An Electricity-Free Snake-Like Propulsion Mechanism Driven and Controlled by Fluids

Abstract-Unlike ordinary snake-like robots, a propulsion mechanism that does not rely on electricity for control and actuation is proposed in this paper. Analysis of a snake's propulsion based on a continuum model unveils that the lateral undulation can be achieved by bending the body at torque proportional to the curvature derivative of the body curve, as observed in muscular activities of biological snakes. Thanks to the simplicity of this principle, a pure mechanical structure comprising a fluid servomechanism can be realized. The proposed propulsion mechanism also consists of gears that propagate the joint angle information to the posterior joint to mechanically simulate curvature derivative

A fully decentralized control of an amoeboid robot by exploiting the law of conservation of protoplasmic mass

2008 IEEE International Conference on Robotics and Automation, Pasadena, CA, USA, May 19-23, 200

On the Embodiment That Enables Passive Dynamic Bipedal Running

2008 IEEE International Conference on Robotics and Automation, Pasadena, CA, USA, May 19-23, 200

An efficient decentralized learning by exploiting biarticular muscles - A case study with a 2D serpentine robot -

2008 IEEE International Conference on Robotics and Automation, Pasadena, CA, USA, May 19-23, 200

Behavioural robustness and the distributed mechanisms hypothesis

A current challenge in neuroscience and systems biology is to better understand properties that allow organisms to exhibit and sustain appropriate behaviours despite the effects of perturbations (behavioural robustness). There are still significant theoretical difficulties in this endeavour, mainly due to the context-dependent nature of the problem. Biological robustness, in general, is considered in the literature as a property that emerges from the internal structure of organisms, rather than being a dynamical phenomenon involving agent-internal controls, the organism body, and the environment. Our hypothesis is that the capacity for behavioural robustness is rooted in dynamical processes that are distributed between agent ‘brain’, body, and environment, rather than warranted exclusively by organisms’ internal mechanisms. Distribution is operationally defined here based on perturbation analyses. Evolutionary Robotics (ER) techniques are used here to construct four computational models to study behavioural robustness from a systemic perspective. Dynamical systems theory provides the conceptual framework for these investigations. The first model evolves situated agents in a goalseeking scenario in the presence of neural noise perturbations. Results suggest that evolution implicitly selects neural systems that are noise-resistant during coupling behaviour by concentrating search in regions of the fitness landscape that retain functionality for goal approaching. The second model evolves situated, dynamically limited agents exhibiting minimalcognitive behaviour (categorization task). Results indicate a small but significant tendency toward better performance under most types of perturbations by agents showing further cognitivebehavioural dependency on their environments. The third model evolves experience-dependent robust behaviour in embodied, one-legged walking agents. Evidence suggests that robustness is rooted in both internal and external dynamics, but robust motion emerges always from the systemin-coupling. The fourth model implements a historically dependent, mobile-object tracking task under sensorimotor perturbations. Results indicate two different modes of distribution, one in which inner controls necessarily depend on a set of specific environmental factors to exhibit behaviour, then these controls will be more vulnerable to perturbations on that set, and another for which these factors are equally sufficient for behaviours. Vulnerability to perturbations depends on the particular distribution. In contrast to most existing approaches to the study of robustness, this thesis argues that behavioural robustness is better understood in the context of agent-environment dynamical couplings, not in terms of internal mechanisms. Such couplings, however, are not always the full determinants of robustness. Challenges and limitations of our approach are also identified for future studies

A Systematic Approach to the Design of Embodiment with Application to Bio-Inspired Compliant Legged Robots

Bio-inspired legged robots with compliant actuation can potentially achieve motion properties in real world scenarios which are superior to conventionally actuated robots. In this thesis, a methodology is presented to systematically design and tailor passive and active control elements for elastically actuated robots. It is based on a formal specification of requirements derived from the main design principles for embodied agents as proposed by Pfeifer et al. which are transfered to dynamic model based multi objective optimization problems. The proposed approach is demonstrated and applied for the design of a biomechanically inspired, musculoskeletal bipedal robot to achieve walking and human-like jogging