Download or read book Visual Control of Legged Robots for Locomotion in Complex Environments Using Central Pattern Generators written by Sébastien Gay and published by . This book was released on 2014 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hybrid Control and Motion Planning of Dynamical Legged Locomotion written by Nasser Sadati and published by John Wiley & Sons. This book was released on 2012-09-11 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the need in the field for a comprehensive review of motion planning algorithms and hybrid control methodologies for complex legged robots. Introducing a multidisciplinary systems engineering approach for tackling many challenges posed by legged locomotion, the book provides engineering detail including hybrid models for planar and 3D legged robots, as well as hybrid control schemes for asymptotically stabilizing periodic orbits in these closed-loop systems. Complete with downloadable MATLAB code of the control algorithms and schemes used in the book, this book is an invaluable guide to the latest developments and future trends in dynamical legged locomotion.

Download or read book Actuation Aware Simplified Dynamic Models for Robotic Legged Locomotion written by Romeo Orsolino and published by Istitituto Italiano di Tecnologia (IIT). This book was released on 2019-02-14 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recent years, we witnessed an ever increasing number of successful hardware implementations of motion planners for legged robots. If one common property is to be identified among these real-world applications, that is the ability of performing online (re)planning. Online planning is forgiving, in the sense that it allows to relentlessly compensate for external disturbances of whatever form they might be, ranging from unmodeled dynamics to external pushes or unexpected obstacles and, at the same time, follow user commands. Initially replanning was restricted only to heuristic-based planners that exploit the low computational effort of simplified dynamic models. Such models deliberately only capture the main dynamics of the system, thus leaving to the controllers the issue of anchoring the desired trajectory to the whole body model of the robot. In recent years, however, a number of novel Model Predictive Control (MPC) approaches have been presented that attempt to increase the accuracy of the obtained solutions by employing more complex dynamic formulations, this without trading-off the computational efficiency of simplified models. In this dissertation, as an example of successful hardware implementation of heuristics and simplified model-based locomotion, I first describe the control framework that I developed for the generation of an omni-directional bounding gait for the HyQ quadruped robot. By analyzing the stable limit cycles for the sagittal dynamics and the Center of Pressure (CoP) for the lateral stabilization, the described locomotion framework is able to achieve a stable bounding gait while adapting the footsteps to terrains of mild roughness and to sudden changes of the user desired linear and angular velocities. The next topic reported and second contribution of this dissertation is my effort to formulate more descriptive simplified dynamic models, without compromising their computational efficiency, in order to extend the navigation capabilities of legged robots to complex geometry environments. With this in mind, I investigated the possibility of incorporating feasibility constraints in these template models and, in particular, I focused on the joint-torque limits, which are usually neglected at the planning stage. Along the same direction, the third contribution discussed in this thesis is the formulation of the so called actuation wrench polytope (AWP), defined as the set of feasible wrenches that an articulated robot can perform given its actuation limits. Interesected with the contact wrench cone (CWC), this yields a new 6D polytope that we name feasible wrench polytope (FWP), defined as the set of all wrenches that a legged robot can realize given its actuation capabilities and the friction constraints. Results are reported where, thanks to efficient computational geometry algorithms and to appropriate approximations, the FWP is employed for a one-step receding horizon optimization of center of mass trajectory and phase durations given a predefined step sequence on rough terrains. In order to augment the robot’s reachable workspace, I then decided to trade off the generality of the FWP formulation for a suboptimal scenario in which a quasi-static motion is assumed. This led to the definition of a new concept that I refer to under the name of feasible region. This can be seen as a different variant of 2D linear subspaces orthogonal to gravity where the robot is guaranteed to place its own center of mass (CoM) while being able to carry its own body weight given its actuation capabilities. The feasible region provides an intuitive tool for the visualization in 2D of the actuation capabilities of legged robots. The low dimensionality of the feasible region also enables the concurrent online optimization of actuation consistent CoM trajectories and target foothold locations on rough terrains, which can hardly be achieved with other state-of-the-art approaches.

Download or read book Humanoid Robotics A Reference written by Prahlad Vadakkepat and published by Springer. This book was released on 2017-02-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humanoid Robotics provides a comprehensive compilation of developments in the conceptualization, design and development of humanoid robots and related technologies. Human beings have built the environment they occupy (living spaces, instruments and vehicles) to suit two-legged systems. Building systems, especially in robotics, that are compatible with the well-established, human-based surroundings and which could naturally interact with humans is an ultimate goal for all researches and engineers. Humanoid Robots are systems (i.e. robots) which mimic human behavior. Humanoids provide a platform to study the construction of systems that behave and interact like humans. A broad range of applications ranging from daily housework to complex medical surgery, deep ocean exploration, and other potentially dangerous tasks are possible using humanoids. In addition, the study of humanoid robotics provides a platform to understand the mechanisms and offers a physical visual of how humans interact, think, and react with the surroundings and how such behaviors could be reassembled and reconstructed. Currently, the most challenging issue with bipedal humanoids is to make them balance on two legs, The purportedly simple act of finding the best balance that enables easy walking, jumping and running requires some of the most sophisticated development of robotic systems- those that will ultimately mimic fully the diversity and dexterity of human beings. Other typical human-like interactions such as complex thought and conversations on the other hand, also pose barriers for the development of humanoids because we are yet to understand fully the way in which we humans interact with our environment and consequently to replicate this in humanoids.

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 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 Biped Locomotion written by Miomir Vukobratovic and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here for the first time in one book is a comprehensive and systematic approach to the dynamic modeling and control of biped locomotion robots. A survey is included of various approaches to the control of biped robots, and a new approach to the control of biped systems based on a complete dynamic model is presented in detail. The stability of complete biped system is presented for the first time as a highly nonlinear dynamic system. Also included is new software for the synthesis of a dynamically stable walk for arbitrary biped systems, presented here for the first time. A survey of various realizations of biped systems and numerous numerical examples are given. The reader is given a deep insight into the entire area of biped locomotion. The book covers all relevant approaches to the subject and gives the most complete account to date of dynamic modeling, control and realizations of biped systems.

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 Control Implementation of Dynamic Locomotion on Compliant Underactuated Force Controlled Legged Robots with Non Anthropomorphic Design written by Jeffrey Chen Yu and published by . This book was released on 2020 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: The control of locomotion on legged robots traditionally involves a robot that takes a standard legged form, such as the anthropomorphic humanoid, the dog-like quadruped, or the bird-like biped. Additionally, these systems will often be actuated with position-controlled servos or series-elastic actuators that are connected through rigid links. This work investigates the control implementation of dynamic, force-controlled locomotion on a family of legged systems that significantly deviate from these classic paradigms by incorporating modern, state-of-the-art proprioceptive actuators on uniquely configured compliant legs that do not closely resemble those found in nature. The results of this work can be used to better inform how to implement controllers on legged systems without stiff, position-controlled actuators, and also provide insight on how intelligently designed mechanical features can potentially simplify the control of complex, nonlinear dynamical systems like legged robots. To this end, this work presents the approach to control for a family of non-anthropomorphic bipedal robotic systems which are developed both in simulation and with physical hardware. The first is the Non-Anthropomorphic Biped, Version 1 (NABi-1) that features position-controlled joints along with a compliant foot element on a minimally actuated leg, and is controlled using simple open-loop trajectories based on the Zero Moment Point. The second system is the second version of the non-anthropomorphic biped (NABi-2) which utilizes the proprioceptive Back-drivable Electromagnetic Actuator for Robotics (BEAR) modules for actuation and fully realizes feedback-based force controlled locomotion. These systems are used to highlight both the strengths and weaknesses of utilizing proprioceptive actuation in systems, and suggest the tradeoffs that are made when using force control for dynamic locomotion. These systems also present case studies for different approaches to system design when it comes to bipedal legged robots.

Download or read book A General Model of Legged Locomotion on Natural Terrain written by David J. Manko and published by Springer. This book was released on 2012-11-10 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic modeling is the fundamental building block for mechanism analysis, design, control and performance evaluation. One class of mechanism, legged machines, have multiple closed-chains established through intermittent ground contacts. Further, walking on natural terrain introduces nonlinear system compliance in the forms of foot sinkage and slippage. Closed-chains constrain the possible motions of a mechanism while compliances affect the redistribution of forces throughout the system. A General Model of Legged Locomotion on Natural Terrain develops a dynamic mechanism model that characterizes indeterminate interactions of a closed-chain robot with its environment. The approach is applicable to any closed-chain mechanism with sufficient contact compliance, although legged locomotion on natural terrain is chosen to illustrate the methodology. The modeling and solution procedures are general to all walking machine configurations, including bipeds, quadrupeds, beam-walkers and hopping machines. This work develops a functional model of legged locomotion that incorporates, for the first time, non-conservative foot-soil interactions in a nonlinear dynamic formulation. The model was applied to a prototype walking machine, and simulations generated significant insights into walking machine performance on natural terrain. The simulations are original and essential contributions to the design, evaluation and control of these complex robot systems. While posed in the context of walking machines, the approach has wider applicability to rolling locomotors, cooperating manipulators, multi-fingered hands, and prehensile agents.

Download or read book Fast Sensing and Adaptive Actuation for Robust Legged Locomotion written by An Mo and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Robust legged locomotion in complex terrain demands fast perturbation detection and reaction. In animals, due to the neural transmission delays, the high-level control loop involving the brain is absent from mitigating the initial disturbance. Instead, the low-level compliant behavior embedded in mechanics and the mid-level controllers in the spinal cord are believed to provide quick response during fast locomotion. Still, it remains unclear how these low- and mid-level components facilitate robust locomotion. This thesis aims to identify and characterize the underlining elements responsible for fast sensing and actuation. To test individual elements and their interplay, several robotic systems were implemented. The implementations include active and passive mechanisms as a combination of elasticities and dampers in multi-segment robot legs, central pattern generators inspired by intraspinal controllers, and a synthetic robotic version of an intraspinal sensor. The first contribution establishes the notion of effective damping. Effective damping is defined as the total energy dissipation during one step, which allows quantifying how much ground perturbation is mitigated. Using this framework, the optimal damper is identified as viscous and tunable. This study paves the way for integrating effective dampers to legged designs for robust locomotion. The second contribution introduces a novel series elastic actuation system. The proposed system tackles the issue of power transmission over multiple joints, while featuring intrinsic series elasticity. The design is tested on a hopper with two more elastic elements, demonstrating energy recuperation and enhanced dynamic performance. The third contribution proposes a novel tunable damper and reveals its influence on legged hopping. A bio-inspired slack tendon mechanism is implemented in parallel with a spring. The tunable damping is rigorously quantified on a central-pattern-generator-driven hopping robot, which reveals the trade-off between locomotion robustness and efficiency. The last contribution explores the intraspinal sensing hypothesis of birds. We speculate that the observed intraspinal structure functions as an accelerometer. This accelerometer could provide fast state feedback directly to the adjacent central pattern generator circuits, contributing to birds' running robustness. A biophysical simulation framework is established, which provides new perspectives on the sensing mechanics of the system, including the influence of morphologies and material properties. Giving an overview of the hierarchical control architecture, this thesis investigates the fast sensing and actuation mechanisms in several control layers, including the low-level mechanical response and the mid-level intraspinal controllers. The contributions of this work provide new insight into animal loco-motion robustness and lays the foundation for future legged robot design.

Download or read book Tri Modal Models of Locomotion Applications to Robot Design and Control written by Max Austin and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Everyday animals maneuver through complex unstructured environments provided by the natural world. One way in which we can study these behaviors in animals is by partitioning the natural world into differing domains and analyzing the modes of locomotion employed by animals within them. Though animals appear to achieve multi-modality with apparent ease no robots have yet been able to approach the same degree of modal diversity. Some motivating reasons for this derive from limited understandings of the intersection between domains and how uniting these diverse modes changes the design of mechanisms and control. This work seeks to develop tools to assist with the task of bridging three different domains of legged locomotion. In particular, this work takes its primary focus on developing models which intersect with the aquatic domain, which has been largely unmodeled for legged robotics. To that end, the first thrust of this work entails developing a model that intersects between the scansorial and aquatic domains of legged locomotion. This model is then evaluated by the first legged robot capable of producing both of these forms of locomotion. Following this the a new model is developed to capture the intersection between the aquatic and terrestrial domains, which also serves to evaluate different levels of hydrodynamic complexity. It is shown here that optimizing a simple version of this model the efficiency of hopping in resistive media can be greatly improved and that differing levels of model can show a good degree of accuracy with legged swimming. Finally, some of the models of locomotion are applied to the task of robotic design for dynamically challenging behaviors including: enabling high performance terrestrial gaits on the large robot LLAMA, and enabling multi-modality on a newly designed small scale robot.

Download or read book Humanoid Robots written by Armando Carlos De Pina Filho and published by IntechOpen. This book was released on 2007-06-01 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many years, the human being has been trying, in all ways, to recreate the complex mechanisms that form the human body. Such task is extremely complicated and the results are not totally satisfactory. However, with increasing technological advances based on theoretical and experimental researches, man gets, in a way, to copy or to imitate some systems of the human body. These researches not only intended to create humanoid robots, great part of them constituting autonomous systems, but also, in some way, to offer a higher knowledge of the systems that form the human body, objectifying possible applications in the technology of rehabilitation of human beings, gathering in a whole studies related not only to Robotics, but also to Biomechanics, Biomimmetics, Cybernetics, among other areas. This book presents a series of researches inspired by this ideal, carried through by various researchers worldwide, looking for to analyze and to discuss diverse subjects related to humanoid robots. The presented contributions explore aspects about robotic hands, learning, language, vision and locomotion.

Download or read book An Overview on Balancing and Stabilization Control of Biped Robots written by Hayder Al-Shuka and published by GRIN Verlag. This book was released on 2017-10-17 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Academic Paper from the year 2017 in the subject Engineering - Robotics, , language: English, abstract: Researchers dream of developing autonomous humanoid robots which behave/walk like a human being. Biped robots, although complex, have the greatest potential for use in human-centered environments such as the home or office. Studying biped robots is also important for understanding human locomotion and improving control strategies for prosthetic and orthotic limbs. Control systems of humans walking in cluttered environments are complex, however, and may involve multiple local controllers and commands from the cerebellum. Although biped robots have been of interest over the last four decades, no unified stability/balance criterion adopted for stabilization of miscellaneous walking/running modes of biped robots has so far been available. The literature is scattered and it is difficult to construct a unified background for the balance strategies of biped motion. The zero-moment point (ZMP) criterion, however, is a conservative indicator of stabilized motion for a class of biped robots. Therefore, we offer a systematic presentation of multi-level balance controllers for stabilization and balance recovery of ZMP-based humanoid robots.

Download or read book Walking Machines written by D. J. Todd and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first chapter of this book traces the history of the development of walking machines from the original ideas of man-amplifiers and military rough-ground transport to today's diverse academic and industrial research and development projects. It concludes with a brief account of research on other unusual methods of locomotion. The heart of the book is the next three chapters on the theory and engineering of legged robots. Chapter 2 presents the basics of land loco motion, going on to consider the energetics of legged movement and the description and classification of gaits. Chapter 3, dealing with the mechanics of legged vehicles, goes into leg number and arrangement, and discusses mechanical design and actuation methods. Chapter 4 deals with analysis and control, describing the aims of control theory and the methods of modelling and control which have been used for both highly dynamic robots and multi-legged machines. Having dealt with the theory of control it is necessary to discuss the computing system on which control is to be implemented. This is done in Chapter 5, which covers architectures, sensing, algorithms and pro gramming languages. Chapter 6 brings together the threads of the theory and engineering discussed in earlier chapters and summarizes the current walking machine research projects. Finally, the applications, both actual and potential, of legged locomotion are described. Introduction Research into legged machines is expanding rapidly. There are several reasons why this is happening at this particular time.

Download or read book Autonomous Generation and Control of Central Pattern Generator Networks for Modular Robot Locomotion written by Kevin J. Gucwa and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modular robots hold the promise of being a complete solution to many problems within science. Their adaptability within hardware and software can provide the right robot for each and every situation. Properly controlling the hardware with coordinated locomotion is challenging but essential for the modules to work together and perform the assigned tasks. This research study has developed a two tiered approach which can coordinate and control the locomotion of modular robots assembled into bio-inspired shapes. The lowest level of control is in the joint space whereby all joints need to perform the right actions at the right time to produce a collaborative effort that results in locomotion. To accomplish this the Central Pattern Generator (CPG) network concept is applied from spinal vertebrate locomotion control. Each joint within the robot contributes in a small way to produce a coordinated, collaborative motion utilizing the whole body in unison. On top of the CPG network is a controller derived from the brain's cerebellum control system to modulate the CPG network to perform specific tasks such as path following. To accomplish the CPG-based coordinate locomotion, a tool kit for automatically generating the Central Pattern Generator equations is presented. Robot shapes created in XML are read and parsed to determine sub-structures of the robot which adhere to common and known locomotion patterns for the specific modular robot currently utilized. Locomotion is based upon coordinated whole-body motion which is necessary for low-powered modular robots, such as the Linkbot used in this research, to create locomotion. By parsing the structure, the number of optimizable control parameters is drastically reduced to aid inefficient simulation of motion parameters. A simulation-based Genetic Algorithm process is used to generate motions and optimize the parameters of motion. The reduction in control parameters for large structures is an order of magnitude from the theoretical maximum. From simulated results of various shapes constructed out of the modules, the parsing of the shape increases the robot's linear speed when compared to optimizing all variables of the CPG network. The CPG networks capabilities are validated with hardware versions of the robots. Once the CPG network has been determined which effectively controls a particular shape of robot, the network can be modulated to produce specific locomotion capabilities. Coordination between the joints is created by the network to produce locomotion. The control scheme on top of the CPG network is necessary to create a robot that can move predictably and follow objective trajectories. Again the control system takes inspiration from biology to provide real-time control of the CPG network that is controlling the modular robot configurations. In this research the brain's cerebellum, which is in charge of modulating the walking characteristics of humans, is modeled to modulate the CPG network tocreate path-following robots. Waypoints are used to generate cubic spline paths for the robot; a camera is used to track the robot's heading in reference to the path; and the error in heading is passed into a fuzzy controller to convert the heading error into a turn signal that is applied to the robot's CPG network. The CPG network and controller are calculated online in real-time to follow the desired trajectories. Experiments have been completed within a simulation environment built specifically for the robots used. The robots are able to accurately track the various paths laid out irregardless of the complexity and length. Root Mean Square (RMS) error is calculated for each of the experiments and shows that the robots can maintain an error between five and twelve centimeters for paths that average eight meters in length. For the snake robot the robustness of the controller is checked by adjusting the friction between the robot and the ground. This controller is not affected by changes in friction which alter the motion characteristics of the CPG network.

Download or read book Spiking Central Pattern Generators Through Reverse Engineering of Locomotion Patterns written by Andrés Espinal and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In robotics, there have been proposed methods for locomotion of nonwheeled robots based on artificial neural networks; those built with plausible neurons are called spiking central pattern generators (SCPGs). In this chapter, we present a generalization of reported deterministic and stochastic reverse engineering methods for automatically designing SCPG for legged robots locomotion systems; such methods create a spiking neural network capable of endogenously and periodically replicating one or several rhythmic signal sets, when a spiking neuron model and one or more locomotion gaits are given as inputs. Designed SCPGs have been implemented in different robotic controllers for a variety of robotic platforms. Finally, some aspects to improve and/or complement these SCPG-based locomotion systems are pointed out.