DOCSLIB.ORG

Modeling and Validation of Soft Robotic Snake Locomotion

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Modeling and Validation of Soft Robotic Snake Locomotion Modeling and Validation of Soft Robotic Snake Locomotion Dimuthu D. Arachchige1, Yue Chen2, and Isuru S. Godage1 Abstract— Snakes are a remarkable evolutionary success story. Many snake-inspired robots have been proposed over the years. Soft robotic snakes (SRS) with their continuous and smooth bending capability better mimic their biological counterparts’ unique characteristics. Prior SRSs are limited to planar operation with a limited number of planar gaits. We propose a novel SRS with spatial bending and investigate snake locomotion gaits beyond the capabilities of the state-of-the-art systems. We derive a complete floating-base kinematic model of the robot and use the model to derive jointspace trajectories Fig. 1: (A) The proposed Soft robotic snake (SRS) prototype, for serpentine and inward/outward rolling locomotion gaits. (B) Replicating rolling locomotion, and (C) Replicating serpentine The locomotion gaits for the proposed SRS are experimentally locomotion. validated under varying frequency and amplitude of gait cycles. The results qualitatively and quantitatively validate the SRS ability to leverage spatial bending to achieve locomotion gaits not possible with current SRS. locomotion. RRS, with few rigid links, limits the robot from achieving the smooth bending observed in snakes and, I. INTRODUCTION therefore, can affect locomotion. On the other hand, soft Snakes are highly capable animals with a wide range robotic snakes (SRS), constructed mainly from fluidic muscle of habitats, including hostile deserts, dense tropical forests, actuator-powered bodies, can better leverage smooth bending and uninhabitable marshes. One key feature that makes to imitate snake body movements. However, the latest SRS snakes unique in their ability to navigate in different terrains prototypes are limited to planar bending deformation, limit- using various locomotion gaits is supported by their long, ing the number of gaits they can demonstrate. In addition, high degrees of freedom (DoF) slender bodies. The body’s snakes use differential friction property of their skin to continuous and smooth bending structure enables snakes generate locomotion in planar gaits such as serpentine gait. to overcome numerous environmental challenges such as Noting the absence of such quality in current SRS, it is climbing, swimming despite having no sophisticated ap- extremely challenging to propel robots solely via planar pendages such as limbs. Their high DoF body can generate locomotion gaits. Consequently, SRSs rely on wheels to a range of locomotion gaits such as lateral undulation, circumvent uniform friction and generate locomotion [10], rectilinear movement, sidewinding, concertina movement. [11]. Thus, we posit that it is essential to exploit the out-of- Snake-like robots can harness this traversability in different plane deformation (spatial bending) to replicate locomotion and challenging terrains in applications such as inspection gaits such as rolling and sidewinding. The SRS reported tasks, reconnaissance, search, and rescue operations. Their in [9], [12] generates serpentine locomotion but utilizes small cross-section to length ratio allows them to gain wheeled bases to generate friction anisotropy necessary for access through tight spaces, little narrow openings (i.e., movement. The ‘WPI SRS’ [13] reported 10-fold locomotion sewage lines), and perform assigned operations. Robotics speed increase than the previous version [8]. The SRS arXiv:2010.11476v1 [cs.RO] 22 Oct 2020 have developed various snake robot prototypes [1]–[10] to presented in [14] and [15] is self-contained with integrated meet the aforementioned application challenges. sensing and feedback control. It improves the accuracy of dynamic undulatory locomotion. We propose a novel SRS A. Prior Work with spatial bending capabilities to address these limitations. Prior work on snake robots mainly evolved with modular B. Contribution rigid robots [1], [2], [5]–[7]. Rigid robotic snakes (RRS) use The main contributions of this work are (a) propose jointed rigid links to achieve bending motion and generate a novel SRS with spatial bending capability, (b) derive 1Dimuthu D. Arachchige and Isuru S. Godage are with School of Comput- complete floating base kinematic model, (c) derive jointspace ing, DePaul University, Chicago, IL, 60604. [email protected] trajectories of serpentine, inward rolling, and outward rolling 2Yue Chen is with the Department of Mechanical Engineering, University snake locomotion gaits, (d) experimentally validate the said of Arkansas Fayetteville, AR, 72701. locomotion gaits for a range of pressure-frequency combina- This work supported in part by the National Science Foundation grants IIS- tions on the propose SRS, (e) demonstrate the need for spatial 1718755 and and IIS-2008797 and UARK Chancellor’s Fund for Innovation and Collaboration. bending to overcome the limitations of friction anisotropy This paper has been submitted to IEEE International Conference on Robotics present in practical SRS. The experimental results show that and Automation 2021. SRS can successfully track the spatial shape trajectories for Fig. 3: Trajectory sampling at different time instances within a gait cycle for (a) serpentine gait and (b) outward rolling gait. B. Kinematic Model Consider the schematic of any ith module (i 2 f1;2;3g) of Fig. 2: A schematic of the SRS and a schematic of a single section. the SRS, as shown in Fig. 2-a. It depicts three mechanically identical variable length actuators (PMAs) with an unac- tuated length Li0 2 R and length change li j (t) 2 R, where all the gaits. This is the first SRS to utilize spatial bending j 2 f1;2;3g is the actuator index, and t is the time. Hence, capability and demonstrate meaningful locomotion (using the length of an actuator at any time is Li j = Li0 +li j(t). The inward/outward rolling gait) without wheels and utilizing the kinematic model of the proposed SRS can be formulated friction forces generated by skin-ground interactions. by extending the modal kinematics proposed by Godage et al. in [17]. Let the joint space vector of any ith soft robot T module be qi = [li1 (t); li2; li3 (t)] . Utilizing the results from II. SYSTEM MODEL [17], we can derive the homogeneous transformation matrix (HTM) at any point along the neutral axis of the ith soft A. Prototype Description 3 module, Ti 2 SE , as Fig. 1 shows the prototype of the proposed SRS. It is R (q ;x ) p (q ;x ) R (s ) p (d ) T (q ;x ) = i i i i i i z i x i (1) made of three serially attached soft bending modules (or i i i 0 1 0 1 sections). They are powered by McKibben type extending 3 3 mode pneumatic muscle actuators (PMA). These actuators where Ri 2 SO is the rotational matrix, pi 2 R is the proportionally extend the body to supplied pneumatic pres- position vector xi 2 [0;1] is a scalar to define points along sure up to 4 bars. In a single soft module, 3 PMAs are the soft module with 0, and 1 denotes the base and the p tip, and I3 is the rank 3 identity matrix. In addition to the assembled at 3 separation from each other to ensure sym- metric spatial bending and facilitate room to route pneumatic previous results in [17], note that we introduce two HTMs 3 supply lines within the module for a streamlined physical with Rz 2 SO is the rotation matrix about the +Z axis, and 3 0 profile required for a slender snake-like body. Each PMA px 2 R is the position offset along the +Z of Oi where has an unactuated length, Li0=0.15 m, and can extend by si 2 [0;2p]. 3 0.065 m at 4 bar pressure. Rigid 3D printed mounting frames Utilizing (1) with a floating coordinate system, Tb 2 SE , (made of ABS thermoplastic) are used to mount PMAs the complete kinematic model along the body of the snake at ri=0.0125 m from the centerline of soft modules (Fig. robot (Fig. 2-b) is given by 3 1). Similarly, laser-cut plastic constrainer plates of ri and 0.0025 m thickness are used along the soft modules’ length T(qb;q;x) = Tb (qb)∏Ti (qi;xi) i=1 to maintain PMAs parallel to soft modules’ central axis with R(q ;q;x) p(q ;q;x) a r clearance from the central axis. The constrainer plates = b b (2) i 0 1 also provide structural strength for this long and slender SRS to maintain its structural integrity during locomotion where qb = [xb;yb;zb;a;b;g] are the parameters of the float- and generate reaction forces required for locomotion. All ing coordinate system with [xb;yb;zb] denote the translation actuators are bundled within the soft module as a single and [a;b;g] denote the XYZ Euler angle offset of the base of unit, similar to the continuum sections reported in [16]. The module 1, i.e., the origin of the robot coordinate frame, with 9 pressure differential among PMAs of a soft module causes respect to fOg. The composite vector q = [q1;q2;;q3] 2 R the module to bend in any direction or extend axially. Thus and x = [0;3] 2 R. we can control the bends synchronously in order to generate various types of robot locomotion gaits. Soft modules are III. TRAJECTORY GENERATION p then connected via the mounting frames at a 3 offset to each In this work, we consider serpentine, inward rolling, other to create the SRS (Fig. 1). Finally, the SRS is wrapped and outward rolling locomotion gaits, which are cyclic in with rubber skin, and without the pneumatic supply lines, it nature. We can mathematically model these gaits associated weighs close to 0.3 kg. with different locomotion gaits to generate the taskspace point along the curve. We then derive a local coordinate frame with respect to the inertial frame at those points.
Load more

Recommended publications
  • Traversing Tight Tunnels—Implementing an Adaptive Concertina Gait in a Biomimetic Snake Robot Henry C
    Earth and Space 2018 158 Traversing Tight Tunnels—Implementing an Adaptive Concertina Gait in a Biomimetic Snake Robot Henry C. Astley1 1Biomimicry Research and Innovation Center, Dept. of Biology and Polymer Science, Univ. of Akron, 235 Carroll St., Akron, OH 44325-3908. E-mail: [email protected] ABSTRACT Snakes move through cluttered habitats and tight spaces with extraordinary ease, and consequently snake robots are a popular design for such situations. The remarkable locomotor performance of snakes is due in part to their diversity of locomotor modes for addressing a range of environmental challenges. Concertina locomotion consists of alternating periods of static anchoring and movement along the snake’s body, and is used to negotiate narrow spaces such as tunnels or bare branches. However, concertina locomotion has rarely been implemented in snake robots. In this paper, the anchor formation process in live snakes during concertina locomotion is quantified and used to implement concertina locomotion in a snake robot, with automatic detection of the width of the tunnel walls to modulate the waveform. This allows effective concertina locomotion in tunnels of unknown width, without prior knowledge of tunnel geometry, expanding the range of gaits in snake robots. INTRODUCTION The elongate, limbless body plan is extremely common throughout nature, in both vertebrate and invertebrates alike (Pechenik, J. A. 2005; Pough, F. H. et al. 2002), and has evolved independently numerous times (Gans, C 1975). Indeed, within lizards (Order Squamata) alone there are over two dozen independent evolutions of limblessness or functional limblessness (Wiens, J. J. et al. 2006). Snakes are by far the most successful limbless taxon, with a near-global distribution, nearly 3000 species, and a wide range of ecological niches and habitats (Pough, F.
    [Show full text]
  • Introduction to 2D-Animation Working Practice
    Prelims-K52054.qxd 2/6/07 5:18 PM Page i Character Animation: 2D Skills for Better 3D This page intentionally left blank Prelims-K52054.qxd 2/6/07 5:18 PM Page iii Character Animation: 2D Skills for Better 3D Second edition Steve Roberts AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Focal Press is an imprint of Elsevier Prelims-K52054.qxd 2/6/07 5:18 PM Page iv This eBook does not include ancillary media that was packaged with the printed version of the book. Focal Press is an imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP, UK 30 Corporate Drive, Suite 400, Burlington, MA 01803, USA First published 2004 Second edition 2007 Copyright © 2007, Steve Roberts. Published by Elsevier Ltd. All rights reserved The right of Steve Roberts to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (ϩ44) (0) 1865 843830; fax (ϩ44) (0) 1865 853333; e-mail: [email protected]. Alternatively you can submit your request online by visiting the Elsevier web site at http://elsevier.com/locate/permissions, and selecting Obtaining permission to use Elsevier material Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or idead contained in the material herein.
    [Show full text]
  • Limbless Locomotion: Learning to Crawl with a Snake Robot
    Limbless Locomotion: Learning to Crawl with a Snake Robot Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Robotics Kevin J. Dowling Advised by William L. Whittaker The Robotics Institute Carnegie Mellon University 5000 Forbes Avenue Pittsburgh, PA 15213 December 1997 This research was supported in part by NASA Graduate Fellowships 1994, 1995 and 1996. The views and conclusions contained in this document are those of the author and should not be interpreted as representing the official policies, either expressed or implied, of NASA or the U.S. Government. Ó 1997 by Kevin Dowling. Limbless Locomotion: Learning to Crawl Snake robots that learn to locomote Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Robotics by Kevin Dowling The Robotics Institute, Carnegie Mellon University, Pittsburgh, PA 15213 Robots can locomote using body motions; not wheels or legs. Natural analogues, such as snakes, although capable of such locomotion, are understood only in a qualitative sense and the detailed mechanics, sensing and control of snake motions are not well understood. Historically, mobile vehicles for terrestrial use have either been wheeled, tracked or legged. Prior art reveals several serpentine locomotor efforts, but there is little in the way of practical mechanisms and flexible control for limbless locomoting devices. Those mechanisms that exist in the laboratory exhibit only the rough features of natural limbless locomotors such as snakes. The motivation for this work stems from environments where traditional machines are precluded due to size or shape and where appendages such as wheels or legs cause entrapment or failure.
    [Show full text]
  • Adaptive Behaviour
    ADAPTIVE BEHAVIOUR Structure Introduction Objectives Colouration Source ofColour in Animals Colour Perception Adaptive Colouration Mimicry Types of Min~icty Different Forms of Mimicry Bioluminescence Luminous Organs in Fish Bioluminescent Molecules Mechanism of Bioluminescence Colour and Type of Emitted Light Significance of Bioluminescence Defence in Animals Adaptations for Defence Various Means of Defence in Animals Territorial Deknce Echolocation Sonar or Echolocation in Bats . Echolocation in Aquatic Mammals Echolocation in Birds Locomotion in Vertebrates Basic Locomotion Plans Locomotion in Water Locomotion in Air Locomotion on Ground Scansorial Locomotion Summary Terminal Questions Answers 16.1 INTRODUCTION In the earlier two units we attempted to answer the proximate question. How do animals behave in different ways in terms of genetic hormonal, neuronal and expenential differences among individuals. In this unit we seek ultimate answers i.e. the adaptive value of a particular behaviour. Adaptation is a fact of nature. Organisms are equipped in a variety of ways to survive successfully in their environment. This fitness to live under specific environmental L conditions is conferred on organisms through the interaction of variation and Natural Selection. Consequently all heritable adaptive changes are evolutionary changes. The pressing need for survival in organisms has resulted in the evolution of a variety of strategies for (a) luring the prey for food; (b) attracting the mate for reproduction, and (c) defending oneself from predators. These strategies are related to the habitat of the animal. For example, in the darkness of caves, bats and cave birds navigate and hunt through I echolocation. In the abyssmal depths of the sea, fishes emit various patterns of light for j the purposes of schooling, navigating and finding conspecific mates and food.
    [Show full text]
  • THOUGHT EXPERIMENTS Thispage Intentionally !Efi Blank THOUGHT EXPERIMENTS
    ROY A. SORENSEN THOUGHT EXPERIMENTS Thispage intentionally !efi blank THOUGHT EXPERIMENTS ROY A. SORENSEN OXFORD UNIVERSITY PRESS New York Oxford Oxford University Press Oxford New York Athens Auckland Bangkok Bogota Buenos Aires Calcutta Cape Town Chennai Dar es Salaam Delhi Florence Hong Kong Istanbul Karachi Kuala Lumpur Madrid Melbourne Mexico City Mumbai Nairobi Paris Săo Paulo Singapore Taipei Tokyo Toronto Warsaw and associated companies in Berlin lbadan Copyright © 1992 by Roy A. Sorensen First published in 1992 by Oxford University Press, Inc. 198 Madison Av enue, New York, New York 10016 First Issued as an Oxford University Press paperback, 1998 Oxford is a registered trademark of Oxford University Press, !ne. AU rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of Oxford University Press. Library of Congress Cataloging-in-Publication Data Sorensen, Roy A. Thought expriments Roy A. Sorensen p. cm. Includes bibliographica1 references and index. ISBN 0-19-507422-X ISBN 0-19-512913-X (pbk.) 1 Thought and thinking. 2. Logic 3. Philosophy and science 1. Title B105.T54S67 1992 !01-dc20 9136760 1357 986 42 Printed in the United States of America on acid-free paper For Julia, a woman of fine distinctions Thispage intentionally !efi blank ACKNOWLEDG MENTS This book has indebted me to many people. The first group consists of the individuals who attended colloquia given at the Graduate Center of the City University of New Yo rk, Columbia University, Dartmouth College, Rutgers University, the State University of New Yo rk at Stony Brook, Virginia Tech, and the 1990 lnter-University Conference for Philosophy of Science in Du­ brovnik.
    [Show full text]
  • S41467-019-13405-W OPEN Comparative Analysis of Squamate Brains Unveils Multi-Level Variation in Cerebellar Architecture Associated with Locomotor Specialization
    ARTICLE https://doi.org/10.1038/s41467-019-13405-w OPEN Comparative analysis of squamate brains unveils multi-level variation in cerebellar architecture associated with locomotor specialization Simone Macrì 1, Yoland Savriama 1, Imran Khan1 & Nicolas Di-Poï 1* Ecomorphological studies evaluating the impact of environmental and biological factors on the brain have so far focused on morphology or size measurements, and the ecological 1234567890():,; relevance of potential multi-level variations in brain architecture remains unclear in verte- brates. Here, we exploit the extraordinary ecomorphological diversity of squamates to assess brain phenotypic diversification with respect to locomotor specialization, by integrating single-cell distribution and transcriptomic data along with geometric morphometric, phylo- genetic, and volumetric analysis of high-definition 3D models. We reveal significant changes in cerebellar shape and size as well as alternative spatial layouts of cortical neurons and dynamic gene expression that all correlate with locomotor behaviours. These findings show that locomotor mode is a strong predictor of cerebellar structure and pattern, suggesting that major behavioural transitions in squamates are evolutionarily correlated with mosaic brain changes. Furthermore, our study amplifies the concept of ‘cerebrotype’, initially proposed for vertebrate brain proportions, towards additional shape characters. 1 Program in Developmental Biology, Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland. *email: nicolas.di-poi@helsinki.fi
    [Show full text]
  • Consequences of Abiotic and Biotic Factors on Limbless Locomotion
    MIAMI UNIVERSITY The Graduate School Certificate for Approving the Dissertation We hereby approve the Dissertation of Gary W. Gerald, II Candidate for the Degree: Doctor of Philosophy ___________________________________________ Director (Dennis L. Claussen) ___________________________________________ Reader (Alan B. Cady) ___________________________________________ Reader (Phyllis Callahan) ___________________________________________ (Nancy G. Solomon) ___________________________________________ Graduate School Representative (Robert L. Schaefer) ABSTRACT CONSEQUENCES OF ABIOTIC AND BIOTIC FACTORS ON LIMBLESS LOCOMOTION Gary W. Gerald II Snakes have the ability to move in a variety of ways depending on the habitat in which they are moving. All of these modes require some sort of lateral bending of the elongate body to generate the required force necessary for propulsion. However, the biomechanical mechanisms of each mode of limbless movement differ substantially among each other. Despite the potential importance of using multiple modes of movement in different ecological situations, we know very little about the influence of abiotic and biotic factors on multiple locomotor modes in these animals. The goal of this dissertation was to examine how temperature, habitat usage, and morphology affect four of the most common modes of limbless locomotion (lateral undulation, concertina, swimming, and arboreal) and shed light on the question of what ecological conditions most likely contributed to limb reduction in the early snake ancestor. The first chapter assessed the influence of temperature on different modes of locomotion. Decreasing temperature limits performance of each mode differently because of differences in the underlying physiological mechanisms governing each mode. The second chapter closely examined the combined effects of temperature and perch diameter on the speed and balance of limbless arboreal locomotion.
    [Show full text]
  • Analysis and Experiments for Tendril-Type Robots Lara Cowan Clemson University, [email protected]
    Clemson University TigerPrints All Theses Theses 5-2008 Analysis and Experiments for Tendril-Type Robots Lara Cowan Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Part of the Robotics Commons Recommended Citation Cowan, Lara, "Analysis and Experiments for Tendril-Type Robots" (2008). All Theses. 325. https://tigerprints.clemson.edu/all_theses/325 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. ANALYSIS AND EXPERIMENTS FOR TENDRIL-TYPE ROBOTS A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Computer Engineering by Lara Suzanne Cowan May 2008 Accepted by: Dr. Ian D. Walker, Committee Chair Dr. Darren Dawson Dr. Stan Birchfield i ABSTRACT New models for the Tendril continuous backbone robot, and other similarly constructed robots, are introduced and expanded upon in this thesis. The ability of the application of geometric models to result in more precise control of the Tendril manipulator is evaluated on a Tendril prototype. We examine key issues underlying the design and operation of ―soft‖ robots featuring continuous body (―continuum‖) elements. Inspiration from nature is used to develop new methods of operation for continuum robots. These new methods of operation are tested in experiments to evaluate their effectiveness and potential. ii DEDICATION To my parents and teachers, whom I could not have done this without, and the inspiration of science fiction.
    [Show full text]
  • Technology Assessment of Autonomous Intelligent Bipedal and Other Legged Robots
    TECHNOLOGY ASSESSMENT OF AUTONOMOUS INTELLIGENT BIPEDAL AND OTHER LEGGED ROBOTS FINAL REPORT Contract Number MDA972-02-M-0025 Submitted To: Dr. Alan Rudolph Defense Sciences Office Defense Advanced Research Projects Agency 3701 North Fairfax Drive Arlington, Virginia 22203-1714 Phone: (703)-696-2240 Fax: (703)-696-3999 [email protected] Submitted By: Dr. Robert Finkelstein, President Robotic Technology Inc. 11424 Palatine Drive Potomac, Maryland 20854-1451 Phone: (301)-983-4194 Fax: (301)-983-3921 [email protected] And Dr. James Albus, Senior NIST Fellow Intelligent Systems Division National Institute of Standards and Technology Building 220, Room B124 Gaithersburg, Maryland 20899-0001 Phone: (301)-975-3418 Fax: (301)-990-9688 [email protected] Revised 13 May 2003 & 21 November 2004 CONTENTS Section Page I. Executive Summary, Conclusions, and Recommendations 2 1.0 Purpose 5 2.0 Background 5 3.0 Expert Panel 10 4.0 Expert Survey Results 36 5.0 User Survey Results 53 6.0 Metrics for Humanoid and Legged Robots 63 7.0 Functional Analysis 69 8.0 State of Humanoid and Legged Robot Technology 89 9.0 Roadmap 105 Appendix A: Prospective and Actual Survey Experts 113 Appendix B: Survey Form for Survey of Robot Experts 122 Appendix C: Aggregated Expert Survey Results 130 Appendix D: User Survey Participants 188 Appendix E: Survey Form for Survey of Robot Users 190 Appendix F: Aggregated User Survey Results 197 Appendix G: Metrics Figures 231 Appendix H: Functional Diagram of Any Legged Robot 238 Appendix I: References 239 1 I. EXECUTIVE SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS I.1 Purpose The purpose of this project is to perform a technology assessment of supervised autonomous intelligent humanoid robots, to examine current technology and systems to determine the feasibility of humanoid robots, and other legged robots, for militarily useful behavior in the near to far term (e.g., years 2002 - 2030) and to provide a technology roadmap for developing and demonstrating a humanoid robot for a selected military mission.
    [Show full text]
  • The Energetic Cost of Limbless Locomotion
    Reprint Series 3 August 1990, Volume 249, pp. 524-527 The Energetic Cost of Limbless Locomotion MICHAELWALTON, BRUCE C. JAYNE, AND ALBERTF. BENNETT Copyright 63 1990 by the American Association for the Advancement of Science The Energetic Cost of Limbless Locomotion The net energetic cost of terrestrial locomotion by the snake Coluber constrictor, moving by lateral undulation, is equivalent to the net energetic cost of running by limbed animals (arthropods, lizards, birds, and mammals) of similar size. In contrast to lateral undulation and limbed locomotion, concertina locomotion by Coluber is more energet- ically expensive. The findings donot support the widely held notion that the energetic cost of terrestrial locomotion by limbless animals is less than that of limbed animals. PECIES WITH REDUCED LIMBS OR NO contact with the ground (4, 12). In narrow limbs and elongate bodies have passageways such as tunnels, snakes often Sevolved independently from limbed perform concertina locomotion exclusively antecedents in several groups of vertebrates: (4). Snakes performing concertina locomo- salamanders, caecilians, amphisbaenians, liz- tion stop periodically, and certain parts of ards, and snakes (1). An important factor the body are moved forward while others proposed to explain the evolution of limb- maintain static contact with the ground. In lessness is its presumptively low energetic passageways, snakes alternately press them- cost, such that energetic expenditure during selves against the sides by forming a series of locomotion by limbless animals is expected bends and then extend themselves forward to be less than that of limbed animals of from the region of static contact (4, 13). In similar size (1,2).
    [Show full text]
  • Functional Analysis of the Motor Circuit of Juvenile Caenorhabditis Elegans
    Functional Analysis of the Motor Circuit of Juvenile Caenorhabditis elegans by Yangning Lu A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Physiology University of Toronto © Copyright by Yangning Lu 2020 Functional Analysis of the Motor Circuit of Juvenile Caenorhabditis elegans Yangning Lu Doctor of Philosophy Department of Physiology University of Toronto 2020 Abstract Caenorhabditis elegans generates alternating dorsal-ventral bending waves across developmental stages. The overall level of dorsal and ventral muscle output is symmetric. In adults, this behavioral symmetry correlates with anatomy symmetry: distinct pools of cholinergic motor neurons activate dorsal and ventral body wall muscles, whereas distinct pools of GABAergic motor neurons contra-laterally inhibit dorsal and ventral muscles, respectively. However, in the first stage larva (L1), cholinergic motor neurons only make neuromuscular junctions to the dorsal muscle, and GABAergic motor neurons to the ventral muscle. How does an asymmetric motor circuit produce symmetric motor output? In the past five years, my colleagues and I undertook anatomical and functional analyses of the L1 larva motor circuit to address this question. First, my colleagues fully reconstructed the connectivity of a complete L1 larva, from which we identified all candidate cellular components for muscle activity. Next, to elucidate the functional contribution of these candidates, I developed a novel all-optical manipulation methodology that allows fast and systemic probing of functional connections of neural circuits. Third, I led the effort to combine free-moving calcium ii imaging, cellular ablation, chemogenetics, optogenetics, and all-optical interrogation to pinpoint mechanisms for the symmetric L1 muscle output.
    [Show full text]
  • Snakelike Robots Locomotions Control
    Course 5: Mechatronics - Foundations and Applications Snakelike robots locomotions control Oleg Shmakov May 29, 2006 Abstract In this paper you can ¯nd a review of snakelike robot constructions as well as report on biometrical requisites for development such devices and give a some description of mechanical and mathematical models snakes movement. Point out on existence rational model of snakes's movement. This model is very helpful to develop e®ective algorithms to control locomotion snakelike robots witch have no wheels. In report described the real hardware snakelike robot locomotion control and give a detailed description of snakelike robot developed in Scienti¯c Research and Design Institute of Robotics and Technical Cybernetics in Saint Petersburg, Russia. This model have already performed showing di®erent modes of locomotion. 1 Contents 1 Introduction 3 2 Why snakelike robots? 3 2.1 Advantages . 3 2.2 Applications . 4 3 Biomechanics of snake 4 3.1 Bionics . 4 3.2 Locomotion modes . 5 4 Review: mechanic model of snakelike robots 8 4.1 Hirose . 8 4.2 Burdick and Chirikjian . 11 4.3 Dowling . 13 4.4 Howie Choset - CMU . 13 4.5 Dobrolyubov A.I. 15 4.6 Ivanov A.A. 15 5 Mathematical model of snakelike robots 18 5.1 Genetic algorithms . 18 5.2 The determined approach . 20 6 Hardware realization control 22 7 Snakelike robot CRDI RTC 22 8 Conclusions 26 2 1 Introduction Nowadays snakelike robots are an actively upcoming area in robotics. Frequently the term snake like robot is applied to all hyper redundant robots; those are consisted from modules connected by active or passive joints.
    [Show full text]