Design of large-displacement compliant joints
01 Jan 2002-Journal of Mechanical Design (American Society of Mechanical Engineers)-Vol. 127, Iss: 4, pp 788-798
TL;DR: In this article, the drawbacks of typical flexure connectors are investigated and cataloged, and several new designs for highly effective, kinematically-behaved compliant joints are proposed.
Abstract: Flexure joints are widely used to approximate the function of traditional mechanical joints, while offering the benefits of high precision, long life, and ease of manufacture. This paper investigates and catalogs the drawbacks of typical flexure connectors and presents several new designs for highly-effective, kinematically-behaved compliant joints. A revolute and a translational compliant joint are proposed (Figure 1), both of which offer great improvements over existing flexures in the qualities of (1) large range of motion, (2) minimal axis drift, (3) increased off-axis stiffness, and (4) reduced stress-concentrations. Analytic stiffness equations are developed for each joint and parametric computer models are used to verify their superior stiffness properties. A catalog of design charts based on the parametric models is also presented, allowing for rapid sizing of the joints for custom performance. Finally, two multi-degree-of-freedom joints are proposed as modifications to the revolute joint. These include a compliant universal joint and a compliant spherical joint, both designed to provide high degrees of compliance in the desired direction of motion and high stiffness in other directions.Copyright © 2002 by ASME
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TL;DR: It is shown how novel manufacturing paradigms enable the creation of the mechanical and aeromechanical subsystems of a microrobotic device that is capable of Diptera-like wing trajectories, and the results are a uniquemicrorobot: a 60 mg robotic insect that can produce sufficient thrust to accelerate vertically.
Abstract: Biology is a useful tool when applied to engineering challenges that have been solved in nature. Here, the emulous goal of creating an insect-sized, truly micro air vehicle is addressed by first exploring biological principles. These principles give insights on how to generate sufficient thrust to sustain flight for centimeter-scale vehicles. Here, it is shown how novel manufacturing paradigms enable the creation of the mechanical and aeromechanical subsystems of a microrobotic device that is capable of Diptera-like wing trajectories. The results are a unique microrobot: a 60 mg robotic insect that can produce sufficient thrust to accelerate vertically. Although still externally powered, this micromechanical device represents significant progress toward the creation of autonomous insect-sized micro air vehicles.
878 citations
Cites background from "Design of large-displacement compli..."
...Instead, flexures are used in place of revolute joints [25] (see Fig....
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TL;DR: This origami-inspired robot can fold itself in 4 minutes and walk away without human intervention, demonstrating the potential both for complex self-folding machines and autonomous, self-controlled assembly.
Abstract: Origami can turn a sheet of paper into complex three-dimensional shapes, and similar folding techniques can produce structures and mechanisms. To demonstrate the application of these techniques to the fabrication of machines, we developed a crawling robot that folds itself. The robot starts as a flat sheet with embedded electronics, and transforms autonomously into a functional machine. To accomplish this, we developed shape-memory composites that fold themselves along embedded hinges. We used these composites to recreate fundamental folded patterns, derived from computational origami, that can be extrapolated to a wide range of geometries and mechanisms. This origami-inspired robot can fold itself in 4 minutes and walk away without human intervention, demonstrating the potential both for complex self-folding machines and autonomous, self-controlled assembly.
815 citations
TL;DR: In this paper, the authors present a new fabrication process called smart composite microstructures (SCM) for integrating rigid links and large angle flexure joints through a laser micromachining and lamination process.
Abstract: Mobile microrobots with characteristic dimensions on the order of 1 cm are difficult to design using either microelectromechanical systems technology or precision machining. This is due to the challenges associated with constructing the high strength links and high-speed, low-loss joints with micron scale features required for such systems. Here, we present an entirely new framework for creating microrobots, which makes novel use of composite materials. This framework includes a new fabrication process termed smart composite microstructures (SCM) for integrating rigid links and large angle flexure joints through a laser micromachining and lamination process. We also present solutions to actuation and integrated wiring issues at this scale using SCM. Along with simple design rules that are customized for this process, our new complete microrobotic framework is a cheaper, quicker, and altogether superior method for creating microrobots that we hope will become the paradigm for robots at this scale.
364 citations
01 Jan 2007
TL;DR: A classification scheme for flexibility is proposed, and its application to reconfigurable system design is explored, and design techniques that incorporate flexibility both in the design (form) and performance (function) space are presented.
Abstract: The demands on today’s products have become increasingly complex as customers expect enhanced performance across a variety of diverse and changing system operating conditions. Reconfigurable systems are capable of undergoing changes in order to meet new objectives, function effectively in varying operating environments, and deliver value in dynamic market conditions. Research in the design of such responsive and changeable systems, however, currently faces impediments in effective and clear discourse due to ambiguity in terminology. Definitions of the terms flexibility and reconfigurability, two related concepts in reconfigurable system design, are explored based on their original lexical meanings and current understanding in design literature. Design techniques that incorporate flexibility both in the design (form) and performance (function) space are presented. Based upon this literature survey, a classification scheme for flexibility is proposed, and its application to reconfigurable system design is explored. This paper also presents recent methodologies for reconfigurable system design and poses important research questions that remain to be investigated.
138 citations
TL;DR: The Lamina Emergent Torsional Joint (LET) as mentioned in this paper is a compliant joint suitable for applications where large angular rotation is desired, but high off-axis stiffness is not as critical.
110 citations
Cites background from "Design of large-displacement compli..."
...[5] investigated large displacement compliant joints, where they proposed a new joint for translation and another for rotation....
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References
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Book•
27 Nov 2002TL;DR: The second edition of Compliant Mechanisms: Design of Flexure Hinges as mentioned in this paper provides practical answers to the design and analysis of devices that incorporate flexible hinges by means of a bottom-up compliance (flexibility) approach.
Abstract: With a rigorous and comprehensive coverage, the second edition of Compliant Mechanisms: Design of Flexure Hinges provides practical answers to the design and analysis of devices that incorporate flexible hinges. Complex-shaped flexible-hinge mechanisms are generated from basic elastic segments by means of a bottom-up compliance (flexibility) approach. The same compliance method and the classical finite element analysis are utilized to study the quasi-static and dynamic performances of these compliant mechanisms. This book offers easy-to-use mathematical tools to investigate a wealth of flexible-hinge configurations and two- or three-dimensional compliant mechanism applications.
FEATURES
Introduces a bottom-up compliance-based approach to characterize the flexibility of new and existing flexible hinges of straight- and curvilinear-axis configurations
Develops a consistent linear lumped-parameter compliance model to thoroughly describe the quasi-static and dynamic behavior of planar/spatial, serial/parallel flexible-hinge mechanisms
Utilizes the finite element method to analyze the quasi-statics and dynamics of compliant mechanisms by means of straight- and curvilinear-axis flexible-hinge elements
Covers miscellaneous topics such as stress concentration, yielding and related maximum load, precision of rotation of straight- and circular-axis flexible hinges, temperature effects on compliances, layered flexible hinges and piezoelectric actuation/sensing
Offers multiple solved examples of flexible hinges and flexible-hinge mechanisms.
This book should serve as a reference to students, researchers, academics and anyone interested to investigate precision flexible-hinge mechanisms by linear model-based methods in various areas of mechanical, aerospace or biomedical engineering, as well as in robotics and micro-/nanosystems.
651 citations
01 Jan 1965
609 citations
"Design of large-displacement compli..." refers background in this paper
...fillet joints) were first analyzed by Paros and Weisbord (1965) and have since become well understood by many researchers and designers....
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Book•
01 Mar 1996
TL;DR: In this paper, the authors present a list of software included on CD-ROMs, including TKSOLVER, MathCAD, and Answer to Selected Problems (ABP).
Abstract: 1. Introduction to Design. 2. Materials and Process. 3. Load Determination. 4. Stress, Strain, and Deflection. 5. Static Failure Theories. 6. Fatigue Failure Theories. 7. Surface Failure. 8. Design Case Studies. 9. Shafts, Keys, and Couplings. 10. Bearings and Lubrication. 11. Spur Gears. 12. Helical, Bevel, and Worm Gears. 13. Spring Design. 14. Screws and Fasteners. 15. Clutches and Brakes. Appendix A. Cross-Sectional Properties. Appendix B. Mass Properties. Appendix C. Material Properties. Appendix D. Beam Tables. Appendix E. Stress Concentration Factors. Appendix F. Introduction to TKSOLVER. Appendix G. Introduction to MathCAD. Appendix H. Answers to Selected Problems. Appendix I. List of Software Included on CD-ROM.
528 citations
Book•
08 Aug 2000
TL;DR: Flexure Design: Advantages and Disadvantages of Flexures as discussed by the authors The main advantages and disadvantages of flexible design are: Basic Elasticity. Fatigue. Vibrations and Natural Frequencies of Continuous Systems.
Abstract: Introduction: Advantages and Disadvantages of Flexures. Goals of Flexure Design. Essentials: Basic Elasticity. Behavior of Materials. Fatigue. Bending of Symmetric Beams. Rigid Body Dynamics: Linear Systems Theory. Vibrations and Natural Frequencies of Continuous Systems. Flexure Elements: Leaf Type Springs. Notch Hinge. Two Axis Hinges. The Four Bar Link. Flexure Systems: General Model for Dynamics of planar Flexures. Hinges of Rotational Symmetry: The Disc Coupling. Rotationally Symmetric Leaf Type Hinge. The Bellows as a Flexure Element. Levers. Manufacturing and Assembly Considerations: Machining and Heat Treatment of Some Common Flexure Materials.
481 citations
447 citations
"Design of large-displacement compli..." refers background in this paper
...These joints have also been applied by Howell and Midha (1994) to develop the field of psuedo-rigidbody compliant mechanisms....
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