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Using Nonlinear Normal Modes for Execution of Efficient Cyclic Motions in Soft Robots

TitleUsing Nonlinear Normal Modes for Execution of Efficient Cyclic Motions in Soft Robots
Publication TypeJournal Article
Year of PublicationSubmitted
AuthorsC. Della Santina,, Lakatos, D, Bicchi, A, Albu-Schaeffer, A
JournalIEEE Transactions on Robotics
Type of ArticleRegular paper
Abstract

With the aim of getting closer to the performance of the animal muscleskeletal system, elastic elements are purposefully introduced in the mechanical structure of soft robots. Indeed, previous works have extensively shown that elasticity can endow robots with the ability of performing tasks with increased efficiency, peak performances, and mechanical robustness. However, despite the many achievements, a general theory of efficient motions in soft robots is still lacking. Most of the literature focuses on specific examples, or imposes a prescribed behavior through dynamic cancellations, thus defeating the purpose of introducing elasticity in the first place. This paper aims at making a step towards establishing such a general framework. To this end, we leverage on the theory of oscillations in nonlinear dynamical systems, and we take inspiration from state of the art theories about how the human central nervous system manages the muscleskeletal system. We propose to generate regular and efficient motions in soft robots by stabilizing sub-manifolds of the state space on which the system would naturally evolve. We select these sub-manifolds as the nonlinear continuation of linear eigenspaces, called nonlinear normal modes. In such a way, efficient oscillatory behaviors can be excited. We show the effectiveness of the methods in simulations on an elastic inverted pendulum, and experimentally on a segmented elastic leg.

Hap-Pro: a wearable haptic device for proprioceptive feedback

TitleHap-Pro: a wearable haptic device for proprioceptive feedback
Publication TypeJournal Article
Year of Publication2018
AuthorsRossi, M, Bianchi, M, Battaglia, E, Catalano, MG, Bicchi, A
JournalIEEE Transactions on Biomedical Engineering
Pagination1-1
ISSN0018-9294
Keywordshaptic feedback, haptic interfaces, proprioception, Prosthetic hand, Robot sensing systems, Skin, upper extremity prosthesis, Visualization, Wheels
DOI10.1109/TBME.2018.2836672

WALK-MAN Humanoid Robot: Field Experiments in a Post-earthquake Scenario

TitleWALK-MAN Humanoid Robot: Field Experiments in a Post-earthquake Scenario
Publication TypeJournal Article
Year of Publication2018
AuthorsNegrello, F, Settimi, A, Caporale, D, Lentini, G, Poggiani, M, Kanoulas, D, Muratore, L, Luberto, E, Santaera, G, Ciarleglio, L, Ermini, L, Pallottino, L, Caldwell, DG, Tsagarakis, N, Bicchi, A, Garabini, M, Catalano, MG
JournalIEEE Robotics Automation Magazine
Pagination1-1
ISSN1070-9932
KeywordsBuildings, Earthquakes, Hardware, Legged locomotion, Robot sensing systems, Task analysis
DOI10.1109/MRA.2017.2788801

Aerial Co-Manipulation With Cables: The Role of Internal Force for Equilibria, Stability, and Passivity

TitleAerial Co-Manipulation With Cables: The Role of Internal Force for Equilibria, Stability, and Passivity
Publication TypeJournal Article
Year of Publication2018
AuthorsTognon, M, Gabellieri, C, Pallottino, L, Franchi, A
JournalIEEE Robotics and Automation Letters
Volume3
Pagination2577-2583
Date PublishedJuly
KeywordsAdmittance, Aerial systems: mechanics and control, distributed robot systems, Force, mobile manipulation, multi-robot systems, Robot kinematics, Stability criteria, Transportation
DOI10.1109/LRA.2018.2803811

Towards Dexterous Manipulation with Augmented Adaptive Synergies: the Pisa/IIT SoftHand 2

TitleTowards Dexterous Manipulation with Augmented Adaptive Synergies: the Pisa/IIT SoftHand 2
Publication TypeJournal Article
Year of Publication2018
AuthorsC. Della Santina,, Piazza, C, Grioli, G, Catalano, MG, Bicchi, A
JournalIEEE Transactions on Robotics
VolumeEarly Access
Date Published06/2018
Type of ArticleRegular Paper
ISSNPrint 1552-3098; Onlline 1941-0468
Other NumbersD.O.I. 10.1109/TRO.2018.2830407
Abstract

In the recent years, a clear trend towards simplification emerged in the development of robotic hands. The use of soft robotic approaches has been a useful tool in this prospective, enabling complexity reduction by embodying part of grasping intelligence in the hand mechanical structure. Several hand prototypes designed according to such principles have accomplished good results in terms of grasping simplicity, robustness, and reliability. Among them, the Pisa/IIT SoftHand demonstrated the feasibility of a large variety of grasping tasks, by means of only one actuator and an opportunely designed tendon driven differential mechanism. However, the use of a single degree of actuation prevents the execution of more complex tasks, like fine pre-shaping of fingers and in-hand manipulation. While possible in theory, simply doubling the Pisa/IIT SoftHand actuation system has several disadvantages, e.g. in terms of space and mechanical complexity. To overcome these limitations we propose a novel design framework for tendon driven mechanisms, where the main idea is to turn transmission friction from a disturbance into a design tool. In this way the degrees of actuation can be doubled with little additional complexity.

By leveraging on this idea we design a novel robotic hand, the Pisa/IIT SoftHand 2. We present here its design, modeling, control, and experimental validation. The hand demonstrates that by opportunely combining only two degrees of actuation with hand softness, a large variety of grasping and manipulation tasks can be performed only relying on the intelligence embodied in the mechanism. Examples include rotating objects with different shapes, opening a jar, pouring coffee from a glass.

Efficient Walking Gait Generation via Principal Component Representation of Optimal Trajectories: Application to a Planar Biped Robot With Elastic Joints

TitleEfficient Walking Gait Generation via Principal Component Representation of Optimal Trajectories: Application to a Planar Biped Robot With Elastic Joints
Publication TypeJournal Article
Year of Publication2018
AuthorsGasparri, GM, Manara, S, Caporale, D, Averta, G, Bonilla, M, Marino, H, Catalano, MG, Grioli, G, Bianchi, M, Bicchi, A, Garabini, M
JournalIEEE Robotics and Automation Letters
Volume3
Pagination2299–2306
Abstract

Recently, the method of choice to exploit robot dynamics for efficient walking is numerical optimization (NO). The main drawback in NO is the computational complexity, which strongly affects the time demand of the solution. Several strategies can be used to make the optimization more treatable and to efficiently describe the solution set. In this letter, we present an algorithm to encode effective walking references, generated offline via numerical optimization, extracting a limited number of principal components and using them as a basis of optimal motions. By combining these components, a good approximation of the optimal gaits can be generated at run time. The advantages of the presented approach are discussed, and an extensive experimental validation is carried out on a planar legged robot with elastic joints. The biped thus controlled is able to start and stop walking on a treadmill, and to control its speed dynamically as the treadmill speed changes.

Unvealing the principal modes of human upper limb movements through functional analysis

TitleUnvealing the principal modes of human upper limb movements through functional analysis
Publication TypeJournal Article
Year of Publication2017
AuthorsAverta, G, C. Della Santina,, Battaglia, E, Felici, F, Bianchi, M, Bicchi, A
JournalFrontiers in Robotics and AI
Volume4
Pagination37
Abstract

The rich variety of human upper limb movements requires an extraordinary coordination of different joints according to specific spatio-temporal patterns. However, unvealing these motor schemes is a challenging task. Principal components have been often used for analogous purposes, but such an approach relies on hypothesis of temporal uncorrelation of upper limb poses in time. To overcome these limitations, in this work, we leverage on functional principal component analysis (fPCA). We carried out experiments with 7 subjects performing a set of most significant human actions, selected considering state-of-the-art grasp taxonomies and human kinematic workspace. fPCA results show that human upper limb trajectories can be reconstructed by a linear combination of few principal time-dependent functions, with a first component alone explaining around 60/70% of the observed behaviors. This allows to infer that in daily living activities humans reduce the complexity of movement by modulating their motions through a reduced set of few principal patterns. Finally, we discuss how this approach could be profitably applied in robotics and bioengineering, opening fascinating perspectives to advance the state of the art of artificial systems, as it was the case of hand synergies.

Systemic and vascular inflammation in an in-vitro model of central obesity

TitleSystemic and vascular inflammation in an in-vitro model of central obesity
Publication TypeJournal Article
Year of Publication2018
AuthorsAhluwalia, A, Misto, A, Vozzi, G, Magliaro, C, Mattei, G, MC, M, AVOGARO, A, Iori, E
JournalPLoS ONE
Date Published02/2018
KeywordsBioengineering
Abstract

Metabolic disorders due to over-nutrition are a major global health problem, often associated with obesity and related morbidities. Obesity is peculiar to humans, as it is associated with lifestyle and diet, and so difficult to reproduce in animal models. Here we describe a model of human central adiposity based on a 3-tissue system consisting of a series of interconnected fluidic modules. Given the causal link between obesity and systemic inflammation, we focused primarily on pro-inflammatory markers, examining the similarities and differences between the 3-tissue model and evidence from human studies in the literature. When challenged with high levels of adiposity, the in-vitro system manifests cardiovascular stress through expression of E-selectin and von Willebrand factor as well as systemic inflammation (expressing IL-6 and MCP-1) as observed in humans. Interestingly, most of the responses are dependent on the synergic interaction between adiposity and the presence of multiple tissue types. The set-up has the potential to reduce animal experiments in obesity research and may help unravel specific cellular mechanisms which underlie tissue response to nutritional overload.

URLhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.0192824
DOI10.1371/journal.pone.0192824.s001
Refereed DesignationRefereed

Decentralized Trajectory Tracking Control for Soft Robots Interacting with the Environment

TitleDecentralized Trajectory Tracking Control for Soft Robots Interacting with the Environment
Publication TypeJournal Article
Year of Publication2018
AuthorsAngelini, F, C. Della Santina,, Garabini, M, Bianchi, M, Gasparri, GM, Grioli, G, Catalano, MG, Bicchi, A
JournalIEEE Transactions on Robotics (T-RO).
VolumeEarly Access
Date Published06/2018
KeywordsRobotics
Abstract

Despite the classic nature of the problem, trajectory

tracking for soft robots, i.e. robots with compliant elements

deliberately introduced in their design, still presents several

challenges. One of these is to design controllers which can

obtain sufficiently high performance while preserving the physical

characteristics intrinsic to soft robots. Indeed, classic control

schemes using high gain feedback actions fundamentally alter the

natural compliance of soft robots effectively stiffening them, thus

de facto defeating their main design purpose. As an alternative

approach, we consider here to use a low-gain feedback, while

exploiting feedforward components. In order to cope with the

complexity and uncertainty of the dynamics, we adopt a decentralized,

iteratively learned feedforward action, combined with

a locally optimal feedback control. The relative authority of the

feedback and feedforward control actions adapts with the degree

of uncertainty of the learned component. The effectiveness of the

method is experimentally verified on several robotic structures

and working conditions, including unexpected interactions with

the environment, where preservation of softness is critical for

safety and robustness.

Refereed DesignationRefereed

Grasp Performance of a Soft Synergy-Based Prosthetic Hand: A Pilot Study

TitleGrasp Performance of a Soft Synergy-Based Prosthetic Hand: A Pilot Study
Publication TypeJournal Article
Year of Publication2017
AuthorsGailey, AS, Godfrey, SB, Breighner, R, Andrews, K, Zhao, K, Bicchi, A, Santello, M
Journal IEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume25
Issue12
Pagination2407 - 2417
Date Published12/2017
ISSN1534-4320
Accession Number17397794
KeywordsHaptics, Robotics
Abstract

Current prosthetic hands are frequently rejected in part due to limited functionality and versatility. We assessed the feasibility of a novel prosthetic hand, the SoftHand Pro (SHP), whose design combines soft robotics and hand postural synergies. Able-bodied subjects (n = 23) tracked cursor motion by opening and closing the SHP and performed a grasp-lift-hold-release (GLHR) task with a sensorized cylindrical object of variable weight. The SHP control was driven by electromyographic (EMG) signals from two antagonistic muscles. Although the time to perform the GLHR task was longer for the SHP than native hand for the first few trials (10.2 ± 1.4 s and 2.13 ± 0.09 s, respectively), performance was much faster on subsequent trials (~5 s). The SHP steady-state grip force was significantly modulated as a function of object weight (p <; 0.001). For the native hand, however, peak and steady-state grip forces were modulated to a greater extent (+68% and +91%, respectively). These changes were mediated by the modulation of EMG amplitude and co-contraction. These data suggest that the SHP has a promise for prosthetic applications and point-to-design modifications that could improve the SHP.

URLhttp://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8094246
DOI10.1109/TNSRE.2017.2737539
Custom 1

Research reported in this publication was supported by the Grainger Foundation, the Eunice Kennedy Shriver National Institute Of Child Health and Human Development of the National Institutes of Health (NIH) under Award Number R21HD081938, and the European Commission within Horizon 2020 2015.ICT.24a Robot- ics RIA, with Grant no. 688857 “SOFTPRO -Synergy-based Open-source Foundations and Technologies for Prosthetics and RehabilitatiOn.” 

Refereed DesignationRefereed

The SoftHand Pro-H: A Hybrid Body-Controlled, Electrically Powered Hand Prosthesis for Daily Living and Working

TitleThe SoftHand Pro-H: A Hybrid Body-Controlled, Electrically Powered Hand Prosthesis for Daily Living and Working
Publication TypeJournal Article
Year of Publication2017
AuthorsPiazza, C, Catalano, MG, Godfrey, SB, Rossi, M, Grioli, G, Bianchi, M, Zhao, K, Bicchi, A
JournalIEEE Robotics and Automation Magazine
Date Published11/2017
ISSN1070-9932
KeywordsHaptics, Robotics
Notes

This work was supported by the European Commission project (Horizon 2020 research program) SOFTPRO 688857, the European Research Council under the Advanced Grant SoftHands “A Theory of Soft Synergies for a New Generation of Artificial Hands,” ERC-291166, and the Proof of Concept Project SoftHand Pro-H, ERC-2016-PoC 727536. 

URLhttp://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8110634
DOI10.1109/MRA.2017.2751662
Refereed DesignationRefereed

Combining electroencephalographic activity and instantaneous heart rate for assessing brain–heart dynamics during visual emotional elicitation in healthy subjects

TitleCombining electroencephalographic activity and instantaneous heart rate for assessing brain–heart dynamics during visual emotional elicitation in healthy subjects
Publication TypeJournal Article
Year of Publication2016
AuthorsValenza, G, Greco, A, Gentili, C, Lanatà, A, Sebastiani, L, Menicucci, D, Gemignani, A, Scilingo, EP
JournalPhil. Trans. R. Soc. A
Volume374
Pagination20150176
KeywordsBioengineering
Refereed DesignationRefereed

Pages