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1.
Bioinspir Biomim ; 19(2)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38286005

RESUMO

This paper presents the design and experimental verification of a parallel elastic robotic leg mechanism that aims to capture the dynamics of the linear mass-spring-damper model. The mechanism utilizes a wrapping cam mechanism to linearize the non-linear force resulting from the elongation of the parallel elastic element. Firstly, we explain the desired dynamics of the mass-spring-damper model, including the impact transitions, and the design of the wrapping cam mechanism. We then introduce a system identification procedure to estimate the parameters of the leg mechanism corresponding to the dynamic model. The estimated parameters are tested with a cross-validation approach to evaluate the mechanism's performance in tracking the desired model. The experimental results show that the passive dynamics of the mechanism resemble the linear model as intended. Thus, the robot provides a basis for using parallel elastic actuation while using model-based controllers that benefit the analytic solutions of the linear model.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Robótica/métodos , Modelos Biológicos , Perna (Membro) , Fenômenos Biomecânicos
2.
Front Robot AI ; 9: 791921, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35572369

RESUMO

Honey bees live in colonies of thousands of individuals, that not only need to collaborate with each other but also to interact intensively with their ecosystem. A small group of robots operating in a honey bee colony and interacting with the queen bee, a central colony element, has the potential to change the collective behavior of the entire colony and thus also improve its interaction with the surrounding ecosystem. Such a system can be used to study and understand many elements of bee behavior within hives that have not been adequately researched. We discuss here the applicability of this technology for ecosystem protection: A novel paradigm of a minimally invasive form of conservation through "Ecosystem Hacking". We discuss the necessary requirements for such technology and show experimental data on the dynamics of the natural queen's court, initial designs of biomimetic robotic surrogates of court bees, and a multi-agent model of the queen bee court system. Our model is intended to serve as an AI-enhanceable coordination software for future robotic court bee surrogates and as a hardware controller for generating nature-like behavior patterns for such a robotic ensemble. It is the first step towards a team of robots working in a bio-compatible way to study honey bees and to increase their pollination performance, thus achieving a stabilizing effect at the ecosystem level.

3.
J R Soc Interface ; 17(169): 20200165, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32811297

RESUMO

We study how the structure of the interaction network affects self-organized collective motion in two minimal models of self-propelled agents: the Vicsek model and the Active-Elastic (AE) model. We perform simulations with topologies that interpolate between a nearest-neighbour network and random networks with different degree distributions to analyse the relationship between the interaction topology and the resilience to noise of the ordered state. For the Vicsek case, we find that a higher fraction of random connections with homogeneous or power-law degree distribution increases the critical noise, and thus the resilience to noise, as expected due to small-world effects. Surprisingly, for the AE model, a higher fraction of random links with power-law degree distribution can decrease this resilience, despite most links being long-range. We explain this effect through a simple mechanical analogy, arguing that the larger presence of agents with few connections contributes localized low-energy modes that are easily excited by noise, thus hindering the collective dynamics. These results demonstrate the strong effects of the interaction topology on self-organization. Our work suggests potential roles of the interaction network structure in biological collective behaviour and could also help improve decentralized swarm robotics control and other distributed consensus systems.


Assuntos
Relações Interpessoais , Movimento (Física)
4.
Turk J Med Sci ; 49(4): 1054-1067, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31293146

RESUMO

Background/aim: This study aims to explore the mirror neuron system (MNS) involvement using mu (8­12 Hz)/beta (15­25 Hz) band suppression in an action observation-execution paradigm. Materials and methods: Electrophysiological (EEG) data from 16 electrodes were recorded while 8 participants observed video clips of a hand squeezing a spring. Specifically, the effect of anticipated execution on observation was studied. For this purpose, a fully actuated finger exoskeleton robot was utilized to synchronize observation and execution and to control the execution condition for the partici-pants. Anticipatory effect was created with a randomized robot accompany session. Results: The results showed that the observational condition (with or without anticipation) interacted with hemisphere at central chan-nels near somatosensory cortex. Additionally, we explored the response of MNS on the kinetics features of visual stimuli (hard or soft spring). Conclusion: he results showed an interaction effect of kinetics features and hemisphere at frontal channels corresponding nearly to the ventral premotor cortex area of the brain. The activation of mirror neurons in this area plays a crucial role in observational learning. Based on our results, we propose that specific type of visual stimuli can be combined with the functional abilities of the MNS in the ac-tion observation based treatment of hand motor dysfunction of stroke patients to have a positive additional impact.


Assuntos
Antecipação Psicológica/fisiologia , Exoesqueleto Energizado , Aprendizagem/fisiologia , Neurônios-Espelho/fisiologia , Estimulação Luminosa , Adulto , Eletroencefalografia , Humanos , Masculino , Reabilitação do Acidente Vascular Cerebral , Gravação de Videoteipe
5.
Exp Brain Res ; 236(2): 497-503, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29230518

RESUMO

This study aimed to explore the relationship between action observation (AO)-related corticomotor excitability changes and phases of observed action and to explore the effects of pure AO and concurrent AO and motor imagery (MI) state on corticomotor excitability using TMS. It was also investigated whether the mirror neuron system activity is muscle-specific. Fourteen healthy volunteers were enrolled in the study. EMG recordings were taken from the right first dorsal interosseous and the abductor digiti minimi muscles. There was a significant main effect of TMS timing (after the beginning of the movement, at the beginning of motor output state, and during black screen) on the mean motor evoked potential (MEP) amplitude. Mean MEP amplitudes for AO combined with MI were significantly higher than pure AO session. There was a significant interaction between session and TMS timing. There was no significant main effect of muscle on MEP amplitude. The results indicate that corticomotor excitability is modulated by different phases of the observed motor movement and this modulation is not muscle-specific. Simultaneous MI and AO enhance corticomotor excitability significantly compared to pure AO.


Assuntos
Potencial Evocado Motor/fisiologia , Retroalimentação Sensorial/fisiologia , Imaginação/fisiologia , Neurônios-Espelho/fisiologia , Córtex Motor/fisiologia , Análise de Variância , Eletromiografia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Estimulação Magnética Transcraniana
6.
PLoS Comput Biol ; 11(8): e1004273, 2015 08.
Artigo em Inglês | MEDLINE | ID: mdl-26247819

RESUMO

Division of labor is ubiquitous in biological systems, as evidenced by various forms of complex task specialization observed in both animal societies and multicellular organisms. Although clearly adaptive, the way in which division of labor first evolved remains enigmatic, as it requires the simultaneous co-occurrence of several complex traits to achieve the required degree of coordination. Recently, evolutionary swarm robotics has emerged as an excellent test bed to study the evolution of coordinated group-level behavior. Here we use this framework for the first time to study the evolutionary origin of behavioral task specialization among groups of identical robots. The scenario we study involves an advanced form of division of labor, common in insect societies and known as "task partitioning", whereby two sets of tasks have to be carried out in sequence by different individuals. Our results show that task partitioning is favored whenever the environment has features that, when exploited, reduce switching costs and increase the net efficiency of the group, and that an optimal mix of task specialists is achieved most readily when the behavioral repertoires aimed at carrying out the different subtasks are available as pre-adapted building blocks. Nevertheless, we also show for the first time that self-organized task specialization could be evolved entirely from scratch, starting only from basic, low-level behavioral primitives, using a nature-inspired evolutionary method known as Grammatical Evolution. Remarkably, division of labor was achieved merely by selecting on overall group performance, and without providing any prior information on how the global object retrieval task was best divided into smaller subtasks. We discuss the potential of our method for engineering adaptively behaving robot swarms and interpret our results in relation to the likely path that nature took to evolve complex sociality and task specialization.


Assuntos
Inteligência Artificial , Evolução Biológica , Modelos Biológicos , Robótica , Comportamento Social , Animais , Formigas/fisiologia , Biologia Computacional , Robótica/instrumentação , Robótica/métodos , Análise e Desempenho de Tarefas , Trabalho
7.
Phys Rev Lett ; 111(26): 268302, 2013 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-24483817

RESUMO

We introduce an elasticity-based mechanism that drives active particles to self-organize by cascading self-propulsion energy towards lower-energy modes. We illustrate it on a simple model of self-propelled agents linked by linear springs that reach a collectively rotating or translating state without requiring aligning interactions. We develop an active elastic sheet theory, complementary to the prevailing active fluid theories, and find analytical stability conditions for the ordered state. Given its ubiquity, this mechanism could play a relevant role in various natural and artificial swarms.


Assuntos
Modelos Teóricos , Animais , Comportamento Animal , Cristalização , Elasticidade , Modelos Biológicos , Modelos Químicos
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