Enabling Technologies for Actuated Continuum Surfaces Undergoing Large Deformations

Lead Research Organisation: University of Nottingham
Department Name: Faculty of Engineering

Abstract

Controllable Large Displacement Continuum Surfaces, LCDS, hold the potential for application across a diverse range of applications including the highly dexterous manipulation of parts in manufacturing environments, soft/flexible exoskeleton systems in healthcare, and jointless surface control in the aerospace, automotive, energy and food processing industries. Another application with immediate benefit across multiple industries would be to replace conventional mould surfaces used in the development of bespoke carbon fibre components with a single, reconfigurable surface capable of forming on-demand to desired mould profiles from digital files. Currently low volume production line moulds are produced through expensive (hand carved, milling, turning, and more recently 3D printing) methods that can account for upwards of 20% of a component's manufacturing cost. The use of LCDS systems to form on-demand mould shapes for low volume parts would result in massive savings to the production of such components.

The problem is that to date LDCS operate in 'open loop' with little or no sensor feedback capability to maintain desired curvature under changing conditions, or consideration as to how external forces might best be accounted for. Additionally, placement of actuation elements on the surface to achieve complex profiles is largely accomplished through user intuition and experience, limiting efficiency at the design stage. This results in 'trial and error' methods to LDCS design and control that increase production costs and reduce surface performance under operation. To move beyond 'trial by error' design and control of LDCS undergoing large elastic deformations, accurate, yet computationally efficient, methodologies to model and simulate in both the kinematic and dynamic domains are required.

This project will advance the use of LDCS into the next realm by providing the tools necessary to enable robust procedures for their design and control based not on 'trial and error', but physical model information within an accurate and efficient structure. This will not only make direct, meaningful contributions to the use of LDCS in carbon fibre production. But open further applications of LDCS to areas such as the highly dexterous manipulation of parts in manufacturing environments, soft/flexible exoskeleton systems in healthcare, and deformable surface control in the aerospace, automotive, energy and food processing industries.

Planned Impact

In the short-term, the main beneficiaries of the research will be academic. This research will provide valuable insight into the design, simulation and control of actuated Large Displacement Continuum Surfaces, LDCS. For the first time resulting models will provide a direct link between physical systems and kinematic and dynamic simulations to enable the formation of inverse kinematic and forward dynamic techniques to determine relevant actuator displacements from desired surface profiles, and/or to predict actuator actions based on force interactions respectively. When combined with model based control algorithms and impedance control techniques this will enable whole body compliant, position and force, control of surface interfaces across a number of application industries.

In the long-term the results acquired from this research will assist in the development of improved analytical and numerical design tools for LCDS, giving the UK a direct competitive advantage across a number of industries including the mouldless production of bespoke carbon fibre parts; highly dexterous manipulation of a variety of parts (geometry and material, including deformable objects) in manufacturing environments through compliant whole end-effector systems that are more adaptable and robust to part changes; soft/flexible exoskeleton systems in healthcare to improve patient mobility and comfort by reducing the need for rigid body based systems that are bulky and cumbersome to use; mobile platforms that explore difficult to reach areas using "squishy" robots that manipulate their entire form to provide motion; and the development of whole surface deformation control for the aerospace, automotive, energy and food processing industries that can optimize surface area to improve and/or direct flow over the structure as desired. Links within the Institute for Advanced Manufacturing, IfAM, will be utilized to engage with industrial entities through connections to the Manufacturing Technology Centre (MTC) in Coventry, (where the University of Nottingham is a partner), Manufacturing Technology Engineering Doctorate Centre (MTEDC), and National Composites Centre (NCC) in Bristol to accelerate impact.

The expertise gained by the research team will be extremely valuable and lead to further developments across multiple domains. The skills and experience acquired by the early career researchers involved in this project will assist in their long-term development. The integration of international collaborators with parallel research interests ensures maximum impact from the start, and will help develop an appreciation of the complexity of the problem.

Additionally, robotics is a growing area of interest to the public and media, evidenced by the PI's recent involvement in the BBC2 programme "Biomimetics: Designed by Nature". The PI will leverage this interest by engaging the University of Nottingham press office to release news about the project via the University web pages and work with contacts at the BBC on potential follow up activities. The PI will also use his involvement in University outreach activities such as community open days and UCAS visit days to present his research to a wider public audience and inspire the next generation of engineers.
 
Description Currently, soft actuated flexible surfaces are experiencing high interest and demand for robotic applications in various areas such as healthcare, automotive, aerospace, and manufacturing. However, their design and control thus far have previously been based on 'trial and error' methods requiring multiple trials and/or high levels of user specialization. Robust methods to realize actuated flexible surfaces with the ability to deform into large curvatures therefore require a reliable, validated model that takes into account many physical and mechanical properties including elasticity, material characteristics, gravity, external forces and thickness shear effects. The derivation of such a model would then enable the further development of predictive based control methods for flexible robotic surfaces. This work has developed, and validated a lumped-mass model for flexible surfaces undergoing large deformation due to actuation by continuum robotic arms. The resulting model includes dynamic properties for both the surface and actuation elements to predict deformation in multiple curvature directions and actuation configurations, as well as account for external loading. The model is validated against an experimental system, and measured displacements between the experimental and modelling results showed considerable agreement between the developed model and manufactured surface with an average error less than 1% of the length of the surface's side during movement and at final deformed shapes.

Results have been published in multiple conference and journal proceedings with a further 3 publications in SNIP top 10% manufacturing and robotics journals under review. Invited presentations at multiple US and China institutions have been completed along with site visits to Clemson University (USA), Vanderbilt University (USA), Tsinghua University (China) and Tianjin University (China). The researcher on the project has used his experience here and translated it to a new research and teaching position at a UK university.
Exploitation Route In the short time frame of this project this work has accelerated future academic partnerships though national and international collaborator site visits, invited presentations at conferences and publication of multiple journal and conference proceedings with more in progress. The modelling has reached a stage of maturity that it can be linked to specific design practices for such surfaces and future collaborative work is being discussed considering integration of developed modelling techniques with two different methods of surface design/construction. It is anticipated in the next year that a further 3 Journal publications will result in Manufacturing and Robotics Journals.
Sectors Healthcare,Manufacturing, including Industrial Biotechology

 
Description Royal Society International Exchange Scheme - 2015 China (NSFC)
Amount £11,900 (GBP)
Funding ID IE151006 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 04/2016 
End 03/2018
 
Description Chair of Session 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Chair of invited session at the INternational Symposium on Soft Robotics.

- Hossein Habibi, Rongjie Kang, David Branson III, Actuation of large deformation continuum surfaces (LDCS) in continuum robotics, International Symposium on Soft Robotics, August 1-3, 2017, Xi'an Jiaotong University, Xi'an, China.
Year(s) Of Engagement Activity 2017
 
Description Invited Speaker 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited speaker providing information on the research accomplished to this point and with conversations on future collaboration potential.
- Hossein Habibi, David Branson III, "Actuation of large-deformation robotic-based continuum surfaces: modeling and control approach", 6 April 2018, Laboratorio de Ingeniería Mecánica, University of La Coruña, Ferrol, Spain.
Year(s) Of Engagement Activity 2018
 
Description Invited speaker and seminar chairman 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Invited Speaker and Seminar Chairman at International Symposium on Soft Robotics, August 1-3, 2017, Xi'an Jiaotong University, Xi'an, China.
Year(s) Of Engagement Activity 2017
 
Description Visit to Chinese Universities 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Visit was made to collaborating universities in China, namely Tianjin University and Tsinghua University, where discussions were held with partners on the work to date and potential future collaboration. Most meetings were face to face or small group in nature. Talks also included interaction with graduate and undergraduate students to discuss activities that they were engaged in. It is hoped that visits will be made by some of the people I met to the UK in the near future.
Year(s) Of Engagement Activity 2018
 
Description Visit to Chinese Universities 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Visit was made to collaborating universities in China, namely Tianjin University and Tsinghua University, where discussions were held with partners on the work to date and potential future collaboration. Most meetings were face to face or small group in nature. Talks also included interaction with graduate and undergraduate students to discuss activities that they were engaged in. .
Year(s) Of Engagement Activity 2017
 
Description Visit to Collaborating Universities in the US (Clemson University and Vanderbilt University) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Visit was made to collaborating universities in the US, namely Clemson University and Vanderbilt University, where discussions were held with partners on the work to date and to organize how work will proceed in future. Further talks were held with other academic/postgraduate/undergraduate members of related departments in Mechanical, Bio-engineering and Electrical Engineering to discuss possible future engagement activities and research opportunities. Most meetings were face to face or small group in nature. Talks also included interaction with graduate and undergraduate students to discuss activities that they were engaged in. It is hoped that visits will be made by some of the people I met to the UK although firm plans were not made.
Year(s) Of Engagement Activity 2017