Passive Variable Compliance for Dynamic Legged Robots
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Kinematic Modeling of a Rhex-Type Robot Using a Neural Network
Kinematic Modeling of a RHex-type Robot Using a Neural Network Mario Harpera, James Paceb, Nikhil Guptab, Camilo Ordonezb, and Emmanuel G. Collins, Jr.b aDepartment of Scientific Computing, Florida State University, Tallahassee, FL, USA bDepartment of Mechanical Engineering, Florida A&M - Florida State University, College of Engineering, Tallahassee, FL, USA ABSTRACT Motion planning for legged machines such as RHex-type robots is far less developed than motion planning for wheeled vehicles. One of the main reasons for this is the lack of kinematic and dynamic models for such platforms. Physics based models are difficult to develop for legged robots due to the difficulty of modeling the robot-terrain interaction and their overall complexity. This paper presents a data driven approach in developing a kinematic model for the X-RHex Lite (XRL) platform. The methodology utilizes a feed-forward neural network to relate gait parameters to vehicle velocities. Keywords: Legged Robots, Kinematic Modeling, Neural Network 1. INTRODUCTION The motion of a legged vehicle is governed by the gait it uses to move. Stable gaits can provide significantly different speeds and types of motion. The goal of this paper is to use a neural network to relate the parameters that define the gait an X-RHex Lite (XRL) robot uses to move to angular, forward and lateral velocities. This is a critical step in developing a motion planner for a legged robot. The approach taken in this paper is very similar to approaches taken to learn forward predictive models for skid-steered robots. For example, this approach was used to learn a forward predictive model for the Crusher UGV (Unmanned Ground Vehicle).1 RHex-type robot may be viewed as a special case of skid-steered vehicle as their rotating C-legs are always pointed in the same direction. -
Towards Pronking with a Hexapod Robot
Towards pronking with a hexapod robot Dave McMordie Department of Electrical Engineering McGill University, Montreal, Canada July, 2002 A thesis submitted to the Faculty of Graduate 5tudies and Research in partial fulfillment of the requirements of the degree Master of Engineering © Dave McMordie, 2002 National Library Bibliothèque nationale 1+1 of Canada du Canada Acquisitions and Acquisisitons et Bibliographie Services services bibliographiques 395 Wellington Street 395, rue Wellington Ottawa ON K1A DN4 Ottawa ON K1A DN4 Canada Canada Your file Votre référence ISBN: 0-612-85890-1 Our file Notre référence ISBN: 0-612-85890-1 The author has granted a non L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts from it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou aturement reproduits sans son permission. autorisation. Canada Abstract RHex is a robotic hexapod with springy legs and just six actuated degrees of freedom. This work presents the development of a pronking gait for RHex, extending its efficiency and speed by exploiting its springy legs for hopping. -
Design and Control of a Large Modular Robot Hexapod
Design and Control of a Large Modular Robot Hexapod Matt Martone CMU-RI-TR-19-79 November 22, 2019 The Robotics Institute School of Computer Science Carnegie Mellon University Pittsburgh, PA Thesis Committee: Howie Choset, chair Matt Travers Aaron Johnson Julian Whitman Submitted in partial fulfillment of the requirements for the degree of Master of Science in Robotics. Copyright © 2019 Matt Martone. All rights reserved. To all my mentors: past and future iv Abstract Legged robotic systems have made great strides in recent years, but unlike wheeled robots, limbed locomotion does not scale well. Long legs demand huge torques, driving up actuator size and onboard battery mass. This relationship results in massive structures that lack the safety, portabil- ity, and controllability of their smaller limbed counterparts. Innovative transmission design paired with unconventional controller paradigms are the keys to breaking this trend. The Titan 6 project endeavors to build a set of self-sufficient modular joints unified by a novel control architecture to create a spiderlike robot with two-meter legs that is robust, field- repairable, and an order of magnitude lighter than similarly sized systems. This thesis explores how we transformed desired behaviors into a set of workable design constraints, discusses our prototypes in the context of the project and the field, describes how our controller leverages compliance to improve stability, and delves into the electromechanical designs for these modular actuators that enable Titan 6 to be both light and strong. v vi Acknowledgments This work was made possible by a huge group of people who taught and supported me throughout my graduate studies and my time at Carnegie Mellon as a whole. -
Dynamically Diverse Legged Locomotion for Rough Terrain
Dynamically diverse legged locomotion for rough terrain The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Byl, Katie, and Russ Tedrake. “Dynamically Diverse Legged Locomotion for Rough Terrain.” Proceedings of the 2009 IEEE International Conference on Robotics and Automation, Kobe International Conference Center, Kobe, Japan, May 12-17, 2009 1607-1608. © Copyright 2009 IEEE. As Published http://dx.doi.org/10.1109/ROBOT.2009.5152757 Publisher Institute of Electrical and Electronics Engineers Version Final published version Citable link http://hdl.handle.net/1721.1/64752 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. 2009 IEEE International Conference on Robotics and Automation Kobe International Conference Center Kobe, Japan, May 12-17, 2009 Dynamically Diverse Legged Locomotion for Rough Terrain Katie Byl and Russ Tedrake Abstract— In this video, we demonstrate the effectiveness of which aim toward precise foot placement often traverse a kinodynamic planning strategy that allows a high-impedance terrain by using relatively slow, deliberate gaits [3], [4], [10], quadruped to operate across a variety of rough terrain. At one [8], [6]. In this video we demonstrate a control approach extreme, the robot can achieve precise foothold selection on intermittent terrain. More surprisingly, the same inherently- which can achieve both precise foot placement, as illustrated stiff robot can also execute highly dynamic and underactuated in Figure 1, and highly dynamic and fast motions, such as motions with high repeatability. -
Design of a Multi-Directional Variable Stiffness Leg for Dynamic Running
University of Pennsylvania ScholarlyCommons Departmental Papers (ESE) Department of Electrical & Systems Engineering 2007 DESIGN OF A MULTI-DIRECTIONAL VARIABLE STIFFNESS LEG FOR DYNAMIC RUNNING Kevin C. Galloway University of Pennsylvania, [email protected] Jonathan E. Clark Florida State University, [email protected] Daniel E. Koditschek University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/ese_papers Part of the Engineering Commons Recommended Citation Kevin C. Galloway, Jonathan E. Clark, and Daniel E. Koditschek, "DESIGN OF A MULTI-DIRECTIONAL VARIABLE STIFFNESS LEG FOR DYNAMIC RUNNING", . January 2007. @inproceedings{ Galloway.07, Author = {Galloway, K.C. and Clark, J.E. and Koditschek, D.E.}, Title = {Design of a Multi-Directional Variable Stiffness Leg for Dynamic Runnings}, BookTitle = {ASME Int. Mech. Eng. Congress and Exposition}, Year = {2007}} This paper is posted at ScholarlyCommons. https://repository.upenn.edu/ese_papers/508 For more information, please contact [email protected]. DESIGN OF A MULTI-DIRECTIONAL VARIABLE STIFFNESS LEG FOR DYNAMIC RUNNING Abstract Recent developments in dynamic legged locomotion have focused on encoding a substantial component of leg intelligence into passive compliant mechanisms. One of the limitations of this approach is reduced adaptability: the final leg mechanism usually performs optimally for a small range of conditions (i.e. a certain robot weight, terrain, speed, gait, and so forth). For many situations in which a small locomotion system experiences a change in any of these conditions, it is desirable to have a variable stiffness leg to tune the natural frequency of the system for effective gait control. In this paper, we present an overview of variable stiffness leg spring designs, and introduce a new approach specifically for autonomous dynamic legged locomotion. -
Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: a Review Jun He and Feng Gao*
He and Gao Chin. J. Mech. Eng. (2020) 33:79 https://doi.org/10.1186/s10033-020-00485-9 Chinese Journal of Mechanical Engineering REVIEW Open Access Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: A Review Jun He and Feng Gao* Abstract Multilegged robots have the potential to serve as assistants for humans, replacing them in performing dangerous, dull, or unclean tasks. However, they are still far from being sufciently versatile and robust for many applications. This paper addresses key points that might yield breakthroughs for highly dynamic multilegged robots with the abilities of running (or jumping and hopping) and self-balancing. First, 21 typical multilegged robots from the last fve years are surveyed, and the most impressive performances of these robots are presented. Second, current developments regarding key technologies of highly dynamic multilegged robots are reviewed in detail. The latest leg mechanisms with serial-parallel hybrid topologies and rigid–fexible coupling confgurations are analyzed. Then, the development trends of three typical actuators, namely hydraulic, quasi-direct drive, and serial elastic actuators, are discussed. After that, the sensors and modeling methods used for perception are surveyed. Furthermore, this paper pays special attention to the review of control approaches since control is a great challenge for highly dynamic multilegged robots. Four dynamics-based control methods and two model-free control methods are described in detail. Third, key open topics of future research concerning the mechanism, actuation, perception, and control of highly dynamic multilegged robots are proposed. This paper reviews the state of the art development for multilegged robots, and discusses the future trend of multilegged robots. -
Vision-Based Autonomous Underwater Vehicle Navigation in Poor Visibility Conditions Using a Model-Free Robust Control
Hindawi Publishing Corporation Journal of Sensors Volume 2016, Article ID 8594096, 16 pages http://dx.doi.org/10.1155/2016/8594096 Research Article Vision-Based Autonomous Underwater Vehicle Navigation in Poor Visibility Conditions Using a Model-Free Robust Control Ricardo Pérez-Alcocer,1 L. Abril Torres-Méndez,2 Ernesto Olguín-Díaz,2 and A. Alejandro Maldonado-Ramírez2 1 CONACYT-Instituto Politecnico´ Nacional-CITEDI, 22435 Tijuana, BC, Mexico 2Robotics and Advanced Manufacturing Group, CINVESTAV Campus Saltillo, 25900 Ramos Arizpe, COAH, Mexico Correspondence should be addressed to L. Abril Torres-Mendez;´ [email protected] Received 25 March 2016; Revised 5 June 2016; Accepted 6 June 2016 Academic Editor: Pablo Gil Copyright © 2016 Ricardo Perez-Alcocer´ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper presents a vision-based navigation system for an autonomous underwater vehicle in semistructured environments with poor visibility. In terrestrial and aerial applications, the use of visual systems mounted in robotic platforms as a control sensor feedback is commonplace. However, robotic vision-based tasks for underwater applications are still not widely considered as the images captured in this type of environments tend to be blurred and/or color depleted. To tackle this problem, we have adapted the color space to identify features of interest in underwater images even in extreme visibility conditions. To guarantee the stability of the vehicle at all times, a model-free robust control is used. We have validated the performance of our visual navigation system in real environments showing the feasibility of our approach. -
Geometric Optimization of a Self-Adaptive Robotic Leg
Transactions of the Canadian Society for Mechanical Engineering Geometric Optimization of a Self-Adaptive Robotic Leg Journal: Transactions of the Canadian Society for Mechanical Engineering Manuscript ID TCSME-2017-0010.R1 Manuscript Type: Article Date Submitted by the Author: 16-Jan-2018 Complete List of Authors: Fedorov, Dmitri; Ecole Polytechnique de Montreal, Mechanical Engineering Birglen, Lionel; Ecole Polytechnique de Montreal, Mechanical Engineering Is the invited manuscript for consideration in a Special CCToMM 2017Draft Symposium Special Issue Issue? : Keywords: Underactuation, Linkage, Robotic Leg, Optimization, Planar Mechanism https://mc06.manuscriptcentral.com/tcsme-pubs Page 1 of 41 Transactions of the Canadian Society for Mechanical Engineering GEOMETRIC OPTIMIZATION OF A SELF-ADAPTIVE ROBOTIC LEG Dmitri Fedorov1, Lionel Birglen1 1Department of Mechanical Engineering, École Polytechnique de Montréal, Montréal, QC, Canada Email: [email protected]; [email protected] Draft CCToMM Mechanisms, Machines, and Mechatronics (M3) Symposium, 2017 1 https://mc06.manuscriptcentral.com/tcsme-pubs Transactions of the Canadian Society for Mechanical Engineering Page 2 of 41 ABSTRACT Inspired by underactuated mechanical fingers, this paper demonstrates and optimizes the self-adaptive capabilities of a 2-DOF Hoecken’s-Pantograph robotic leg allowing it to overcome unexpected obstacles en- countered during its swing phase. A multi-objective optimization of the mechanism’s geometric parameters is performed using a genetic algorithm to highlight the trade-off between two conflicting objectives and se- lect an appropriate compromise. The first of those objective functions measures the leg’s passive adaptation capability through a calculation of the input torque required to initiate the desired sliding motion along an obstacle. -
Learning Flexible and Reusable Locomotion Primitives for a Microrobot Brian Yang, Grant Wang, Roberto Calandra, Daniel Contreras, Sergey Levine, and Kristofer Pister
IEEE ROBOTICS AND AUTOMATION LETTERS. PREPRINT VERSION. ACCEPTED JANUARY, 2018 1 Learning Flexible and Reusable Locomotion Primitives for a Microrobot Brian Yang, Grant Wang, Roberto Calandra, Daniel Contreras, Sergey Levine, and Kristofer Pister Abstract—The design of gaits for robot locomotion can be a daunting process which requires significant expert knowledge and engineering. This process is even more challenging for robots that do not have an accurate physical model, such as compliant or micro-scale robots. Data-driven gait optimization provides an automated alternative to analytical gait design. In this paper, we propose a novel approach to efficiently learn a wide range of locomotion tasks with walking robots. This approach formalizes locomotion as a contextual policy search task to collect Figure 1: The six-legged micro walker considered in our study data, and subsequently uses that data to learn multi-objective locomotion primitives that can be used for planning. As a proof- as a CAD model (left) and an assembled prototype (right). of-concept we consider a simulated hexapod modeled after a recently developed microrobot, and we thoroughly evaluate the environments designed to simulate dynamics at this scale are performance of this microrobot on different tasks and gaits. Our generally unequipped for usage in robotics contexts. Addition- results validate the proposed controller and learning scheme ally, working with microrobots can place severe limitations on on single and multi-objective locomotion tasks. Moreover, the experimental simulations show that without any prior knowledge the number of iterations as trials become much more time- about the robot used (e.g., dynamics model), our approach is consuming and expensive to run. -
Towards a 3G Crawling Robot Through the Integration of Microrobot Technologies*
Towards a 3g Crawling Robot through the Integration of Microrobot Technologies* Ranjana Sahai, Srinath Avadhanula, Richard Groff, Erik Steltz, Robert Wood, and Ronald S. Fearing Electrical Engineering and Computer Science Department University of California, Berkeley Berkeley, CA 94720 USA [email protected] or [email protected] Abstract - This paper discusses the biomimetic design and brief descriptions of the various integrated technologies, and, assembly of a 3g self-contained crawling robot fabricated finally, give our results and conclusions from following this through the integrated use of various microrobot technologies. process. The hexapod structure is designed to move in an alternating tripod gait driven by two piezoelectric actuators connected by II. ROBOT DESIGN sliding plates to two sets of three legs. We present results of both the kinematic and static analyses of the driving mechanism that A. Background essentially consists of three slider cranks in series. This analysis The development of a robot with legs as opposed to confirmed the force differential needed to propel the device. We wheels (nature’s solution for adapting to various types of then review various other microrobot technologies that have been terrain) has been investigated as far back as 1940. Reference developed including actuator design and fabrication, power and [3] provides a review of some of these various designs over control electronics design, programming via a finite state the years. Some other designs of particular note from the machine, and the development of bioinspired fiber arrays. These point of view of biomimetic structures and terrain adaptability technologies were then successfully integrated into the device. -
Design and Synthesis of Mechanical Systems with Coupled Units Yang Zhang
Design and synthesis of mechanical systems with coupled units Yang Zhang To cite this version: Yang Zhang. Design and synthesis of mechanical systems with coupled units. Mechanical engineering [physics.class-ph]. INSA de Rennes, 2019. English. NNT : 2019ISAR0004. tel-02307221 HAL Id: tel-02307221 https://tel.archives-ouvertes.fr/tel-02307221 Submitted on 7 Oct 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THESE DE DOCTORAT DE L’INSA RENNES COMUE UNIVERSITE BRETAGNE LOIRE ECOLE DOCTORALE N° 602 Sciences pour l'Ingénieur Spécialité : « Génie Mécanique » Par « Yang ZHANG » « DESIGN AND SYNTHESIS OF MECHANICAL SYSTEMS WITH COUPLED UNITS » Thèse présentée et soutenue à Rennes, le 19.04.2019 Unité de recherche : LS2N Thèse N° : 19ISAR 06 / D19 - 06 Rapporteurs avant soutenance : Composition du Jury : BEN OUEZDOU Féthi WENGER Philippe Professeur des Universités, UVSQ, Versailles Directeur de Recherche CNRS, LS2N Nantes / Président DELALEAU Emmanuel BEN OUEZDOU Féthi Professeur des Universités, ENIB, Brest Professeur des Universités, UVSQ, Versailles -
Development of Six Legged Spider Robot Using Klann Mechanism with the Integration
International Journal of Innovative Research in Science, Engineering and Technology (IJIRSET) | e-ISSN: 2319-8753, p-ISSN: 2320-6710| www.ijirset.com | Impact Factor: 7.512| || Volume 9, Issue 8, August 2020 || Development of Six Legged Spider Robot Using Klann Mechanism with the Integration of Wheel for varied Terrain Balaji F Savanoor1, Pavana A2, Nikhil P Purandar3, Ashwin S Srivatsa4, Raghavendra N5, Harish A6 U.G. Student, Dept. of Mechanical Engineering, BNM Institute of Technology, Bangalore, Karnataka, India1,2,3,4 Associate Professor, Dept. of Mechanical Engineering, BNM Institute of Technology, Bangalore, Karnataka, India5 Assistant Professor, Dept. of Mechanical Engineering, BNM Institute of Technology, Bangalore, Karnataka, India6 ABSTRACT: Wheel is the common mode of locomotive movement. But for the places like stair, uneven surfaces, the wheel movement is not suitable. The human beings moving easily on the stairs due to flexibility in the legs as it functions like links connected with joints. Various mechanisms are used with imitating the leg movements of animals for the rough terrain maneuver. Two most effective leg mechanisms used are JoeKlann’s mechanism which resembles a spider leg and Theo Jansen’s mechanism which resembles a human leg.This paper discussesabout the development of spider mechanism (Klan’s mechanism) for any rough terrain motions. By spider mechanism (Klann’s mechanism) with random movements it is possible to combine the moment of walking as well as wheel movement. The walking mechanism is well known for rough terrain movement and the wheel movement of the mechanism results in fast movement for smooth surfaces. The function of the controlling device is to identify the type of surface and change over to required feature to move forward.