Download or read book Trajectory Optimization for Dynamic Aerial Motions of Legged Robots written by Matthew Thomas Chignoli and published by . This book was released on 2021 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel framework for planning and executing dynamic aerial motions for legged robots is developed. These dynamic capabilities allow legged robots to conquer challenging obstacles like gaps and hurdles that cannot be traversed via standard walking and running gaits. The framework consists of two main steps. First, a motion planning step uses trajectory optimization to generate a dynamically feasible motion of the robot that achieves a desired behavior. The desired behavior, which comes from a higher-level planner or a human operator, can specify an arbitrary 3D motion task such as jumping onto a platform or performing a front flip. The trajectory optimization simultaneously optimizes the centroidal dynamics and joint-level kinematics of the robot to plan general 3D motions. Novel actuator constraints are imposed on the optimization that ensure all planned motions are feasible for implementation on hardware, and a two-stage formulation of the optimization automatically generates dynamically-informed warm starts to the optimization that dramatically reduce solve times. The second step of the framework is a unified whole-body controller that tracks these planned motions. The whole-body controller uses a prioritized task hierarchy that is optimized for robust tracking and safe landing of dynamic aerial motions. The ability of the proposed framework to reliably produce 3D aerial motions such as running jumps, barrel rolls, and flips is demonstrated on the MIT Humanoid robot in simulation and on the MIT Mini Cheetah robot both in simulation as well on hardware.

Download or read book Mixed integer Convex Optimization for Planning Aggressive Motions of Legged Robots Over Rough Terrain written by Andrés Klee Valenzuela and published by . This book was released on 2016 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planning dynamic motions for a legged robot entails addressing both the continuous question of how its joints should move and the combinatorial question of which hand or foot should touch which surface and in what order. Fortunately, these two questions are linked by the centroidal dynamics of the robot, which we can express either in terms of its joint angle trajectories or in terms of its foot placements and applied forces. Based on this insight, I formulate a pair of mathematical programs for planning highly dynamic motions for legged robots. The first is a mixed-integer convex program, specifically, a mixed-integer quadratic program (MIQP), that yields a sequence of footholds/handholds as well as center of mass (COM) and angular momentum trajectories. The second is a trajectory optimization, formulated as a nonlinear program (NLP), that returns trajectories for the COM, angular momentum, and joint angles subject to the footholds/handholds chosen by the MIQP step. While any number of trajectory optimization schemes could be used here, we present one which is particularly useful in this case, as it enforces the system's dynamics directly in terms of its COM motion and angular momentum. As a result, the solution to the MIQP provides constraints (where each end-effector is required to make contact with the environment) for the NLP and also gives seeds for the decision variables corresponding to the robot's centroidal motion. Thus, the three primary contributions of this thesis are: an MIQP-based approach to gait selection over irregular terrain, a trajectory optimization formulation for floating-base systems subject to external forces and kinematic constraints, and a planning methodology that integrates both of those to generate highly dynamic motions in challenging environments. I apply these techniques to models of a quadruped and a humanoid (Boston Dynamics' LittleDog and Atlas respectively) to generate motion plans for running, jumping, and other dynamic behaviors.

Download or read book Real time Dynamic Trajectory Optimization with Application to Free flying Space Robots written by David Wilson Miles and published by . This book was released on 1997 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Intelligent Robotics and Applications written by Huayong Yang and published by Springer Nature. This book was released on 2023-11-06 with total page 629 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 9-volume set LNAI 14267-14275 constitutes the proceedings of the 16th International Conference on Intelligent Robotics and Applications, ICIRA 2023, which took place in Hangzhou, China, during July 5–7, 2023. The 413 papers included in these proceedings were carefully reviewed and selected from 630 submissions. They were organized in topical sections as follows: Part I: Human-Centric Technologies for Seamless Human-Robot Collaboration; Multimodal Collaborative Perception and Fusion; Intelligent Robot Perception in Unknown Environments; Vision-Based Human Robot Interaction and Application. Part II: Vision-Based Human Robot Interaction and Application; Reliable AI on Machine Human Reactions; Wearable Sensors and Robots; Wearable Robots for Assistance, Augmentation and Rehabilitation of Human Movements; Perception and Manipulation of Dexterous Hand for Humanoid Robot. Part III: Perception and Manipulation of Dexterous Hand for Humanoid Robot; Medical Imaging for Biomedical Robotics; Advanced Underwater Robot Technologies; Innovative Design and Performance Evaluation of Robot Mechanisms; Evaluation of Wearable Robots for Assistance and Rehabilitation; 3D Printing Soft Robots. Part IV: 3D Printing Soft Robots; Dielectric Elastomer Actuators for Soft Robotics; Human-like Locomotion and Manipulation; Pattern Recognition and Machine Learning for Smart Robots. Part V: Pattern Recognition and Machine Learning for Smart Robots; Robotic Tactile Sensation, Perception, and Applications; Advanced Sensing and Control Technology for Human-Robot Interaction; Knowledge-Based Robot Decision-Making and Manipulation; Design and Control of Legged Robots. Part VI: Design and Control of Legged Robots; Robots in Tunnelling and Underground Space; Robotic Machining of Complex Components; Clinically Oriented Design in Robotic Surgery and Rehabilitation; Visual and Visual-Tactile Perception for Robotics. Part VII: Visual and Visual-Tactile Perception for Robotics; Perception, Interaction, and Control of Wearable Robots; Marine Robotics and Applications; Multi-Robot Systems for Real World Applications; Physical and Neurological Human-Robot Interaction. Part VIII: Physical and Neurological Human-Robot Interaction; Advanced Motion Control Technologies for Mobile Robots; Intelligent Inspection Robotics; Robotics in Sustainable Manufacturing for Carbon Neutrality; Innovative Design and Performance Evaluation of Robot Mechanisms. Part IX: Innovative Design and Performance Evaluation of Robot Mechanisms; Cutting-Edge Research in Robotics.

Download or read book Demonstration Based Trajectory Optimization for Generalizable Robot Motions written by Dorothea Koert and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Whole body Trajectory Generation and Control Strategies for Multi contact Robots written by Jaemin Lee (Ph. D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental objective of robotics is to enhance the productivity of humans while interacting in potentially unstructured environments. In this sense, Human-centered robots must be fast, stable, and robust when performing varied and complicated tasks during mission execution. Although industrial robots have seen some advancements regarding motion planning and control, they are largely limited to simple pre-defined tasks in structured environments. However, to achieve highly dynamic motions for dexterous manipulation or agile locomotion in complex robots, we need to consider the use of nonlinear dynamics, complex constraints, multiple contacts, disturbances, and uncertainties. These are fundamental requirements needed to advance the use of general purpose robots dynamically interacting in a wider variety of environments. Therefore, this thesis addresses challenges that arise from the employment of optimization techniques and sophisticated realtime algorithms for the control and deployment of realistic and practical robots in human environments. Considering the above challenges, we propose efficient trajectory generation and trajectory tracking methods as the next paradigms for whole-body control (WBC). First, we formulate a class of motion planning problems to directly obtain dynamically feasible state trajectories in multi-contact robots and the corresponding control inputs. Typically, it takes a tremendous amount of time to solve the end-to-end trajectory generation problem using large-scale standard Nonlinear Programming (NLP). We propose a new sampling-based method together with a Partially Observable Markov Decision Process to break down the trajectory generation problem into tractable parts. In doing so, the number of decision variables is drastically reduced. As a result, we solve the optimization problem much faster than using existing NLP techniques. In addition, we incorporate reachability analysis tools for determining whether the planned trajectories are reachable and discard unfeasible trajectories during optimization. Because simplified models are frequently utilized in locomotion studies to generate walking patterns, planned contact locations may not be feasible due to model mismatch and robot constraints. In contrast, our method enables the generation of dynamically feasible trajectories to reach planned contact location considering full-body dynamics and realistic constraints. The proposed methods are applied to contact constrained manipulation and bipedal locomotion problems to enhance capabilities of robots maneuvering in complex environments without slip or loss of balance. Second, we explore the fundamentals of WBC and use this insight to push forward the capabilities of WBC approaches. One of the problems we explore is the verification of stability of legged robots under unknown external perturbations. In such cases, the closed-loop control system controlled by WBC approaches may become unstable if external perturbations are not properly analyzed with stability verification. To verify stability, we leverage the so-called Centroidal Dynamics of legged robots and a type of WBC dubbed Whole-Body Locomotion Control (WBLC). Using a feedback-linearized state-space model, we obtain appropriate feedback gains for WBC to make our robot stable and robust under perturbations. Another challenge of WBC stems from the reliance on classical feedback control theory. Classical PD control is unsuitable for a noisy system, therefore WBC cannot be directly applied to stochastic systems. Classical WBC approaches do not consider the covariance of the terminal states as constraints which is a more efficient way to control robots with precision. We propose a new control approach, called Hierarchical Covariance Control (HCC) to enforce covariance constraints. Our proposed HCC is a stochastic version of WBC to decrease task errors when uncertainty is substantial. The last improvement I explore regarding WBC is the employment of Model Predictive Control (MPC) instead of solving an instantaneous optimization problem, which cannot guarantee global optimality. As such, we consider longer receding time horizons for MPC, thus improving the tracking performance by reducing the accumulated error norm while executing hierarchical tasks. Overall, our research focuses on the end-to-end process spanning trajectory planning to feedback control enabling the generating of multi-contact and constrained dynamic motions of complex robots operating in realistic setups. The various contributions of this thesis are in the areas of computational efficiency for whole-body trajectory generation, robustness of WBC control algorithms, and significant improvements in trajectory tracking using WBC algorithms. We verify the proposed approaches both in simulations and real experiments using various robotic systems

Download or read book Visual Guidance of Unmanned Aerial Manipulators written by Angel Santamaria-Navarro and published by Springer. This book was released on 2018-08-18 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph covers theoretical and practical aspects of the problem of autonomous guiding of unmanned aerial manipulators using visual information. For the estimation of the vehicle state (position, orientation, velocity, and acceleration), the authors propose a method that relies exclusively on the use of low-cost and highrate sensors together with low-complexity algorithms. This is particularly interesting for applications in which on board computation with low computation power is needed. Another relevant topic covered in this monograph is visual servoing. The authors present an uncalibrated visual servo scheme, capable of estimating at run time, the camera focal length from the observation of a tracked target. The monograph also covers several control techniques, which achieve a number of tasks, such as robot and arm positioning, improve stability and enhance robot arm motions. All methods discussed in this monograph are demonstrated in simulation and through real robot experimentation. The text is appropriate for readers interested in state estimation and control of aerial manipulators, and is a reference book for people who work in mobile robotics research in general.

Download or read book Theory and Applications for Control of Aerial Robots in Physical Interaction Through Tethers written by Marco Tognon and published by Springer Nature. This book was released on 2020-06-26 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies how autonomous aerial robots physically interact with the surrounding environment. Intended to promote the advancement of aerial physical interaction, it analyzes a particular class of aerial robots: tethered aerial vehicles. By examining specific systems, while still considering the challenges of the general problem, it will help readers acquire the knowledge and expertise needed for the subsequent development of more general methods applicable to aerial physical interaction. The formal analysis covers topics ranging from control, state estimation, and motion planning, to experimental validation. Addressing both theoretical and technical aspects, the book is intended for a broad academic and industrial readership, including undergraduate students, researchers and engineers. It can be used as a teaching reference, or as the basis for product development.

Download or read book Adaptive Dynamic Walking and Motion Optimization for Humanoid Robots written by Andreas Seekircher and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential ability of a robot is to act in its environment by generating motions for locomotion or manipulation. This can be a challenging problem on a robot with high degrees of freedom. Although biped robots have shown drastic improvements with regard to motion skills over the past few years, many approaches for generating motions still require tedious and time-consuming manual calibration due to variances in the hardware or inaccurate sensors and actuators. This research focuses on generating motions for humanoid robots automatically without manual calibration. The first approach discussed uses parameter optimization (e.g. CMA-ES, PSO) to directly optimize the joint angle trajectories for various motions. Using optimization we produce motions for NAO robots in the RoboCup 3D Soccer Simulation League that are far superior to hand tuned motions or stabilize motions generated from noisy motion capture data from a Microsoft Kinect. The second part describes a dynamically generated closed-loop gait for simulated and physical NAOs using a linear inverted pendulum model (LIPM), which keeps the zero moment point (ZMP) within given constraints. This is a common approach, but due to variances in the hardware and environment it still requires manual fine-tuning. Our experiments show that the model errors can be reduced by optimizing parameters of the model using the observed behavior while walking. Improving the model produces better predictions of the robots behavior which yields a more stable walk without requiring manual calibration.

Download or read book Dynamic Robot Motions and Dynamic Load Carrying Capacity Computation written by Li-Chun Tommy Wang and published by . This book was released on 1986 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hybrid Dynamic Simulation for Performance Optimization of Legged Mechanisms written by Daniel Montrallo Flickinger and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Agile locomotion is needed for mobile robots to efficiently navigate challenging terrain. The ability of an agile legged mobile robot to abruptly change trajectory allows it to quickly react to obstacles and successfully operate in environments usually more suited for legged animals. The research presented herein aims to increase the agility and performance of legged robots. Using hybrid dynamic simulation, novel methods are developed to model the interaction of a legged robot with the ground. In considering robot agility, an accurate model of the events that occur while in contact is needed. Methods are developed to model ground interaction where oblique angled impacts occur, and to address the well known issues with energy consistency when using rigid body models for dynamic systems. The contact model in this work is investigated with three multibody benchmark cases. A cable driven single leg jumping robot is modeled to research agility. An optimization of the initial posture of the robot, and its effect on jumping performance and agility is presented. Configuration optimization during the stance phase of a non-periodic jumping motion is performed, utilizing the directional dynamic capability equations. This optimization maximizes the time the mechanism is in contact with the ground, minimizes actuation effort, and reduces the likelihood of slipping and stumbling.

Download or read book Optimization based Motion Planning for Legged Robots written by Alexander W. Winkler and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Robust Trajectory Optimization and Control of a Dynamic Soaring Unmanned Aerial Vehicle written by Tristan Charles Flanzer and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A robust trajectory optimization method is formulated using a stochastic collocation based approach and is then applied to the design of periodic dynamic soaring trajectories for unmanned aerial vehicles (UAVs). Repetitive control is proposed and evaluated as a means for reducing tracking error for UAVs flying periodic trajectories both in simulation and experimentally. Experiments conducted in an indoor flying laboratory outfitted with a VICON motion capture system demonstrate significant reductions in tracking error even in the presence of large and unknown disturbances.

Download or read book Optimization based Multi contact Motion Planning for Legged Robots written by Iordanis Chatzinikolaidis and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Motion Optimization and Control of Single and Multiple Autonomous Aerial Land and Marine Robots written by Reza Ghabcheloo and published by Mdpi AG. This book was released on 2023-01-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reprint focuses on a number of timely and challenging issues in areas that support the design, implementation, and experimental testing of single and multiple autonomous air, land, and marine robots. Special emphasis is placed on the methods and techniques employed for motion planning and control that are rooted in solid theoretical concepts. Applications are also addressed in the area of advanced manipulator control. The reprint affords the reader a well-balanced presentation of a wide spectrum of topics that include, but are not limited to, the generation of optimal collision-free trajectories for heterogeneous vehicles working collaboratively or independently, the rapid adaptation of manipulator trajectories to task perturbations, the automatic collision avoidance for surface vessels, the path following controllers for marine and ground robots, the large-scale swarm counterattack strategies, and the optimal actuator configuration design for over-actuated underwater robots.

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 2012-10-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A much-needed, state-of-the-art guide on building complex legged robots Robot control of dynamical legged locomotion has seen tremendous advances in recent decades, with hundreds of walking mechanisms being built in laboratories worldwide, helping people with disabilities and serving as replacements for humans operating in hazardous environments. 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 the engineering detail readers' need to achieve dynamical legged locomotion, 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. Researchers and practicing engineers familiar with robotics and control systems will gain a thorough understanding of: Hybrid systems and systems with impulse effects Offline and online motion planning algorithms to generate periodic walking and running motions Two-level control schemes, including within-stride feedback laws to reduce the dimension of the hybrid systems Continuous-time update laws to minimize a general cost function online Event-based update laws to asymptotically stabilize periodic orbits Complete with downloadable MATLAB code of the control algorithms and schemes used in the book, Hybrid Control and Motion Planning of Dynamical Legged Locomotion is an invaluable guide to the latest developments and future trends in dynamical legged locomotion.