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RoBuSt: Robotic Lower Back Support

English title RoBuSt: Robotic Lower Back Support
Applicant Paik Jamie
Number 163292
Funding scheme Project funding
Research institution Laboratoire de robotique reconfigurable EPFL - STI - IGM - RRL
Institution of higher education EPF Lausanne - EPFL
Main discipline Mechanical Engineering
Start/End 01.01.2016 - 31.12.2018
Approved amount 218'918.00
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Keywords (4)

Soft robotics; Adjustable stiffness; Wearable robotics; under-actuated mechanism

Lay Summary (Italian)

Lead
Lower back pain (LBP) affects 80% of the population but we have shown little improvement in pain management in the past two decades despite technological and robotic advances. This common condition affects the general and sporting populations, as well as the young and elder where poor posture and/or high physical load render the spine vulnerable to injury. Useful strategies for giving relief from LBP have not been investigated yet; there are no commercially available devices that can aid people in daily activities by stabilizing the spine and providing proper assistance. This project intends to propose a technology for addressing this challenge.
Lay summary

Il progetto è stato definito con l’obiettivo di utilizzare le innovazioni tecnologiche della robotica “soft” in un dispositivo che funga da interfaccia attiva nell’assistenza di pazienti con dolore lombare.

I dispositivi che verranno sviluppati potranno assistere l’utente lungo tutto il periodo di guarigione:  dell’incidente sino alla fine della riabilitazione.

L’obiettivo del progetto è la progettazione di un dispositivo assistenziale che supporti l’utente nelle azioni quotidiane stabilizzando il settore lombare della colonna vertebrale. 

 

Per raggiungere questo obbiettivo, proponiamo lo sviluppo parallelo di tre dispositivi robotici da usare in sinergia:

 

(A)       Un carapace “soft” composto da meccanismi compilanti. I suoi giunti avranno ampia libertà di movimento, differenti posture potranno essere bloccate e sbloccate a piacere fornendo il supporto lombare necessario.

 

(B)       Un carapace attivo che abbia capacità di movimento distribuite per fornire rigidezza variabile alla struttura

 

(C)       Un carapace per riabilitazione dove attuazione e misurazioni distribuite verranno utilizzate per fornire supporto quando necessario.

 

Il progetto produrrà innovazione nei campi di progettazione e fabbricazione meccanica.

Il progetto permetterà di capire come progettare e fabbricare dispositivi indossabili che interfacciati con il corpo umano possano scambiare un ampia gamma di forze, tali da supportare il peso del corpo o correggerne la postura.

Questo progetto è molto stimolante in quanto si propone di spingere al limite le capacità dei sistemi di attuazione “soft” in uno scenario dove i robot tradizionali sono difficilmente impiegabili.

 

Direct link to Lay Summary Last update: 01.03.2016

Responsible applicant and co-applicants

Employees

Publications

Publication
A Compact Modular Soft Surface With Reconfigurable Shape and Stiffness
Robertson Matthew A., Murakami Masato, Felt Wyatt, Paik Jamie (2018), A Compact Modular Soft Surface With Reconfigurable Shape and Stiffness, in IEEE/ASME Transactions on Mechatronics, 24(1), 16-24.
Low-inertia vacuum-powered soft pneumatic actuator coil characterization and design methodology
Robertson Matthew A., Paik Jamie (2018), Low-inertia vacuum-powered soft pneumatic actuator coil characterization and design methodology, in 2018 IEEE International Conference on Soft Robotics (RoboSoft), LivornoIEEE, Livorno, Italy.
Modeling vacuum bellows soft pneumatic actuators with optimal mechanical performance
Felt Wyatt, Robertson Matthew A., Paik Jamie (2018), Modeling vacuum bellows soft pneumatic actuators with optimal mechanical performance, in 2018 IEEE International Conference on Soft Robotics (RoboSoft), LivornoIEEE, Livorno, Italy.
Design and Computational Modeling of a Modular, Compliant Robotic Assembly for Human Lumbar Unit and Spinal Cord Assistance
Agarwal Gunjan, Robertson Matthew A., Sonar Harshal, Paik Jamie (2017), Design and Computational Modeling of a Modular, Compliant Robotic Assembly for Human Lumbar Unit and Spinal Cord Assistance, in Scientific Reports, 7(1), 14391-14391.
Practical control methods for vacuum driven soft actuator modules
Robertson Matthew A., Paik Jamie (2017), Practical control methods for vacuum driven soft actuator modules, in 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Vancouver, BCIEEE, Vancouver.
New soft robots really suck: Vacuum-powered systems empower diverse capabilities
Robertson Matthew A., Paik Jamie (2017), New soft robots really suck: Vacuum-powered systems empower diverse capabilities, in Science Robotics, 2(9), eaan6357-eaan6357.
JammJoint: A Variable Stiffness Device Based on Granular Jamming for Wearable Joint Support
Hauser Simon, Robertson Matthew, Ijspeert Auke, Paik Jamie (2017), JammJoint: A Variable Stiffness Device Based on Granular Jamming for Wearable Joint Support, in IEEE Robotics and Automation Letters, 2(2), 849-855.
Soft Pneumatic Actuator Fascicles for High Force and Reliability
Robertson Matthew A., Sadeghi Hamed, Florez Juan Manuel, Paik Jamie (2017), Soft Pneumatic Actuator Fascicles for High Force and Reliability, in Soft Robotics, 4(1), 23-32.

Datasets

A Compact Modular Soft Surface With Reconfigurable Shape and Stiffness

Author Robertson, Matthew A.; Murakami, Masato; Felt, Wyatt; Paik, Jamie
Publication date 29.10.2018
Persistent Identifier (PID) 10.1109/TMECH.2018.2878621
Repository Robertson_TMECH
Abstract
A variety of reconfigurable surface devices, utilizing large numbers of actuated physical pixels to produce discretized three-dimensional contours, have been developed for different purposes in research and industry. The difficulty of integrating many actuators in close configuration has limited the DOF and resolution and performance of existing devices. Utilizing vacuum power and soft material actuators, we have developed a soft reconfigurable surface (SRS) with multimodal control and performance capabilities. The SRS is comprised of a square grid array of linear vacuum-powered soft pneumatic actuators, built into plug-and-play modules which enable the arrangement, consolidation, and control of many DoF. In addition to the practical benefits of system integration, this architecture facilitates the construction of customized assemblies with an overall compact form factor. A series of experiments is performed to illustrate and validate the versatility of the SRS for achieving diverse tasks including force-controlled modulation of interface pressure through integrated sensors, lateral manipulation of a variety of objects, static and dynamic shape and pattern generation for haptic interaction, and variable surface stiffness tuning. This SRS concept is scalable, space efficient, and features diverse functional potential. This will extend the utility and accessibility of tangible robotic interfaces for future applications from industrial to home and personal use.

Soft Pneumatic Actuator Fascicles for High Force and Reliability

Author Robertson, Matthew A.; Sadeghi, Hamed; Florez, Juan Manuel; Paik, Jamie
Publication date 01.03.2017
Persistent Identifier (PID) 10.1089/soro.2016.0029
Repository Robertson_SoRo
Abstract
Soft pneumatic actuators (SPAs) are found in mobile robots, assistive wearable devices, and rehabilitative technologies. While soft actuators have been one of the most crucial elements of technology leading the development of the soft robotics field, they fall short of force output and bandwidth requirements for many tasks. In addition, other general problems remain open, including robustness, controllability, and repeatability. The SPA-pack architecture presented here aims to satisfy these standards of reliability crucial to the field of soft robotics, while also improving the basic performance capabilities of SPAs by borrowing advantages leveraged ubiquitously in biology; namely, the structured parallel arrangement of lower power actuators to form the basis of a larger and more powerful actuator module. An SPA-pack module consisting of a number of smaller SPAs will be studied using an analytical model and physical prototype. Experimental measurements show an SPA pack to generate over 112 N linear force, while the model indicates the benefit of parallel actuator grouping over a geometrically equivalent single SPA scale as an increasing function of the number of individual actuators in the group. For a module of four actuators, a 23% increase in force production over a volumetrically equivalent single SPA is predicted and validated, while further gains appear possible up to 50%. These findings affirm the advantage of utilizing a fascicle structure for high-performance soft robotic applications over existing monolithic SPA designs. An example of high-performance soft robotic platform will be presented to demonstrate the capability of SPA-pack modules in a complete and functional system.

New soft robots really suck: Vacuum-powered systems empower diverse capabilities

Author Robertson, Matthew A.; Paik, Jamie
Publication date 30.08.2017
Persistent Identifier (PID) 10.1126/scirobotics.aan6357
Repository Robertson_ScienceRobotics
Abstract
We introduce a vacuum-powered soft pneumatic actuator (V-SPA) that leverages a single, shared vacuum power supply and enables complex soft robotic systems with multiple degrees of freedom (DoFs) and diverse functions. In addition to actuation, other utilities enabled by vacuum pressure include gripping and stiffening through granular media jamming, as well as direct suction adhesion to smooth surfaces, for manipulation or vertical fixation. We investigate the performance of the new actuator through direct characterization of a 3-DoF, plug-and-play V-SPA Module built from multiple V-SPAs and demonstrate the integration of different vacuum-enabled capabilities with a continuum-style robot platform outfitted with modular peripheral mechanisms. We show that these different vacuum-powered modules can be combined to achieve a variety of tasks-including multimodal locomotion, object manipulation, and stiffness tuning-to illustrate the utility and viability of vacuum as a singular alternative power source for soft pneumatic robots and not just a peripheral feature in itself. Our results highlight the effectiveness of V-SPAs in providing core soft robot capabilities and facilitating the consolidation of previously disparate subsystems for actuation and various specialized tasks, conducive to improving the compact design efficiency of larger, more complex multifunctional soft robotic systems.A foam-based, vacuum-powered actuator enables a multifunctional soft robotic system.A foam-based, vacuum-powered actuator enables a multifunctional soft robotic system.

Low-inertia vacuum-powered soft pneumatic actuator coil characterization and design methodology

Author Robertson, Matthew A.; Paik, Jamie
Publication date 01.04.2018
Persistent Identifier (PID) 10.1109/ROBOSOFT.2018.8405364
Repository Robertson_RobosoftConf2018
Abstract
Recently developed soft pneumatic actuators (SPAs) powered by negative pressure have demonstrated great potential in the future of soft robotics for their high strength, intrinsic safety, low weight, and often simple design. The majority of these limited examples have only provided linear force and motion profiles, however, despite the general prevalence of bending actuators common to positive pressure powered SPAs. The benefits of such bending type SPAs follow from the direct production of moment and angular motion that are highly desirable for diverse robotic applications and activities, which allows more simple design of soft robots with complex motion behavior. Following this motivation, a new vacuum powered bending actuator is developed here as an extension of a previously presented vacuum powered actuator, the V-SPA, which features simple, lightweight material construction and rapid fabrication. Leveraging these attributes, an empirical study of a new Coil V-SPA performance is conducted across a spectrum of eight actuator prototypes. The force, speed, and stiffness of the actuators are characterized, and a generalized design metric, the Geometric Compression Ratio (GCR), is defined to quantify the relationship between physical geometric parameters of Coil V-SPAs. Finally, the results of testing reveal the new low-inertia actuator is capable of high-speed, and high-bandwidth motion, up to 0.97 m/s and 1.59 Hz, respectively.

Practical control methods for vacuum driven soft actuator modules

Author Robertson, Matthew A.; Paik, Jamie
Publication date 01.09.2017
Persistent Identifier (PID) 10.1109/IROS.2017.8202296
Repository Robertson_IROS2017
Abstract
Vacuum-powered Soft Pneumatic Actuator (V-SPA) Modules have been described to afford advantages for rapid development of reconfigurable, multi-DoF soft pneumatic robots powered by vacuum by reducing their logistical complexity, however they also present new challenges in the control of resulting systems. This framework features modules joined together over a simple embedded pneumatic and serial communication network and requires a unique approach to both low-level control implementation and high-level control strategy. We describe the structure and activation characteristics of a V-SPA Module and present practical methods for its control. These methods utilize software generated PWM activation through a unique serial protocol designed for LED networks and a heuristic mapping strategy for simplifying the spherical control of 3-DoF actuator modules.

JammJoint: A Variable Stiffness Device Based on Granular Jamming for Wearable Joint Support

Author Hauser, Simon; Robertson, Matthew; Ijspeert, Auke; Paik, Jamie
Publication date 01.04.2017
Persistent Identifier (PID) 10.1109/LRA.2017.2655109
Repository Hauser_RAL
Abstract
In robotics, controlling the stiffness of the joints that contribute to the robots' degree of freedom dictates the adaptability, versatility, and safety of the whole system. We can achieve variable stiffness or impedance in a robotic system purely by the control or by introducing new material or mechanisms to address cases that require innate safety through system compliancy. This paper presents JammJoint, a compliant and flexible wearable robot, which uses jamming of granular media to vary its stiffness. It consists of a silicone sleeve with hollow sections that are filled with cubic rubber granules and subjected to different levels of vacuum pressure. Unlike contemporary vacuum-based actuators or systems, JammJoint is wearable, portable, and autonomous: It uses a powerful miniature vacuum pump, a small battery, and bluetooth-enabled electronics. Experiments revolving around bending and torsional stiffness show that the system is able to achieve up to a fourfold increase in spring stiffness. Further measurements of individual variable stiffness structures indicate that for other modes of deformation, including simply supported bending or compression for alternative linear applications, higher changes in stiffness over a factor of seven are possible. These aspects make mobile jamming-based stiffness variation as wearable joint assistance promising for future applications such as rehabilitation after injuries and joint support in challenging working conditions.

Design and Computational Modeling of a Modular, Compliant Robotic Assembly for Human Lumbar Unit and Spinal Cord Assistance

Author Agarwal, Gunjan; Robertson, Matthew A.; Sonar, Harshal; Paik, Jamie
Publication date 31.12.2017
Persistent Identifier (PID) 10.1038/s41598-017-14220-3
Repository Agarwal_ScientificReports
Abstract
Wearable soft robotic systems are enabling safer human-robot interaction and are proving to be instrumental for biomedical rehabilitation. In this manuscript, we propose a novel, modular, wearable robotic device for human (lumbar) spine assistance that is developed using vacuum driven, soft pneumatic actuators (V-SPA). The actuators can handle large, repetitive loads efficiently under compression. Computational models to capture the complex non-linear mechanical behavior of individual actuator modules and the integrated assistive device are developed using the finite element method (FEM). The models presented can predict system behavior at large values of mechanical deformations and allow for rapid design iterations. It is shown that a single actuator module can be used to obtain a variety of different motion and force profiles and yield multiple degrees of freedom (DOF) depending on the module loading conditions, resulting in high system versatility and adaptability, and efficient replication of the targeted motion range for the human spinal cord. The efficacy of the finite element model is first validated for a single module using experimental results that include free displacement and blocked-forces. These results are then extended to encompass an extensive investigation of bio-mechanical performance requirements from the module assembly for the human spine-assistive device proposed.

Modeling vacuum bellows soft pneumatic actuators with optimal mechanical performance

Author Felt, Wyatt; Robertson, Matthew A.; Paik, Jamie
Publication date 01.04.2018
Persistent Identifier (PID) 10.1109/ROBOSOFT.2018.8405381
Repository Felt_RobosoftConf2018
Abstract
This paper presents the concept and model of “Vacuum Bellows,” a cylindrical membrane-reinforced contractile vacuum soft pneumatic actuator (V-SPAs). These actuators consist of a tubular membrane connected to a series of interior rigid rings periodically spaced along its length. Our model shows how the rings can be spaced to achieve a desired actuator force profile. For example, the contraction ratio can be maximized by spacing the rings one diameter apart inside the tube. The work output of the actuator can be concentrated in the initial portion of the stroke by increasing the ring spacing. And, usefully, an approximately constant force-to-pressure relationship can be created by spacing the rings a fraction of a diameter apart. Our experimental results highlight the utility of the model and some practical considerations for actuator fabrication and use. The experimental results demonstrate how the ring spacing can be used to achieve high peak forces per unit pressure (three times greater than an equivalent-diameter piston achieved experimentally) or large contractions (achieved contraction to 30 % of the extended length). Our model suggests that this performance can be improved with improved fabrication techniques.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Continuum robot workshop: IEEE/RSJ International Conference on Intelligent Robots and Systems Talk given at a conference The future within reach: hyper-redundant manipulator technology, architecture, and application 01.10.2018 Madrid, Spain Paik Jamie; Robertson Matthew Aaron;
Shape changing interfaces workshop: IEEE/RSJ International Conference on Intelligent Robots and Systems Talk given at a conference Soft reconfigurable structures for interactive robotics systems 01.10.2018 Madrid, Spain Paik Jamie; Robertson Matthew Aaron;
IEEE International Conference on Soft Robotics (RoboSoft) Poster Low-inertia vacuum-powered soft pneumatic actuator coil characterization and design methodology 24.04.2018 Livorno, Italy Robertson Matthew Aaron;
Bioinspired@EPFL Individual talk Soft pneumatic actuators and robots inspired by nature 08.04.2018 Lausanne, Switzerland Robertson Matthew Aaron;
Materials Research Society spring meeting and exhibit Talk given at a conference Soft Pneumatic Actuators for Compliant Interactive Robotic Platforms 05.04.2018 Phoenix, AZ, United States of America Paik Jamie; Robertson Matthew Aaron;
IEEE International Conference on Soft Robotics (Robosoft) Poster Parametric study of Pneumatic Circuit Model for Powering and Controlling Soft Pneumatic Actuators 04.04.2018 Livorno, Italy Paik Jamie;
Can We Build Baymax Part 3: Design and Control for Soft Human-Robot Interaction - Humanoids Conference Talk given at a conference Foam-based Vacuum-powered Soft Pneumatic Actuators (V-SPAs) for safe robots 15.11.2017 Birmingham, Great Britain and Northern Ireland Robertson Matthew Aaron;
IEEE/RSJ International Conference on Intelligent Robots and Systems Talk given at a conference Practical control methods for vacuum-driven soft actuator modules 24.09.2017 Vancouver, BC, Canada Robertson Matthew Aaron;
Dynamic Walking Conference Poster Trunk postural tracking of assistive soft pneumatic actuator belt 04.06.2016 Holly, Michigan, United States of America Robertson Matthew Aaron;


Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
NCCR Industry Day Performances, exhibitions (e.g. for education institutions) 01.11.2018 Lausanne, Switzerland Paik Jamie; Robertson Matthew Aaron;
NCCR Industry Day Performances, exhibitions (e.g. for education institutions) 02.11.2017 Lausanne, Switzerland Robertson Matthew Aaron; Paik Jamie;
NCCR Industry Day Performances, exhibitions (e.g. for education institutions) 02.11.2016 Lausanne, Switzerland Paik Jamie; Robertson Matthew Aaron;


Associated projects

Number Title Start Funding scheme
177027 Laser Micro-Machining System for Meso-Manufacturing 01.03.2018 R'EQUIP

Abstract

PROBLEMLower back pain (LBP) affects 80% of the population but we have shown little improvement in pain management in the past two decades despite technological and robotic advances. This common condition affects the general and sporting populations, as well as the young and elder where poor posture and/or high physical load render the spine vulnerable to injury. The abdominal and lumbar muscles provide the major support to the spine during daily activities and high loads situations. While the lack of lumbar musculature is caused mostly by a sedentary lifestyle and unhealthy posture, personal discipline is often insufficient to improve the condition for most patients.LOWER BACK STABILIZATION AND PROTECTION Currently there is no consensus to the best course of pain management for LBP. Even the efficacy of surgical intervention is questioned in comparison to various physical therapy methods. Although there remain large con-troversies in the type, frequency and level of support and exercises required for LBP, it is agreed that an effective regimen should provide: 1. Dynamic lumbar spine stabilization during activities, 2. Full lumbar spine bracing that prevents free motions and 3. Full pelvic and lumbar motion support. As all three aspects of the treatment require contradicting aspects of the physical activity and interface, one cannot simultaneously execute them all. Currently, most people reserve the dynamic exercises until the condition improves or for private sessions at a clinic with assistance from a physical therapist. We need an interactive wearable device that would support lumbar movements to prevent further LBP incidents and to keep patient active.GOAL This project has been designed to translate the breakthroughs in soft robotics to an active interface to assist patients with LBP from the point of the incident to the rehabilitation stage. The goal is not to design medical equipment, but an assistive device to aid daily activities by stabilizing lumbar spine: a device that is more rigid than an elastic corset but more supportive and versatile. We propose to build effective devices to assist multidirectional lumbar spine movements and provide support-as-needed during daily activities as well as specific exercise patterns during the course of low back rehabilitation.OBJECTIVESTo achieve this goal, we propose the parallel development of synergistic robotic devices: (A) Soft carapace: A compliant mechanism with coupled joint bodice with high degrees-of-freedom (DoF). Its joints will move with a large range of motion where any position could be passively locked and unlocked to pro-vide needed lumbar support. Advancement in compliant mechanism design is needed.(B) Active carapace for lumbar support: A distributed actuation solution that will provide active joint stiffness changes. Novel actuation and transmission systems are needed.(C) Active carapace for rehabilitation: An integrated RoBuSt device with distributed actuation and sensing ma-trix that will produce support-as-needed from the adaptive-stiffness lower back brace. Multi-DoF sensorized sur-face control and actuation need to be investigated.STRATEGYAdaptive lower back support: With our solid foundation in soft and wearable robotics, we propose to develop the lumbar assistive device. We will design an interactive device to assist multi-dimensional lumbar support while providing sufficient stiffness to ensure maintenance of the spine posture. We will benefit from our expertise in areas such as novel robotic designs, soft actuation systems, distributed sensing and actuation methodologies to invent new solutions geared toward RoBuSt.IMPACT AND SIGNIFICANCEWearable robots have strict design limitations in terms of interface compliance, high-DoF actuation, and innately safe mechanisms. RoBuSt will develop novel robot components, advance nominally 2D fabrication processes, and integrate under-actuation mechanisms with soft electronics. Such scientific efforts will provide viable solutions for future wearable robot and soft robotics development. The devices will play a central role in the development of treatment for chronic LBP, for both active and passive treatments.
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