Download or read book A Variable Stiffness Robotic Arm Design Using Linear Actuated Compliant Parallel Guided Mechanism written by Ruiqi Hu (Mechanical engineer) and published by . This book was released on 2017 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the development details of a human safety robotic arm design with variable stiffness, starting from an initial conceptual design to prototype validations. Instead of changing the compliance of the joint, this design concept introduces compliance to the robotic link itself. The mechanism of the design is a parallel guided beam with a slider linear actuated by a power screw and a DC motor. By controlling the slider position, the effective length of the robotic arm link can be adjusted to achieve necessary stiffness change. The stiffness variation capability of the effective length concept was first validated on a physical conceptual model by experiments. For comparison, a simulation model was also created for the structure of the robotic arm in Abaqus using finite element methods. All the analysis, simulation and tests performed in this research were based on small beam bending deflections. A prototype was developed based on the conceptual model, having transmission and actuation module integrated. Simple and accurate PID position control using Arduino for rapid prototyping is also demonstrated in this thesis. The performance of the prototype was evaluated by two categories of experiments: stiffness tests and PID position calibration. The overall stiffness change ratio achieved was around 20 times by static stiffness test results. The position steady state error and the overshoot of the system was within 0.5mm.

Download or read book Mechanism Design for Robotics written by Marco Ceccarelli and published by MDPI. This book was released on 2019-06-21 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: MEDER 2018, the IFToMM International Symposium on Mechanism Design for Robotics, was the fourth event in a series that was started in 2010 as a specific conference activity on mechanisms for robots. The aim of the MEDER Symposium is to bring researchers, industry professionals, and students together from a broad range of disciplines dealing with mechanisms for robots, in an intimate, collegial, and stimulating environment. In the 2018 MEDER event, we received significant attention regarding this initiative, as can be seen by the fact that the Proceedings contain contributions by authors from all around the world. The Proceedings of the MEDER 2018 Symposium have been published within the Springer book series on MMS, and the book contains 52 papers that have been selected after review for oral presentation. These papers cover several aspects of the wide field of robotics dealing with mechanism aspects in theory, design, numerical evaluations, and applications. This Special Issue of Robotics (https://www.mdpi.com/journal/robotics/special_issues/MDR) has been obtained as a result of a second review process and selection, but all the papers that have been accepted for MEDER 2018 are of very good quality with interesting contents that are suitable for journal publication, and the selection process has been difficult.

Download or read book A Compliant Mechanism based Variable stiffness Joint written by Jacob M. Robinson and published by . This book was released on 2015 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of current variable-stiffness actuators reveals a need for more simple, cost effective, and lightweight designs that can be easily incorporated into a variety of human-interactive robot platforms. This thesis considers the potential use of compliant mechanisms to improve the performance of variable-stiffness actuators. The advantages and disadvantages of various concepts using compliant mechanisms are outlined, along with ideas for further exploration. A new variable-stiffness actuator that uses a compliant flexure as the elastic element has been modeled, built, and tested. This new design involves a variable stiffness joint that makes use of a novel variable transmission. A prototype has been built and tested to verify agreement with the model which shows a reasonable range of stiffness and good repeatability. Ideas for further exploration are identified.

Download or read book Finite and Instantaneous Screw Theory in Robotic Mechanism written by Tao Sun and published by Springer Nature. This book was released on 2020-02-13 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a finite and instantaneous screw theory for the development of robotic mechanisms. It addresses the analytical description and algebraic computation of finite motion, resulting in a generalized type synthesis approach. It then discusses the direct connection between topology and performance models, leading to an integrated performance analysis and design framework. The book then explores parameter uncertainty and multiple performance requirements for reliable, optimal design methods, and describes the error accumulation principle and parameter identification algorithm, to increase robot accuracy. It proposes a unified and generic methodology, and appliesto the invention, analysis, design, and calibration of robotic mechanisms. The book is intended for researchers, graduate students and engineers in the fields of robotic mechanism and robot design and applications./div

Download or read book Design and Modeling of Variable Stiffness Mechanisms Based on Layer Jamming for Robotic Applications written by Xianpai Zeng and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research is on the design of variable stiffness robotic gripper, that is, how variable stiffness gripper might be designed to for it to grasp light objects with low stiffness for the delicacy and grasp heavy objects with high stiffness for the strength. I break my work into three topics: (1) exploring how layer jamming works, (2) enhancing the performance of layer jamming mechanism by identifying all the sensitive design parameters, and (3) creating grippers equipped with layer jamming. The first of these aims to answer scientific questions, such as what are the fundamental mechanics that make layer jamming work. The second of these is to identify which design parameters contribute most to the stiffness change. And the third concerns the application of the optimized design guidelines.

Download or read book Cable Driven Parallel Robots written by Tobias Bruckmann and published by Springer Science & Business Media. This book was released on 2012-09-09 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gathering presentations to the First International Conference on Cable-Driven Parallel Robots, this book covers classification and definition, kinematics, workspace analysis, cable modeling, hardware/prototype development, control and calibration and more.

Download or read book Design of a Variable Stiffness Passive Layer Jamming Structure for Anthropomorphic Robotic Finger Applications written by Nkemdilim Okechukwu Umezude and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soft robots can effectively mimic human hand interface characteristics and facilitate collaborative operations with humans in a safe manner. This dissertation research concerns the design and fabrication of a low cost variable stiffness structure for applications in compliant robotic fingers. A conceptual design of a compact multi-layer structure is proposed for realizing variable stiffness, when applied to underactuated fingers of an anthropomorphic robotic hand. The proposed design comprises thin material layers with clearance that permits a progressive hardening feature while grasping and added design flexibility and tuning of the fingers' compliance. The design permits stiffness variations in a passive manner in the soft contact regions. The design is realized to ensure ease of scalability and cost-effective fabrication by the 'Additive Manufacturing (AM)'/3D-printing technology. Both the multi-layer structures and the fingers could be fabricated as a single entity, and from a single base material with relatively low elastic modulus. The proposed design also exhibits finite degrees-of-freedom representative of the human finger - The feasibility of the design and its manufacturability are verified through prototype fabrication using a readily available 3D-printing material, namely; 'Thermoplastic PolyUrethane (TPU)' with Young's Modulus of 25MPa. The chosen material permitted low stiffness of the multi-layer structure in the contact interface under relatively small deformations, while ensuring sufficient rigidity on the non-contact regions of the finger. A finite element (FE) model is formulated considering 3D tetrahedral elements and a nodal-normal contact detection method together with the augmented Lagrange formulation. The model is analyzed to determine the force-displacement characteristics of the structure subject to linearly increasing compressive load, under the assumption of low interface friction. A simplified analytical model of the multi-layer structure is also formulated considering essential boundary and support conditions for each individual layer. The model revealed progressive hardening characteristics of the multilayer structure during compression due to sequential jamming of individual layers. The force-displacement characteristics of the design could thus be varied by varying the multi-layer structure parameters, such as number of layers, thickness of individual layers, material properties, and clearance between the successive layers. It is shown that the simplified analytical model could provide reasonably good estimate of the force-deflection properties of the structure in a computationally efficient manner. The analytical model is subsequently used to investigate the influences of variations in the multilayer structure parameters in a computationally efficient manner. It is shown that the proposed design offers superior tuning flexibility to realize desired force-displacement characteristics of the structure for developing scalable anthropomorphic robotic fingers of a compliant robotic hand, in addition to the cost-effective manufacturability.

Download or read book Dynamics and Control of Robotic Manipulators with Contact and Friction written by Shiping Liu and published by John Wiley & Sons. This book was released on 2018-11-15 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to the friction, contact and impact on robot control and force feedback mechanism Dynamics and Control of Robotic Manipulators with Contact and Friction offers an authoritative guide to the basic principles of robot dynamics and control with a focus on contact and friction. The authors discuss problems in interaction between human and real or virtual robot where dynamics with friction and contact are relevant. The book fills a void in the literature with a need for a text that considers the contact and friction generated in robot joints during their movements. Designed as a practical resource, the text provides the information needed for task planning in view of contact, impact and friction for the designer of a robot control system for high accuracy and long durability. The authors include a review of the most up-to-date advancements in robot dynamics and control. It contains a comprehensive resource to the effective design and fabrication of robot systems and components for engineering and scientific purposes. This important guide: Offers a comprehensive reference with systematic treatment and a unified framework Includes simulation and experiments used in dynamics and control of robot considering contact, impact and friction Discusses the most current tribology methodology used to treat the multiple–scale effects Contains valuable descriptions of experiments and software used Presents illustrative accounts on the methods employed to handle friction in the closed loop, including the principles, implementation, application scope, merits and demerits Offers a cohesive treatment that covers tribology and multi-scales, multi-physics and nonlinear stochastic dynamics control Written for graduate students of robotics, mechatronics, mechanical engineering, tracking control and practicing professionals and industrial researchers, Dynamics and Control of Robotic Manipulators with Contact and Friction offers a review to effective design and fabrication of stable and durable robot system and components.

Download or read book Design of Mechanical Programmability for Vibration actuated Robots and Shape changing Laminate Structures written by William Hakes Weston-Dawkes and published by . This book was released on 2022 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rigid robotic systems struggle to solve problems that require drastic shape changes, possess high environmental uncertainty, and involve direct interaction with humans. The present work investigates four different approaches to designing mechanically reprogrammable robotic systems. The mechanical properties of the four presented systems are controlled by re-programming their geometry, structural properties, or dynamic properties during operation. The first study explores the potential of vibration-based locomotion in a self-folded robotic system to characterize and achieve controllable locomotion that is easily incorporated into laminate structures. We describe the extension of two-dimensional bristle-bot models to a three-dimensional model that explores parameters that govern linear and angular velocity, and implement a self-folding laminate-manufactured bristle-bot robot. In the second study, we present a new method for achieving controllable adhesion by vibrating a flexible plate near a surface, which generates a strong and controllable normal attraction force while allowing free motion parallel to the surface. Spatial pressure measurements demonstrate that adhesion is localized to the center of the disc. We developed a mobile robot capable of robustly acquiring payloads and adhering to vertical and inverted surfaces. In the third study, we present a variable stiffness surgical retractor that can be folded and inserted into a patient through a small opening, can change to a stiff state and anchor atraumatically to the body to retract an organ, and can be subsequently refolded and removed from the body. We model the variable stiffness mechanism (layer jamming) to predict the maximum load a retractor can support and compare this to experiments. In the fourth study, we present a model to predict the length scales at which jamming contributes to the overall performance of an inflatable beam, serving as a limb of a hybrid hard/soft robot. We measure the performance of prototype jamming limbs in cantilever loading tests, and experimentally test a quadrupedal system, using experiments to inform the design process. Incorporating jamming reinforcement into inflatable beams provides improved stiffness and graceful failure rather than the catastrophic buckling that normally characterizes inflated cylindrical beams. Together, these studies illuminate the exciting potential of mechanically reprogrammable robotic systems composed of laminate structures.

Download or read book Structural Health Monitoring with Piezoelectric Wafer Active Sensors written by Victor Giurgiutiu and published by Academic Press. This book was released on 2014-06-20 with total page 1025 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Health Monitoring with Piezoelectric Wafer Active Sensors, Second Edition provides an authoritative theoretical and experimental guide to this fast-paced, interdisciplinary area with exciting applications across a range of industries. The book begins with a detailed yet digestible consolidation of the fundamental theory relating to structural health monitoring (SHM). Coverage of fracture and failure basics, relevant piezoelectric material properties, vibration modes in different structures, and different wave types provide all the background needed to understand SHM and apply it to real-world structural challenges. Moving from theory to experimental practice, the book then provides the most comprehensive coverage available on using piezoelectric wafer active sensors (PWAS) to detect and quantify damage in structures. Updates to this edition include circular and straight-crested Lamb waves from first principle, and the interaction between PWAS and Lamb waves in 1-D and 2-D geometries. Effective shear stress is described, and tuning expressions between PWAS and Lamb waves has been extended to cover axisymmetric geometries with a complete Hankel-transform-based derivation. New chapters have been added including hands-on SHM case studies of PWAS stress, strain, vibration, and wave sensing applications, along with new sections covering essential aspects of vibration and wave propagation in axisymmetric geometries. - Comprehensive coverage of underlying theory such as piezoelectricity, vibration, and wave propagation alongside experimental techniques - Includes step-by-step guidance on the use of piezoelectric wafer active sensors (PWAS) to detect and quantify damage in structures, including clear information on how to interpret sensor signal patterns - Updates to this edition include a new chapter on composites and new sections on advances in vibration and wave theory, bringing this established reference in line with the cutting edge in this emerging area

Download or read book Variable Stiffness Structures Via Mechanics Modification and Antagonistic Actuation in Soft Robotic Materials written by Emily A. Allen and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The soft robotics approach seeks to provide the efficiency and autonomy of robots while using soft materials that are safe for interaction with humans and delicate objects. The inherent weakness of flexible materials renders ordinary usage of soft materials inadequate for robots that need to exert large forces. In this paper, two classes of mechanisms for variable stiffness structures are explored: intrinsic variable stiffness and dual antagonistic actuation. This work proposes designs and modeling strategies for variable stiffness structures that incorporate smart materials (to enable modification of intrinsic mechanical properties), geometric patterning of low melting point materials (to enable directional stiffness control), and pneumatic/shape memory alloy antagonistic actuation (to enable independent control of stiffness and bending). Whereas other researchers have focused on controlling the magnitude of stiffness in soft materials, this paper also explores soft robotic structures with directional stiffness control. The mechanical properties of the materials are tested via tension, compression, and 3-point bend tests. Kinematic modeling of the patterned structure relies on the product of exponentials method for serial link robots, then incorporates tendon forces and selectable axes for the kinetic relationships. A finite element model is constructed in MATLAB to predict the configuration of the pneumatic/shape memory alloy actuator based on measured material properties. Each of the proposed designs are fabricated and tested to demonstrate their variable stiffness capabilities and compare with modeling results.

Download or read book Compliant Control of Variable Stiffness Actuator Considering Lower limb Robot Applications written by Lin Liu and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Develop Robotic Arm for Automated Guided Conveyor written by Francis Giang Japar and published by . This book was released on 2011 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is related to the mechanism of a robotic arm that serves as a tool to lift an object from one place to another where it is widely used in the factory. The study of this material was analyzed using computer software that can calculate the finite element of linear stress analysis of each mechanical components of robotic arm. Results of this analysis will be a reference to select suitable material. In this project, the aluminium 6061 was used. In addition, the selection of electrical components used in the robotic arm is also taken into account by calculating the inverse kinematic and forward kinematic of this robotic arm movement. Besides that, the forces exerted on the robotic arm are also calculated to ensure the mechanical components of the robotic arm is not easily broken or damaged. Referring to the result obtained, a robotic arm resistance depends on the motor used. Therefore, the compatibility of motor torque with the robotic arm design is made is important because it affects the stability of the robotic arm.

Download or read book Robotics and Automation Handbook written by Thomas R. Kurfess and published by CRC Press. This book was released on 2018-10-03 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the capability and utility of robots has increased dramatically with new technology, robotic systems can perform tasks that are physically dangerous for humans, repetitive in nature, or require increased accuracy, precision, and sterile conditions to radically minimize human error. The Robotics and Automation Handbook addresses the major aspects of designing, fabricating, and enabling robotic systems and their various applications. It presents kinetic and dynamic methods for analyzing robotic systems, considering factors such as force and torque. From these analyses, the book develops several controls approaches, including servo actuation, hybrid control, and trajectory planning. Design aspects include determining specifications for a robot, determining its configuration, and utilizing sensors and actuators. The featured applications focus on how the specific difficulties are overcome in the development of the robotic system. With the ability to increase human safety and precision in applications ranging from handling hazardous materials and exploring extreme environments to manufacturing and medicine, the uses for robots are growing steadily. The Robotics and Automation Handbook provides a solid foundation for engineers and scientists interested in designing, fabricating, or utilizing robotic systems.

Download or read book Compliant Robotic Arms for Inherently Safe Physical Human robot Interaction written by Yu She (Ph. D. in mechanical engineering) and published by . This book was released on 2018 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Static and dynamic models of the CLs are derived and verified by finite element analysis (FEA). To achieve a high efficiency and accuracy of the dynamic model, a mass-parameter optimization framework is developed for the pseudo-rigid-body (PRB) model. The proposed optimized PRB model can rapidly and precisely predict statics, kinematics, and dynamics for compliant mechanisms. A pHRI platform is then studied from the perspective of both theoretical model and experimental setup. The model provides general guidelines for selecting design parameters for the pHRI platform to achieve desired requirements, and the experimental platform validates the model and demonstrates that the CL design can increase safety for pHRI. This study explores the CL design with variable stiffness for safe pHRI, and expands the research arena with respect to human-safe robot design. The proposed CL designs hold the advantages of larger bandwidth and fewer injury consequences than those of the CJ designs. The developed dynamic model (optimized PRB model) of the CL design has great advantages on economic calculation. The grandly shortened computation of the dynamics model is beneficial for real-time control. The whole pHRI model can be used for evaluations of selected design parameters and provides guidance to customize designs for critical requirements.

Download or read book Handbook of Compliant Mechanisms written by Larry L. Howell and published by John Wiley & Sons. This book was released on 2013-04-01 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fully illustrated reference book giving an easy-to-understand introduction to compliant mechanisms A broad compilation of compliant mechanisms to give inspiration and guidance to those interested in using compliant mechanisms in their designs, the Handbook of Compliant Mechanisms includes graphics and descriptions of many compliant mechanisms. It comprises an extensive categorization of devices that can be used to help readers identify compliant mechanisms related to their application. It also provides chapters on the basic background in compliant mechanisms, the categories of compliant mechanisms, and an example of how the Compendium can be used to facilitate compliant mechanism design. Fully illustrated throughout to be easily understood and accessible at introductory levels Covers all aspects pertaining to classification, elements, mechanisms and applications of compliant mechanisms Summarizes a vast body of knowledge in easily understood diagrams and explanations Helps readers appreciate the advantages that compliant mechanisms have to offer Practical approach is ideal for potential practitioners who would like to realize designs with compliant mechanisms, members and elements Breadth of topics covered also makes the book a useful reference for more advanced readers Intended as an introduction to the area, the Handbook avoids technical jargon to assist non engineers involved in product design, inventors and engineers in finding clever solutions to problems of design and function.

Download or read book Smart Devices and Machines for Advanced Manufacturing written by Lihui Wang and published by Springer Science & Business Media. This book was released on 2008-02-28 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a collection of quality chapters on the state-of-the-art of research efforts in the area of smart devices and novel machine design, as well as their practical applications to enable advanced manufacturing. The first section presents a broad-based review of several key areas of research in smart devices and machines. The second section is focused on presenting an in-depth treatment of a particular device or machine. The book will be of interest to a broad readership.