Yang TC. (2008) Analysis and Control of a Capsubot, IFAC-PapersOnLine, volume 41, no. 2, pages 756-761, DOI:10.3182/20080706-5-kr-1001.00130.
- Yu H, Yang T, Liu Y, Wane S. (2008) A further study of control for a pendulum-driven cart, International Journal of Advanced Mechatronic Systems, volume 1, no. 1, pages 44-44, DOI:10.1504/ijamechs.2008.020837. [PDF]
- Yu H, Liu Y, Yang T. (2008) Closed-loop tracking control of a pendulum-driven cart-pole underactuated system, Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, volume 222, no. 2, pages 109-125, DOI:10.1243/09596518jsce460. [PDF]
- Liu Y, Yu H, Wane S, Yang T. (2008) On tracking control of a pendulum-driven cart-pole underactuated system, International Journal of Modelling, Identification and Control, volume 4, no. 4, pages 357-357, DOI:10.1504/ijmic.2008.021476. [PDF]
2007
- Hongnian Yu, Yang Liu, Tai Yang. (2007) Tracking control of a pendulum-driven cart-pole underactuated system, 2007 IEEE International Conference on Systems, Man and Cybernetics, 7th - 10th Oct 2007, 2007 IEEE International Conference on Systems, Man and Cybernetics, DOI:10.1109/icsmc.2007.4413859. [PDF]
Patents
- Wiercigroch M, Liu Y. Control Method, Patent Number: US20160245064 A1, 2016. [PDF]
- Huda M, Yu H, Liu Y, Wane S. Travelling Capsule with Two Drive Mechanisms, Patent Number: GB Patent 2497544, 2013. [PDF]
Further information
Team Members
Consultant Clinicians:
- Dr Shyam Prasad, Lead Clinician for Gastroenterology at the Royal Devon University Healthcare NHS Foundation Trust
- Prof. Anastasios Koulaouzidis, Clinical Professor, University of Southern Denmark, Denmark
Postdoctoral Research Fellows/Associates:
- Dr Kenneth Omokhagbo Afebu, MRC knowledge exchange fellow, since September 2021
- Dr Yahui Sun, Marie Skłodowska-Curie individual fellow, since October 2023
- Dr Gengxiang Wang, Marie Skłodowska-Curie individual fellow, since October 2023
PhD Students (Primary Supervisor):
- Mr Xizheng Fang, since Sep 2023
- Mr Siyuan Wang, since Sep 2023
- Mr Andrew Bickerdike, On the piecewise-smooth dynamics of robot-cancer interaction at microscale, since Sep 2021
- Mr Bo Tian, Design and optimization of micro-robots moving in the gut for biopsy, since Sep 2021
- Mr Zepeng Wang, Design of a proof-of-concept vibro-impact capsule system for medical diagnosis and therapy, since Nov 2020
- Mr Ahmed Al Shekaili, Numerical and experimental investigation of drill-string dynamics for oil and gas drilling, since Sep 2019
Visiting Scholars:
- N/A
PhD Graduates:
-
Dr Zhi Zhang, Postdoctoral research associate at Newcastle University (UK)
- Thesis title: Control of coexisting attractors in nonsmooth dynamical systems, August 2021
-
Dr Kenneth Omokhagbo Afebu, MRC knowledge exchange fellow at the University of Exeter
- Thesis title: Intelligent models for optimisation of the vibro-impact drilling system, August 2021
-
Dr Jiajia Zhang, Electrical engineer, Hunter Stoves (UK)
- Thesis title: Prototype design and testing of a self-propelled vibro-impact capsule system for lower gastrointestinal endoscopies, May 2023
-
Dr Jiyuan Tian, German Cancer Research Center (Germany)
- Thesis title: Biomechanics of a vibro-impact capsule robot self-propelling in the lower gastrointestinal tract, October 2023
Former Postdocs:
- Prof. Bingyong Guo, Professor at Northwestern Polytechnical University (China)
- Dr Shan Yin, Marie Skłodowska-Curie individual fellow, since October 2021
Former Visiting Scholars:
- Mr Wei Lin (CSC Visiting Scholar), School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
- Dr Xiaojun Dai (CSC Visiting Scholar), School of Civil Engineering and Architecture, Southwest Petroleum University, Chengdu, China
- Dr Kuilin Huang, School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
- Dr Shiwei Niu, School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
- Mr Yiwei Han (CSC Visiting Scholar), School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
- Prof. Yundong Li (CSC Visiting Scholar), School of Mathematics and Statistics, Sichuan University of Science and Engineering, Zigong, China
- Dr Feng Zhou (CSC Visiting Scholar), School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu, China
- Miss Shuning Deng (CSC Visiting PhD Student), State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China
- Mr Haohao Bi (CSC Visiting PhD Student), Department of Applied Mathematics, Northwestern Polytechnical University, Xi'an, China
- Mr Zhao Tan (CSC Visiting PhD Student), State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China
Open Positions
Open Positions:
- CSC PhD Scholarships for September 2024/25 Entry (Deadline: 1 January 2024)
Closed Positions:
-
Marie Skłodowska-Curie Actions Postdoctoral Fellowship 2023 (Deadline: 13 September 2023)
-
EPSRC DTP PhD Studentships for September 2023 (Deadline: 27 February 2023)
- CSC PhD Scholarships for September 2023/24 Entry (Deadline: 4 January 2023)
-
EPSRC Funded Studentships for September 2022 Entry (Ref: 4345)
-
EPSRC Mathematical Sciences DTP Funded Studentship (Ref: 4172) for September 2021 Entry (Application Deadline: 30 July 2021)
-
Development of Next Generation of Smart Electric Fire Stoves (EPSRC CDT in Sustainable Materials and Manufacturing, Ref: 3618) (Application Deadline: Wednesday 23rd September 2019)
-
EPSRC DTP Funded PhD Studentship (Ref: 3389) - Modelling and experimental study of capsule locomotion in the small intestine for endoscopic diagnosis (Application Deadline: 7th January 2019)
-
Prototype Design of the Self-Propelled Vibro-Impact Capsule System for Small Intestinal Endoscopy, ENG – PhD (Funded, International candiates welcome) Ref: 2869 (Application Deadline: 28 February 2018)
- China Scholarship Council (CSC) funded candidates may discuss PhD opportunities with Dr Liu directly via email. Ref: 2817 (Application Deadline: 29 January 2018)
-
Prototype Design of the Self-Propelled Vibro-Impact Capsule System for Large Bowel Endoscopy, ENG – PhD (Funded, UK/EU candidates only) Ref: 2884 (Application Deadline: 10 January 2018)
- Engineering Fully-Funded PhD Studentship (Application Deadline: 23rd April 2017): Ref: 2390
-
Postdoctoral Research Fellow Position (18 months) (Application Deadline: 17th August 2017): Ref: P57189
I am offering to supervise self-funded PhD students in the areas of
- Gastrointestinal endoscopy: mechanical, electrical design, prototyping, ex- and in-vivo tests;
- Micro-robots: modelling, design and testing;
- Non-smooth dynamical systems: modelling, bifurcation analysis and control;
- Pipeline inspection robot: mechanical and electrical design, prototyping and testing.
Collaborators
Academic:
- Prof. Joseph Páez Chávez, Department of Mathematics, Faculty of Natural Sciences and Mathematics, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
- Prof. Caishan Liu, College of Engineering, Peking University, Beijing, China
- Prof. Yao Yan, School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu, China
- Prof. Maolin Liao, School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
- Prof. Bradley J. Nelson, Multi-Scale Robotics Lab, ETH Zürich, Zürich, Switzerland
- Prof. Kevin Chen, Soft and Micro Robotics Laboratory, MIT, Boston, USA
Clinical Advisors:
- Dr Shyam Prasad, Endoscopy Department, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
- Prof. Anastasios Koulaouzidis, Centre for Clinical Implementation of Capsule Endoscopy, University of Southern Denmark, Odense, Denmark
Seminars
Date and Time: 13:30 - 14:30, Wednesday 6 March 2024
Venue: Harrison 215
Speaker: Mr James Clark, Consultant Gastrointestinal Surgeon, Royal Cornwall Hospital NHS Trust
Title: Tomorrows Surgery "The future belongs to those who prepare for it today"
=============================================
Date and Time: 11:00 - 12:00, Monday 5 June 2023
Venue: Harrison 170
Speaker: Prof. Kevin Chen, Assistant Professor, Department of Electrical Engineering and Computer Science, MIT, USA
Title: Agile, robust, and multifunctional micro-aerial-robots powered by soft artificial muscles
Abstract: Recent advances in microrobotics have demonstrated remarkable locomotive capabilities such as hovering flights, impulsive jumps, and fast running in insect-scale robots. However, most microrobots that are powered by power-dense rigid actuators have not achieved insect-like collision resilience. In this talk, I will present our recent effort in developing a new class of microrobots – ones that are powered by high bandwidth soft actuators and equipped with rigid appendages for effective interactions with environments. Towards improving collision robustness of micro-aerial robots, we develop the first heavier-than-air aerial robot powered by soft artificial muscles that demonstrates a 40-second hovering flight. In addition, our robot can recover from an in-flight collision and perform a somersault within 0.16 seconds. The robot’s maximum lift is comparable to that of the best rigid-powered sub-gram robots. This work demonstrates for the first time that soft aerial robots can achieve agile and robust flight capabilities absent in rigid-powered micro-aerial vehicles, thus showing the potential of a new class of hybrid soft-rigid robots.
=============================================
Date and Time: 14:00 - 15:00 BST, Wednesday 28 September 2022
Venue: Zoom
Speaker: Prof. Katia Bertoldi, William and Ami Kuan Danoff Professor of Applied Mechanics, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
Title: Functionality through multistability in metamaterials: from soft robots to deployable structures
Abstract: Inflating a rubber balloon leads to a dramatic shape change: a property that is exploited in the design of soft robots and deployable structures. On the one hand, fluid-driven actuators capable of complex motion can power highly adaptive and inherently safe soft robots. On the other hand, inflation can be used to transform seemingly flat shapes into shelters, field hospitals, and space modules. In both cases, just like the simple balloon, only one input is required to achieve the desired deformation. This simplicity, however, brings strict limitations: soft actuators are often restricted to unimodal and slow deformation and deployable structures need a continuous supply of pressure to remain upright. Here, we embrace multistability as a paradigm to improve the functionality of inflatable systems. In the first part of this seminar, I exploit snapping instabilities in spherical shells to decouple the input signal from the output deformation in soft actuators – a functionality that can be utilized to design a soft machine capable of jumping. In the second part of the seminar, I draw inspiration from origami to design multistable and inflatable structures at the meter scale. Because these deployable systems are multistable, pressure can be disconnected when they are fully expanded, making them ideal candidates for applications such as emergency sheltering and deep space exploration. Together, these two projects highlight the potential of multistability in enabling the design and fabrication across various scales of multi-form, multi-functional, and multi-purpose materials and structures.
=============================================
Date and Time: 13:30 - 14:30 BST, Monday 1 August 2022
Venue: Harrison 250 + Zoom
Speaker: Prof. Moi Hoon Yap, Professor of Image and Vision Computing, Department of Computing and Mathematics, Manchester Metropolitan University, Manchester, UK
Title: Diabetic foot ulcers detection and monitoring: the next generation tools for clinical settings
Abstract: This talk provides conceptual foundation and procedures used in the development of diabetic foot ulcer (DFU) datasets over the past decade, with a timeline to demonstrate progress. It covers data capturing methods for foot photographs, an overview of research in developing private and public datasets, the related computer vision tasks (detection, segmentation and classification), the diabetic foot ulcer challenges and the future direction of the development of the datasets. As leading institution and investigator in this field, my aim is to share the technical challenges that we encountered together with good practices in dataset development, and provide motivation for other researchers to participate in data sharing in this domain. Future research involves call for effort in establishing international consortium to form international repository of DFU research. For more details, please refer to https://dfu-challenge.github.io/
=============================================
Date and Time: 13:00 - 14:00 BST, Friday 24 June 2022
Venue: Zoom
Speaker: Dr Jamie Marland, Lecturer in Microelectronics, School of Engineering, University of Edinburgh, UK
Title: Measuring tissue oxygenation using microfabricated implantable sensors
Abstract: Tissue oxygenation is of central importance in human health and disease. We have developed a series of miniature implantable electrochemical sensors that allow oxygen to be monitored in a range of medical applications. In this seminar, I will discuss the sensor microfabrication and packaging, and then move on to describe in vivo pre-clinical testing in two important clinical applications: tumour hypoxia, and post-operative monitoring following colorectal surgery. The technical challenges of implantable sensing will also be discussed, including methods for mitigating biofouling.
=============================================
Date and Time: 13:30 - 14:30, Thursday 28 April 2022
Venue: Harrison 215
Speaker: Prof. Grzegorz Litak, Professor, Lublin University of Technology, Lublin, Poland
Title: Broadband Vibration Energy Harvesting
Abstract: Energy harvesting by coupled mistuned oscillators is analysed. The ambient energy source to the system is considered in the form of harmonic base excitations. High-energy orbit harvesting by bifurcation diagrams, phase portraits, and Fourier spectra. The results indicate various periodic, quasiperiodic and also chaotic solutions. Finally, cross recurrence plots are applied to show synchronization states in a connection of the total power output.
=============================================
Date and Time: 13:30 - 14:30, Thursday 28 April 2022
Venue: Harrison 215
Speaker: Prof. Damian Gaska, Associate Professor, Silesian University of Technology, Katowice, Poland
Title: Selected Nonlinear Systems in Mechanical Engineering
Abstract: The presentation will cover issues related to the results of model tests of various mechanical structures in which the energy potential is characterized by appropriately connected elastic and dissipative elements with a variable configuration. Numerical simulation experiments were carried out to assess the impact of physical properties and initial conditions on the occurrence of coexisting solutions. To be able to choose the best solution in terms of energy efficiency, studies considering the issue related to the assessment of the disturbing impulse for the possibility of correction of the phase trajectory will be also presented.
=============================================
Date and Time: 13:00 - 14:00, Wednesday 19 January 2022
Venue: Zoom (Join Zoom Meeting)
Speaker: Mr Haohao Bi, CSC visiting PhD student, Department of Applied Mathematics, Northwestern Polytechnical University, Xi'an, China
Title: Static buckling behaviours and nonlinear dynamic analysis for a corrugated thin film on a pre-strained bi-layer substrate
Abstract: Bonding a thin stiff film on a pre-strained soft substrate to form a wavy configuration shape has been widely used to fabricate stretchable electronic devices. An intermediate layer between a thin stiff film and a substrate can enhance the adhesion of the film and modulate its buckling shape. Capturing buckling behaviours of the tri-layer film/intermediate layer/substrate structure and improving the robustness of this structure are essential for designing stretchable electronics. In this talk, an improved theoretical model of the buckled tri-layer structure is established. Then the governing equation of motion of this structure is derived, based on the geometrical homogenization theory. By using the Jacobi elliptic function, the analytical nonlinear frequency of the tri-layer structure with corrugated film is obtained. Finally, numerical examples are analysed to reveal the influences of the Young's modulus and thickness of the intermediate layer on the nonlinear frequency of the corrugated tri-layer structure. These results are helpful for the design of reliable film/substrate-type stretchable electronic devices.
=============================================
Date and Time: 13:00 - 14:00, Wednesday 8 December 2021Venue: Zoom (Join Zoom Meeting)
Speaker: Dr Ali K. Hoshiar, Assistant Professor, School of Computer Science and Electronic Engineering, University of Essex, UK
Title: Recent developments on microrobotic systems for swarm delivery of the therapeutics agents
Abstract: The rapid advancement in microrobotic systems in recent years for the medical applications, as well as human scale microrobotics systems, and advancements in the medical monitoring systems (magnetic particle imaging (MPI), fast MRI, and X-ray) lead to the precise control of microswarms in therapeutic delivery applications. However, predicting the nonlinear complex behaviour of the microswarms in the magnetic field remained as an open challenge. In this talk I will present the recent monitoring schemes (e.g., MPI), the practical actuation schemes, and most recent predictive models for microswarm control.
=============================================
Date and Time: 13:30 - 14:30, Wednesday 3 November 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Professor Cunjia Liu, Reader in Unmanned Vehicles, Department of Aeronautical and Automotive Engineering, Loughborough University, UK
Title: Autonomous search of atmospheric CBR release using mobile robotics: From estimation to path planning
Abstract: In the event of unexpected release of Chemical, Biological and Radiological (CBR) substances into atmosphere, it is of critical importance to identify the source of the release and capture its possible dispersion. This talk will introduce a set of information theoretic approaches that can be used to guide a mobile robot platform to autonomously search the environment and characterise the source term of the airborne hazardous materials. An outline of the information theoretic framework for reconstructing the release term will be discussed, which will be followed by some case studies of deploying autonomous robotics to respond to chemical release incidents.
=============================================
Date and Time: 12:30 - 13:30, Friday 10 September 2021
Venue: Harrison 170 or Zoom (Join Zoom Meeting)
Speaker: Prof. Pietro Valdastri, Professor and Chair in Robotics and Autonomous Systems, School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK
Title: Medical capsule robots: a fantastic voyage
Abstract: At the beginning of the new millennia, wireless capsule endoscopy was introduced as a minimally invasive method of inspecting the digestive tract. The possibility of collecting images deep inside the human body just by swallowing a “pill” revolutionized the field of gastrointestinal endoscopy and sparked a brand-new field of research in robotics: medical capsule robots. These are self-contained robots that leverage extreme miniaturization to access and operate in environments that are out of reach for larger devices. In medicine, capsule robots can enter the human body through natural orifices or small incisions, and detect and cure life-threatening diseases in a non-invasive manner. This talk will provide a perspective on how this field has evolved in the last ten year. We will explore what was accomplished, what has failed, and what were the lessons learned. We will also discuss enabling technologies, intelligent control, possible levels of computer assistance, and highlight future challenges in this ongoing Fantastic Voyage.
=============================================
Date and Time: 13:30 - 14:30, Friday 16 July 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Mr Jiyuan Tian, PhD candidate, College of Engineering, Mathematics and Physical Sciences, University of Exeter
Title: Exploring the dynamics of a vbro-impact capsule moving on the small intestine using finite element analysis
Abstract: This talk aims to study a realistic finite element (FE) model to depict the nonlinear dynamics of a vibro-impact capsule moving on the small intestine for active capsule endoscopy. The FE model takes both the nonlinear vibro-impact mechanism and the viscoelastic deformation of the small intestine into account. FE results are compared with the simulation results obtained using non-smooth differential equations and experimental results. It is found that the FE model can provide a more realistic prediction of the system in the complex intestinal environment in terms of capsule’s tilted motion and asymmetric distribution of capsule-intestine contact pressure. In particular, the capsule’s dynamics is very sensitive to the surface condition of the intestine, so a comprehensive bifurcation analysis is needed for fully understanding its dynamics under intestinal peristalsis.=============================================
Date and Time: 11:00 - 12:00, Monday 21 June 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Prof. Morteza Amjadi, Assistant Professor, Department of Mechanical Engineering, Heriot-Watt University, Edinburgh, Scotland, UK
Title: Functional nanomaterial composites for soft sensing and actuation
Abstract: Soft machines have many applications, ranging from multifunctional wearable medical devices for feedback therapy to prosthetics, non-invasive surgical tools, and soft robots for safe human-robot interaction. High-performance flexible sensors and actuators are the key components of soft machines. In this talk, I will cover our latest research activities on the development of functional nanocomposites based wearable sensors for human motion detection and soft robotics. I will demonstrate how bioinspired structures can help to improve the sensing and skin-adhesion performance of wearable sensors. The next part of my talk will focus on the development of programmable soft actuators based on composite materials. Finally, I will address challenges associated with the design of integrated soft machines capable of multimodal sensing and controlled stimulation.
=============================================
Date and Time: 14:00 - 15:00, Monday 14 June 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Prof. Kevin Chen, Assistant Professor, Department of Electrical Engineering and Computer Science, MIT, USA
Title: Agile and robust micro-aerial-robots powered by soft artificial muscles
Abstract: Recent advances in microrobotics have demonstrated remarkable locomotive capabilities such as hovering flights, impulsive jumps, and fast running in insect-scale robots. However, most microrobots that are powered by power-dense rigid actuators have not achieved insect-like collision resilience. Meanwhile, the agility of most soft-actuated microrobots remains limited compared to that of rigid-actuated robots. In this talk, we will present our recent effort in developing a new class of microrobots – ones that are powered by high bandwidth soft actuators and equipped with rigid appendages for effective interactions with environments. Towards improving collision robustness of micro-aerial robots, we develop the first heavier-than-air aerial robots powered by soft artificial muscles that demonstrate open-loop, passively stable ascending flight as well as closed-loop, hovering flight. In addition, our robot can recover from an in-flight collision and perform a somersault within 0.16 seconds. This work demonstrates for the first time that soft aerial robots can achieve agile and robust flight capabilities absent in rigid-powered micro-aerial vehicles, thus showing the potential of a new class of hybrid soft-rigid robots.
=============================================
Date and Time: 13:30 - 14:30, Friday 28 May 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Professor Przemysław Perlikowski, Faculty of Mechanical Engineering, Lodz University of Technology, Poland
Title: Application of a planetary variator in the tuned mass damper with variable inertance
Abstract: In this talk, we will analyze a planetary variator in terms of dynamical modelling and assessing its efficacy in a tuned mass damper with variable inerter (TMDVI). We will use the modified off-the-shelf planetary variator, and create kinematic and dynamic models of the device and experimentally determine its parameter values. Next, we theoretically consider implementing the device as a part of the TMDVI. The variator enables tuning of the natural frequency of the TMDVI to the current frequency of excitation. Hence, it allows crossing the resonance frequency via an optimal path with small oscillations amplitude of the main body. Additionally, we extend the previously proposed control method of the TMDVI to obtain efficient mitigation of vibrations in a wide range of excitation frequencies. The damped system's amplitude does not exceed 0.0084 [m], which is significantly smaller than the oscillation of the undamped system or system with optimized tuned mass damper.
=============================================
Date and Time: 11:00 - 12:00, Friday 14 May 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Dr Zhihua Xie, Senior Lecturer, School of Engineering, Cardiff University, Cardiff, UK
Title: Numerical simulation of turbulent interfacial flows and fluid-structure interaction
Abstract: Interfacial flows over complex geometries with turbulent flow structures are often found in many hydraulic and coastal engineering applications. The objective of this study is to investigate the fluid dynamics of three-dimensional (3D) free surface flow problems, such as dam-break flow over structures, turbulent open-channel flow over rough beds, and wave-structure interaction. In this talk, a Cartesian cut-cell based multiphase flow code for solving 3D Navier-Stokes equations with interface capturing and large-eddy simulation approach is presented. Some numerical examples are shown to provide some insight into the flow physics and to demonstrate the capability of the numerical tool developed.
=============================================
Date and Time: 13:30 - 14:30, Friday 30 April 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Dr Feng Zhou, University of Electronic Science and Technology of China, Chengdu, China
Title: Flow field analysis of the mechanical aortic bi-leaflet heart valves by using finite element method
Abstract: Under physiological conditions, the opening and closing of the leaflets of an implanted artificial heart valve (AHV) affect the blood components, and therefore, may cause various complications to the patients, such as hemolysis or platelet activation. In this talk, I will analyse the computational fluid model of AHV, which presents the regional distribution of flow shear stress, and evaluate the AHV performance by monitoring the variation of flow velocity and pressure when the blood passes the leaflets in the aortic valve. The obtained results suggest the design of a new mechanical artificial heart valve, including the increases of the maximum opening angle and internal orifice diameter, which can improve the fluid structure interaction and decrease the possibility of damage to blood components.
=============================================
Date and Time: 15:00 - 16:00, Friday 23 April 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Miss Jiajia Zhang, PhD candidate, College of Engineering, Mathematics and Physical Sciences, University of Exeter
Title: Development of a vibro-impact self-propelled capsule in millimetre scale
Abstract: This talk will present the experimental study of a self-propelled capsule endoscope prototype (26 mm in length and 11 mm in diameter) driven by an external electromagnetic field. Mathematical models for both the external electromagnetic coils and the capsule prototype will be introduced. The strength of the magnetic field applied to the capsule was obtained analytically and verified by numerical simulations and experiments. The vibro-impact force exerted on the capsule will be compared with the analytical model and the experiment. By comparing capsule's trajectories under different control parameters, the advantage of using the vibro-impact self-propulsion technique can be revealed. Based on the experimental results, the optimised speed of the prototype can achieve up to 3.85 mm/s. Further ex vivo tests will also be presented to demonstrate the feasibility of the proposed technique for small-bowel endoscopy.
=============================================
Date and Time: 11:00 - 12:00, Friday 16 April 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Dr Marcin Kapitaniak, School of Engineering, University of Aberdeen, UK
Title: Onset to Helical Buckling: FE modelling
Abstract: We develop a new Finite Element to accurately model twisting of rods and capture the bifurcation scenarios leading to helical buckling and various further post-buckling states. Since standard nonlinear beam elements do not account for nonlinearities in torsional modes, as well as for coupling between axial, lateral and torsional modes, we derive a new beam element, which allows us to describe complex helical buckling bifurcation scenarios of a rod subjected to a twisting load. The formulated beam element is systematically tested to assess its predictive capabilities in determining critical torsional buckling loads and its sensitivity to number of elements used. Once the model is validated against commercial FE software (Abaqus), we focus our attention on computing bifurcation scenarios to observe various complex helical configurations and transitions between them. The analysis reveals co-existence between helices with multiple loops for certain values of twisting load. Additionally, we trace the transition onsets between stable helical configurations. The developed FE can be applied to study complex buckling mechanics of engineering and biological structures.
=============================================
Date and Time: 15:00 - 16:00, Friday 9 April 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Professor Benjamin S. Terry, Department of Mechanical and Materials Engineering, University of Nebraska Lincoln, Lincoln, US
Title: Oral delivery of biologics via swallowable mechanical capsules
Abstract: The preferred route of drug administration is oral, but large-molecule biological drugs (biologics), like vaccines and insulin, are delivered parenterally due to their intrinsic instability and low permeability through the physical, chemical, and immunological barriers of the gastrointestinal tract. Innovative swallowable technologies such as drug-loaded dissolvable microneedles, mucoadhesive patches, and various microdevices present unique biologic-carrying capabilities for oral delivery. Swallowable mechanical capsules have been used to diagnose and treat various gastrointestinal pathologies such as Crohn's disease, celiac disease, and small bowel tumors, and research to expand existing technology for drug delivery is still emerging. Our central objective is to orally deliver biologics, and we are accomplishing this via an ingestible mechanical capsule. Specifically, we are developing a capsule to deliver Adalimumab (an anti-inflammatory drug for the treatment of ulcerative colitis) into the submucosal layer of the small intestine. The capsule is designed to passively travel to the small intestine via digestive peristalsis after swallowing. Upon reaching the small intestine, the capsule attaches the drug-carrying payload onto the mucosa via a tissue attachment mechanism (TAM). The TAM is then separated from the capsule and remains adhered to the mucosa while the mechanical capsule exits the body in the typical manner. The primary subsystems of the device were individually validated on human-sized porcine models, and the fully integrated capsule was tested in vitro. The novel platform established in this work could be used for the oral delivery of a variety of biologics that are currently only delivered parenterally.
=============================================
Date and Time: 13:30 - 14:30, Wednesday 31 March 2021
Venue: Zoom (Join Zoom Meeting)
Speaker: Miss Shuning Deng, CSC visiting PhD student, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China
Title: Dynamic analysis of a type of centrifugal governor system with time delay
Abstract: The centrifugal governor devices are commonly used in many rotating machines to prevent them from damages caused by a sudden change of the external load. Extensive works have been done on the modeling and dynamic analysis of the centrifugal governor systems, while much less effort has been made in investigating the time-delay effect. As a matter of fact, the inherent time-delay can widely exist in the centrifugal governor systems, due to many factors including the spring deformation, gear transmission, chemical combustion, and the steam transportation etc. In this talk, the local and global dynamics of the system with and without time delay will be studied in the two-parameter planes, including the stability analysis of equilibrium, the co-dimension one to co-dimension three bifurcations analyses of equilibrium, and the two-parameter dynamics identification. By comparing the dynamical response of the system with and without time delay, it was found that the time delay can have a great impact on the governor dynamics and the necessity of such system with time delay incorporated in the model was verified.
=============================================
Date and Time: 13:30 - 14:15 am, Wednesday 6 November 2019
Venue: Peter Chalk 2.5
Speaker: Mr Yiwei Han, School of Mechatronic Engineering, Southwest Petroleum University, Chengdu, China
Title: Nonlinear dynamic modeling of drill string in horizontal well - a geometrically exact approach
Abstract: A new nonlinear dynamic model of drill string in horizontal well is established based on geometrically exact beam theory and quadrature element method. The model proposed in this work takes into account the geometric nonlinearity of the drill string and the nonlinear contact between the drill string and the borehole. Benefiting from the accuracy of the geometric description of the geometrically exact beam, the model uses a geometrically exact method to describe the contact between the drill string and the borehole. Comparison with experimental results shows that the geometrically exact model can accurately describe the nonlinear characteristics of the drill string. Finally, the characteristics of the movement of drill string under different drilling pressure and rotation speed will be analyzed. Drilling pressure and rotational speed have an effect on the buckling of the drill string. Before buckling, the drill string moves periodically at the bottom of the wellbore. After buckling, the movement of the drill string becomes disordered. The model presented in this work provides a new method for dynamic analysis of drill string.
=============================================
Date and Time: 13:30 - 14:15 am, Friday 30 August 2019
Venue: Harrison 170
Speaker: Dr Moi Hoon Yap, Manchester Metropolitan University, Manchester, UK
Title: Translating Computer Vision Research to Real-World Applications
Abstract: The Human-Centred Computing Group undertakes research in computer vision, games, HCI and AI across the themes of healthcare, medical imaging and sport. In facial analysis, we create new algorithms for face wrinkles detection, micro-expressions detection/recognition, facial inpainting and denoising algorithms. We are working with external partners to deliver our research to real-world applications. This talk covers some of our recent works in facial analysis and medical image analysis. I will also share our journey of diabetic foot ulcer project, beginning from image processing to adoption of deep learning models, and to partnership with Oracle to create cloud-enabled prototype.
=============================================
Date and Time: 11:00 - 12:00 am, Thursday 2 August 2018
Venue: Harrison 102
Speaker: Dr Yao Yan, School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu, China
Title: Unsafe cutting
Abstract: To analyse the multi-stability in the non-linear time-delayed metal cutting process, we employ a classical model of regenerative cutting and introduce the Stribeck effect and process damping to the tool’s rake and flank surfaces. From a practical point of view, the multi-stable regions are considered as unsafe due to its sensitivity to the initial conditions of cutting, which could lead the system to an undesired behaviour. So, it is vital to evaluate cutting safety through estimating its unsafe zones. For this purpose, we have attempted to define the basins of attraction and basin's stability by using this cutting model in order to get insight into the issues of cutting safety. Special attention will be paid to the influences of delayed initial conditions, starting points, and the states at time zero on the long-term dynamics of such a time-delayed cutting system. Finally, by using the analytical perturbation methods, our new model shows that the Stribeck effect affects the estimation of the unsafe zones excessively, so that only a very small part of the estimation is acceptable.
=============================================
Date and Time: 11:00 - 12:00 am, Monday 30 July 2018
Venue: Harrison 102
Speaker: Professor Joseph Páez Chávez, Department of Mathematics, Faculty of Natural Sciences and Mathematics, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador
Title: A model for Dengue transmission dynamics with seasonal effects and impulsive control
Abstract: In this talk we will introduce an SIR epidemiological model describing the vector-to-host and host-to-vector transmission dynamics of Dengue. The proposed model includes vector control in terms of pesticide applications, mathematically described as impulsive perturbations in the system, thereby accounting for reductions of the vector population in very short time intervals. In addition, seasonality is incorporated into the model via a sinusoidal forcing mimicking periodic regimes of the intensity of vector-to-host and host-to-vector infections, as well as vector growth. A detailed numerical analysis of the model is carried out via path-following techniques for non-smooth systems, implemented via the software COCO. The numerical study also considers the optimization of the times at which pesticide is applied.
=================================================
Date and Time: 10:30 - 11:30 am, Monday 18 December 2017
Venue: LSI Seminar Room A
Speaker: Dr Luigi Manfredi, Institute for Medical Science and Technology, School of Medicine, University of Dundee, Dundee, UK
Title: Design and Construction of a Mini Snake-Like Medical Robot
Abstract: This talk presents the design and construction of a novel mini snake-like robotic endoscope developed within the ERC Proof of Concept grant “Compliant Actuation Robotic Platform for Flexible Endoscopy” (CARPE), based on a novel and patented “Active Tether Concept” (ATC). In contrast with a traditional “push colonoscope”, the smart control provides an active locomotion reducing the force exchanged with the colonic wall, and therefore, the pain and discomfort in the procedure. The robotic frame is designed by finite element analysis to achieve a weight of only 0.7 grams for each joint, and a high force/torque to weight ration. ATC has an external diameter of 13 mm and a central hollow space of 5 mm, which can be used for essential services, such as suction/irrigation and biopsy channel. The head of the robot can carry a HD camera and the flexible active robotic endoscope will be controlled from an external console.