Download or read book Gait Regulation Control Techniques for Robust Legged Locomotion written by Galen Clark Haynes and published by . This book was released on 2008 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "This thesis develops methods of control that allow a multi-legged robot to vary its stepping pattern, the gait of a robot, during locomotion. By constructing feedback control around the gaits a robot may use, we produce behaviors allowing a robot to switch amongst or return to certain gaits while performing feedback control during locomotion. Gait regulation is one specific aspect of gait-based control, and pertains to the use of a control system to monitor and regulate the desired gaits a robot may use. While some gait-based control laws may force a robot to deviate from a nominal gait, gait regulation seeks to return to--or switch amongst--desired gaits as required. After discussing the necessary topological effects of gait regulation control, as well as noting specific constraints that are unique to legged systems, this thesis proposes methods of gait regulation control that place attractors and repellors on a high-dimensional toroidal space, a space relevant to gait timings, in order to converge upon desired gaits. The primary contribution of this thesis is an efficient algorithmic approach to gait regulation that avoids dangerous leg timings while converging to desired gaits, as specified. The system actively manages the basins of convergence for various controllers to achieve a global vector policy directing a robot to certain desired gaits. This work is particularly applicable to four- and six-legged robots, on which a variety of interesting and useful gait timings exist. Specifically, we apply gait regulation to a climbing hexapod, on which we design a climbing behavior based upon a collection of reactive force control techniques, causing the robot to deviate from its desired gait. With gait regulation, the robot maintains use of its desired gaits, with the additional ability to actively transition amongst gaits while climbing."

Download or read book Robotics Research written by Cédric Pradalier and published by Springer. This book was released on 2011-04-21 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents a collection of papers presented at the 14th International Symposium of Robotic Research (ISRR). ISRR is the biennial meeting of the International Foundation of Robotic Research (IFRR) and its 14th edition took place in Lucerne, Switzerland, from August 31st to September 3rd, 2009. As for the previous symposia, ISRR 2009 followed up on the successful concept of a mixture of invited contributions and open submissions. Half of the 48 presentations were therefore invited contributions from outstanding researchers selected by the IFRR officers, and half were chosen among the 66 submissions after peer review. This selection process resulted in a truly excellent technical program which, we believe, featured some of the very best of robotic research. Out of the 48 presentations, the 42 papers which were finally submitted for publication are organized in 8 sections that encompass the major research orientations in robotics: Navigation, Control & Planning, Human-Robot Interaction, Manipulation and Humanoids, Learning, Mapping, Multi-Robot Systems, and Micro-Robotics. They represent an excellent snapshot of cutting-edge research in robotics and outline future directions.

Download or read book Policy Regularized Model Predictive Control Framework for Robust Legged Locomotion written by Gerardo Bledt and published by . This book was released on 2018 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel Policy Regularized Model Predictive Control (PR-MPC) framework is developed to allow general robust legged locomotion with the MIT Cheetah quadruped robot. The full system is approximated by a simple control model that retains the key nonlinearities characteristic to legged contact dynamics while reducing the complexity of the continuous dynamics. Nominal footstep locations and feedforward forces for controlling the robot's center of mass are designed from simple physics-based heuristics for steady state legged movement. By regularizing the predictive optimization with these policies, we can exploit the known dynamics of the system to bias the controller towards the steady state gait while remaining free to explore the cost space during transient behaviors and disturbances. The nonlinear optimization makes use of direct collocation on the simplified dynamics to pose the problem with a highly sparse structure for fast computation. A generalized approach to the controller design is independent from specific gait pattern and reference policy and allows stabilization of aperiodic locomotion. Simulation results show dynamic capabilities in a variety of gaits including trotting, bounding, and galloping, all without changing the set of algorithm parameters between experiments. Robustness to sensor and input noise, large push disturbances, and unstructured terrain demonstrate the ability of the predictive controller to adapt to uncertainty.

Download or read book Gait Optimization for Multi legged Walking Robots with Application to a Lunar Hexapod written by Daniel Chávez-Clemente and published by Stanford University. This book was released on 2011 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interest in using legged robots for a variety of terrestrial and space applications has grown steadily since the 1960s. At the present time, a large fraction of these robots relies on electric motors at the joints to achieve mobility. The load distributions inherent to walking, coupled with design constraints, can cause the motors to operate near their maximum torque capabilities or even reach saturation. This is especially true in applications like space exploration, where critical mass and power constraints limit the size of the actuators. Consequently, these robots can benefit greatly from motion optimization algorithms that guarantee successful walking with maximum margin to saturation. Previous gait optimization techniques have emphasized minimization of power requirements, but have not addressed the problem of saturation directly. This dissertation describes gait optimization techniques specifically designed to enable operation as far as possible from saturation during walking. The benefits include increasing the payload mass, preserving actuation capabilities to react to unforeseen events, preventing damage to hardware due to excessive loading, and reducing the size of the motors. The techniques developed in this work follow the approach of optimizing a reference gait one move at a time. As a result, they are applicable to a large variety of purpose-specific gaits, as well as to the more general problem of single pose optimization for multi-limbed walking and climbing robots. The first part of this work explores a zero-interaction technique that was formulated to increase the margin to saturation through optimal displacements of the robot's body in 3D space. Zero-interaction occurs when the robot applies forces only to sustain its weight, without squeezing the ground. The optimization presented here produces a swaying motion of the body while preserving the original footfall locations. Optimal displacements are found by solving a nonlinear optimization problem using sequential quadratic programming (SQP). Improvements of over 20% in the margin to saturation throughout the gait were achieved with this approach in simulation and experiments. The zero-interaction technique is the safest in the absence of precise knowledge of the contact mechanical properties and friction coefficients. The second part of the dissertation presents a technique that uses the null space of contact forces to achieve greater saturation margins. Interaction forces can significantly contribute to saturation prevention by redirecting the net contact force relative to critical joints. A method to obtain the optimal distribution of forces for a given pose via linear programming (LP) is presented. This can be applied directly to the reference gait, or combined with swaying motion. Improvements of up to 60% were observed in simulation by combining the null space with sway. The zero-interaction technique was implemented and validated on the All Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE), a hexapod robot developed by NASA for the transport of heavy cargo on the surface of the moon. Experiments with ATHLETE were conducted at the Jet Propulsion Laboratory in Pasadena, California, confirming the benefits predicted in simulation. The results of these experiments are also presented and discussed in this dissertation.

Download or read book Real time Quadruped Gait Controller for Rough Terrain Locomotion written by Wyatt Lee Ubellacker and published by . This book was released on 2016 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: In disaster situations, humanoid robots offer many advantages as first responders, but must often navigate rough and unstable terrain. The high center of mass and small support polygon of humanoids creates a difficult locomotion challenge. However, a humanoid that can transform into a quadruped for locomotion, such as MIT Biomimetic Robotics Lab's HERMES, adds the stability of a four-legged gait to safely traverse this dangerous landscape. This thesis investigates a trotting gait controller for use on HERMES specifically on rough terrain. The method takes advantage of simpler underlying dynamics of trotting stability to create a robust controller that performs without specific knowledge of the terrain or preplanning steps. Force and moment balance are conducted around the center of mass of the robot and ground reaction forces from the feet. Stance legs stabilize against disturbances in pitch, roll, and center of mass height. Swing legs attempt to land in the optimal position using a ZMP technique, and the gait cycle time is modulated to achieve stability irrespective of the foot placement constrained by the actual terrain. The controller was simulated on the HERMES humanoid robot using randomized terrain and the performance of the controller was investigated.

Download or read book Quadrupedal Locomotion written by Pablo González de Santos and published by Springer Science & Business Media. This book was released on 2007-02-17 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Walking machines have advantages over traditional vehicles, and have already accomplished tasks that wheeled or tracked robots cannot handle. Nevertheless, their use in industry and services is currently limited in scope. This book brings together methods and techniques that have been developed to deal with obstacles to wider acceptance of legged robots. Part I provides an historical overview. Part II concentrates on control techniques, as applied to Four-legged robots.

Download or read book Multi Locomotion Robotic Systems written by Toshio Fukuda and published by Springer. This book was released on 2012-06-15 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, multiple attention have been paid on a robot working in the human living environment, such as in the field of medical, welfare, entertainment and so on. Various types of researches are being conducted actively in a variety of fields such as artificial intelligence, cognitive engineering, sensor- technology, interfaces and motion control. In the future, it is expected to realize super high functional human-like robot by integrating technologies in various fields including these types of researches. The book represents new developments and advances in the field of bio-inspired robotics research introducing the state of the art, the idea of multi-locomotion robotic system to implement the diversity of animal motion. It covers theoretical and computational aspects of Passive Dynamic Autonomous Control (PDAC), robot motion control, multi legged walking and climbing as well as brachiation focusing concrete robot systems, components and applications. In addition, gorilla type robot systems are described as hardware of Multi-Locomotion Robotic system. It is useful for students and researchers in the field of robotics in general, bio-inspired robots, multi-modal locomotion, legged walking, motion control, and humanoid robots. Furthermore, it is also of interest for lecturers and engineers in practice building systems cooperating with humans.

Download or read book Bio inspired Globally Convergent Gait Regulation for a Climbing Robot written by Salomon Joseph Trujillo and published by Stanford University. This book was released on 2011 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The priorities of a climbing legged robot are to maintain a grasp on its climbing surface and to climb efficiently against the force of gravity. Climbing robots are especially susceptible to thermal overload during normal operation, due to the need to oppose gravity and to frequently apply internal forces for clinging. These priorities guided us to develop optimal climbing behaviors under thermal constraints. These behaviors in turn profoundly constrain the choice of gait regulation methods. We propose a novel algorithm: "travel-based" gait regulation that varies foot detachment timing, effectively modifying stride length and frequency in order to maintain gait phasing, subject to kinematic and stability constraints. A core feature of the algorithm is "travel, " a new metric that plays a similar role to relative phasing. The method results in linear equations in terms of travel, leading to straightforward tests for local and global convergence when, for example, disturbances such as foot slippage cause departures from the nominal phasing. We form recurrence maps and use eigenvalue and singular value decomposition to examine local convergence of gaits. To examine global convergence, we implemented a computational geometry technique in high-order spaces. Our travel-based algorithm benefits from a compact code size and ease of implementation. We implemented the algorithm on the RiSE and Stickybot III robots as well as a virtual hexapod in a physics simulator. We demonstrated quickly converging gaits on all platforms as well as gait transitions on Stickybot III and the virtual hexapod.

Download or read book Advances in Mechatronics and Biomechanics towards Efficient Robot Actuation written by Jörn Malzahn and published by Frontiers Media SA. This book was released on 2019-06-28 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gait Regulation for Bipedal Locomotion written by Jonathan Karl Holm and published by ProQuest. This book was released on 2008 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work explores regulation of forward speed, step length, and slope walking for the passive-dynamic class of bipedal robots. Previously, an energy-shaping control for regulating forward speed has appeared in the literature; here we show that control to be a special case of a more general time-scaling control that allows for speed transitions in arbitrary time. As prior work has focused on potential energy shaping for fully actuated bipeds, we study in detail the shaping of kinetic energy for bipedal robots, giving special treatment to issues of underactuation. Drawing inspiration from features of human walking, an underactuated kinetic-shaping control is presented that provides efficient regulation of walking speed while adjusting step length. Previous results on energetic symmetries of bipedal walking are also extended, resulting in a control that allows regulation of speed and step length while walking on any slope. Finally we formalize the optimal gait regulation problem and propose a dynamic programming solution seeded with passive-dynamic limit cycles. Observations of the optimal solutions generated by this method reveal further similarities between passive dynamic walking and human locomotion and give insight into the structure of minimum-effort controls for walking.

Download or read book Feedback Control of Dynamic Bipedal Robot Locomotion written by Eric R. Westervelt and published by CRC Press. This book was released on 2018-10-03 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bipedal locomotion is among the most difficult challenges in control engineering. Most books treat the subject from a quasi-static perspective, overlooking the hybrid nature of bipedal mechanics. Feedback Control of Dynamic Bipedal Robot Locomotion is the first book to present a comprehensive and mathematically sound treatment of feedback design for achieving stable, agile, and efficient locomotion in bipedal robots. In this unique and groundbreaking treatise, expert authors lead you systematically through every step of the process, including: Mathematical modeling of walking and running gaits in planar robots Analysis of periodic orbits in hybrid systems Design and analysis of feedback systems for achieving stable periodic motions Algorithms for synthesizing feedback controllers Detailed simulation examples Experimental implementations on two bipedal test beds The elegance of the authors' approach is evident in the marriage of control theory and mechanics, uniting control-based presentation and mathematical custom with a mechanics-based approach to the problem and computational rendering. Concrete examples and numerous illustrations complement and clarify the mathematical discussion. A supporting Web site offers links to videos of several experiments along with MATLAB® code for several of the models. This one-of-a-kind book builds a solid understanding of the theoretical and practical aspects of truly dynamic locomotion in planar bipedal robots.

Download or read book Control of Spring mass Running Robots written by Hamid Reza Vejdani Noghreiyan and published by . This book was released on 2013 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: We seek the control strategies that are applicable on legged robots and control them to run in real world as robust and efficient as animals. To achieve this goal, we need to understand the principles of legged locomotion and the control policies that animals use during running. In this study we tried to understand these principles by investigating birds' running experiments, and hypothesized their possible control policies that are important for real machines. We proposed two types of flight phase control techniques inspired from ground running birds for spring-mass running robots and derived mathematical formulas for the optimum design of the passive elements in these robots. For the control policies, we focused on flight phase because adjusting the leg parameters during the flight is very energy efficient and also the overall behavior of the system is very sensitive to the landing conditions that are determined during the flight phase of running. We first considered the change of the leg angle as the only control parameter during the flight phase. In the proposed control policies, three objective functions i) leg peak force, ii) axial impulse and iii) leg actuator work, all from passive stance phase, were considered to be regulated during running. It turned out that with a simple swing leg policy (constant leg angular acceleration), all the three objective functions can be nearly regulated at the same time, meaning that both goals of damage avoidance and energy efficiency can be fulfilled at once. After that, we investigated the effect of the leg length in addition to the leg angle on the dynamics of the spring-mass running robots. This control policy retains the steady state running by providing the equilibrium gait for each stride. The leg length and leg angle together make it possible for the robot to retain the steady state in the presence of a disturbance while limit the increase of the leg force which if increases may break the leg. In all of the control policies, the robot is purely passive during the stance phase and therefore the dynamics of the system comes from the passive dynamics of the system. Finally, we investigated the effect of the passive dynamics elements on the initiation of running. We derived mathematical formulas that determine the required stiffness and damping for the actuator to achieve the maximum possible performance given the physical limitations of the system.

Download or read book Intelligent Robotics and Applications written by Haibin Yu and published by Springer. This book was released on 2019-08-02 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume set LNAI 11740 until LNAI 11745 constitutes the proceedings of the 12th International Conference on Intelligent Robotics and Applications, ICIRA 2019, held in Shenyang, China, in August 2019. The total of 378 full and 25 short papers presented in these proceedings was carefully reviewed and selected from 522 submissions. The papers are organized in topical sections as follows: Part I: collective and social robots; human biomechanics and human-centered robotics; robotics for cell manipulation and characterization; field robots; compliant mechanisms; robotic grasping and manipulation with incomplete information and strong disturbance; human-centered robotics; development of high-performance joint drive for robots; modular robots and other mechatronic systems; compliant manipulation learning and control for lightweight robot. Part II: power-assisted system and control; bio-inspired wall climbing robot; underwater acoustic and optical signal processing for environmental cognition; piezoelectric actuators and micro-nano manipulations; robot vision and scene understanding; visual and motional learning in robotics; signal processing and underwater bionic robots; soft locomotion robot; teleoperation robot; autonomous control of unmanned aircraft systems. Part III: marine bio-inspired robotics and soft robotics: materials, mechanisms, modelling, and control; robot intelligence technologies and system integration; continuum mechanisms and robots; unmanned underwater vehicles; intelligent robots for environment detection or fine manipulation; parallel robotics; human-robot collaboration; swarm intelligence and multi-robot cooperation; adaptive and learning control system; wearable and assistive devices and robots for healthcare; nonlinear systems and control. Part IV: swarm intelligence unmanned system; computational intelligence inspired robot navigation and SLAM; fuzzy modelling for automation, control, and robotics; development of ultra-thin-film, flexible sensors, and tactile sensation; robotic technology for deep space exploration; wearable sensing based limb motor function rehabilitation; pattern recognition and machine learning; navigation/localization. Part V: robot legged locomotion; advanced measurement and machine vision system; man-machine interactions; fault detection, testing and diagnosis; estimation and identification; mobile robots and intelligent autonomous systems; robotic vision, recognition and reconstruction; robot mechanism and design. Part VI: robot motion analysis and planning; robot design, development and control; medical robot; robot intelligence, learning and linguistics; motion control; computer integrated manufacturing; robot cooperation; virtual and augmented reality; education in mechatronics engineering; robotic drilling and sampling technology; automotive systems; mechatronics in energy systems; human-robot interaction.

Download or read book Legged Robots that Balance written by Marc H. Raibert and published by MIT Press. This book was released on 1986 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, by a leading authority on legged locomotion, presents exciting engineering and science, along with fascinating implications for theories of human motor control. It lays fundamental groundwork in legged locomotion, one of the least developed areas of robotics, addressing the possibility of building useful legged robots that run and balance. The book describes the study of physical machines that run and balance on just one leg, including analysis, computer simulation, and laboratory experiments. Contrary to expectations, it reveals that control of such machines is not particularly difficult. It describes how the principles of locomotion discovered with one leg can be extended to systems with several legs and reports preliminary experiments with a quadruped machine that runs using these principles. Raibert's work is unique in its emphasis on dynamics and active balance, aspects of the problem that have played a minor role in most previous work. His studies focus on the central issues of balance and dynamic control, while avoiding several problems that have dominated previous research on legged machines. Marc Raibert is Associate Professor of Computer Science and Robotics at Carnegie-Mellon University and on the editorial board of The MIT Press journal, Robotics Research. Legged Robots That Balanceis fifteenth in the Artificial Intelligence Series, edited by Patrick Winston and Michael Brady.

Download or read book Bioinspired Legged Locomotion written by Maziar Ahmad Sharbafi and published by Butterworth-Heinemann. This book was released on 2017-11-21 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioinspired Legged Locomotion: Models, Concepts, Control and Applications explores the universe of legged robots, bringing in perspectives from engineering, biology, motion science, and medicine to provide a comprehensive overview of the field. With comprehensive coverage, each chapter brings outlines, and an abstract, introduction, new developments, and a summary. Beginning with bio-inspired locomotion concepts, the book's editors present a thorough review of current literature that is followed by a more detailed view of bouncing, swinging, and balancing, the three fundamental sub functions of locomotion. This part is closed with a presentation of conceptual models for locomotion. Next, the book explores bio-inspired body design, discussing the concepts of motion control, stability, efficiency, and robustness. The morphology of legged robots follows this discussion, including biped and quadruped designs. Finally, a section on high-level control and applications discusses neuromuscular models, closing the book with examples of applications and discussions of performance, efficiency, and robustness. At the end, the editors share their perspective on the future directions of each area, presenting state-of-the-art knowledge on the subject using a structured and consistent approach that will help researchers in both academia and industry formulate a better understanding of bioinspired legged robotic locomotion and quickly apply the concepts in research or products. Presents state-of-the-art control approaches with biological relevance Provides a thorough understanding of the principles of organization of biological locomotion Teaches the organization of complex systems based on low-dimensional motion concepts/control Acts as a guideline reference for future robots/assistive devices with legged architecture Includes a selective bibliography on the most relevant published articles

Download or read book Bipedal Robots written by Christine Chevallereau and published by John Wiley & Sons. This book was released on 2013-03-01 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents various techniques to carry out the gait modeling, the gait patterns synthesis, and the control of biped robots. Some general information on the human walking, a presentation of the current experimental biped robots, and the application of walking bipeds are given. The modeling is based on the decomposition on a walking step into different sub-phases depending on the way each foot stands into contact on the ground. The robot design is dealt with according to the mass repartition and the choice of the actuators. Different ways to generate walking patterns are considered, such as passive walking and gait synthesis performed using optimization technique. Control based on the robot modeling, neural network methods, or intuitive approaches are presented. The unilaterality of contact is dealt with using on-line adaptation of the desired motion.

Download or read book Proceedings written by and published by . This book was released on 1991 with total page 1170 pages. Available in PDF, EPUB and Kindle. Book excerpt: