To see the other types of publications on this topic, follow the link: Kinematics and compliance.
Dissertations / Theses on the topic 'Kinematics and compliance'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 35 dissertations / theses for your research on the topic 'Kinematics and compliance.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Labbé, Anton, and Benjamin Ström. "Construction of a Selective Compliance Articulated Robot Arm : And evaluation of its accuracy." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296163.
Full textAbstract:
The concept of a robotic manipulator is widely used throughout many industries. In this project, a manipulator of the type SCARA, selective compliance articulated robot arm, is constructed. The aim was to examine how such a robot could be constructed using 3D-printing and how accurate it would be. Other than 3D-printing, parts in the form of guiding rods, lead screw, bearings, pulleys and timing belts were used. Together with a microcontroller, the robot operates using three stepper motors. In the end it resulted in a SCARA with reasonable accuracy considering the methods used, more specifically the largest average error was 3.6cm in the X direction and 2.3 cm in the Y direction. The largest drawback of the final construction was the negative balance between tightening the belts and friction in the inner joint. Tightening the belts meant larger friction and thereby undesired movement properties. Doing the opposite meant that the belts could start slipping and enabled backlash.Konceptet av en robotarm används brett inom många industrier. Detta projekt syftar till att konstruera en robot avtypen SCARA, selective compliance articulated robot arm. Målet var att undersöka hur en sådan robot kan 3D-printas och dess precision. Förutom 3D-printade delar användes även guidestänger, kullager, kamremmar och remskivor. Robotens rörelser styrs tillsammans med en mikrokontroller och tre stegmotorer. Med tillvägagångssätten i åtanke resulterade projektet in en SCARA med rimlig precision. Mer specifikt var medelfelet 3.6 cm i X-led och 2.3 cm i Y-led. Den största nackdelen med den slutgiltiga konstruktionenvar den negativa jämvikten mellan att spänna kamremmarna och friktionen i den inre armleden. Att spänna kamremmarna innebar en ökning i friktion och därmed oönskade rörelseegenskaper. Att göra tvärtom innebar att bältena löpte större risk att glida ur och möjliggjorde dödgång.
2
Suchý, Jan. "Měření poddajností zavěšení kol." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231523.
Full textAbstract:
The thesis is focused on the method of determining the position of the wheel using photogrammetric equipment Tritop. Verification of the method is performed by measuring of the Formula Student Dragon II. Measured data are processed by algorithm for calculating compiled in Matlab software. The final section describes a concept the measurement of the suspension flexibility on the UADI device.
3
Wiedmann, Stephen Louis. "Kinematic Analysis of a Threaded Fastener Assembly." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31685.
Full textAbstract:
The demands for an increase in productivity and reduced assembly costs require engineers to automate solutions that replace manual labor. This work concentrated on a common assembly primitive, threaded fastener insertion, in an effort to determine the nature of contact between a bolt and nut during thread mating. The assembly problem was initially simplified as a two-dimensional analysis to gain an understanding about how contacts between the bolt and nut change during counter-clockwise motion. Tessellated solid models were used during three-dimensional collision analysis in such a way that the approximate location of the contact point was enumerated. The advent of a second contact point presented a more constrained contact state since we are interested in maintaining both contacts; thus the bolt rotated about a vector defined by the initial two contact points until a third contact location was found. By analyzing the depth of intersection of the bolt into the nut as well as the vertical movement of the origin of the bolt reference frame, we determined that there are three types of contacts states present: unstable two-point, quasi-stable two-point, stable three point. Though the unstable case remains to be deciphered, the parametric equations derived in this work can be used without modification to create a full spectrum of maps at any point in the history of a threaded assembly problem. We investigated 81 potential orientations, each of which has its own set of contact points. From this exhaustive examination, we are capable of detailing a contact state history and, from this, have the potential to develop a constraint network.Master of Science
4
Culpepper, Martin L. (Martin Luther). "Design and application of compliant quasi-kinematic couplings." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9260.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.Includes bibliographical references (p. 113-116).
Better precision at lower costs is a major force in design and manufacturing. However, this is becoming increasingly difficult to achieve as the demands of many location applications are surpassing the practical performance limit (~ five microns) of low-cost couplings. The absence of a means to meet these requirement has motivated the development of the Quasi-Kinematic Coupling (QKC). This thesis covers the theoretical and practical considerations needed to model and design QKCs. In a QKC, one component is equipped with three spherical protrusions while the other contains three corresponding conical grooves. Whereas Kinematic Couplings rely on six points of contact, the six arcs of contact between the mated protrusions and grooves of QKCs result in a weakly over-constrained coupling, thus the name Quasi-Kinematic. QKCs are capable of sub-micron repeatability, permit sealing contact as needed in casting, and can be economically mass produced. The design and application of a QKC is demonstrated via a case study on the location of two engine components. Integration of the QKC has improved coupling precision from 5 to 0.7 microns. In addition, this QKC uses 60% fewer precision features, 60% fewer pieces, costs 40% less per engine, and allows feature placement tolerances which are twice as wide as those of the previous dowel-pin-type coupling.
by Martin L. Culpepper.
S.M.
5
Jagirdar, Saurabh. "Kinematics of curved flexible beam." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001853.
Full text
6
Swiss, Dallin R. "Springback Force Considerations in Compliant Haptic Interfaces." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5835.
Full textAbstract:
This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an analytical approach to predict the motor torques needed to actively compensate for the effects of springback. This approach relies on virtual work analyses of the haptic pantograph to determine the springback forces, compensation torques, haptic workspace, and available haptic force after compensation. A key to estimating the available haptic force is knowing that the force capability is different depending on the local springback force. If a component of the desired haptic force aligns with the springback force, then the two can work together, thus increasing the maximum magnitude of available haptic force beyond the nominal amount. Analytical and experimental results are presented. A detailed method of implementation is given along with a hardware demonstration of active compensation.
7
Alfattani, Rami. "Design of Shape-Morphing Structures Consisting of Bistable Compliant Mechanisms." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7725.
Full textAbstract:
This dissertation presents a design concept for shape-morphing structures that have two stable configurations. The design concept defines the methodology of transforming a planar structural shape into spatial structural shape using bistable compliant mechanisms. Bistable complaint mechanisms are used to achieve structural stable configurations. The dissertation incorporating geometrical relationships for the mechanisms that form the primary structure described in step-by-step process. This dissertation implements the design layouts for designer to creating shape-morphing structures including origami. The novel contribution of the work is classified in three models. The first model presents a methodology to induce bistability behavior into an origami reverse fold and partially spherical compliant mechanism. The second model presents the design and development of a bistable triangle-shaped compliant mechanism with motion limits and dwell behavior at the two stable configurations. This mechanism can be arrayed to create shape-morphing structures. The third model presents a design and development for a collapsible bistable compliant mechanism used for a shape morphing lamina-emergent frustum. Finally, physical prototypes of all models are presented as proof of concept.
8
Quinn, Cheney. "Vliv viskoelasticity a provozních podmínek na tření poddajných kontaktů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444274.
Full textAbstract:
Poddajné kontakty obsahující polymerní nebo pryžové členy lze nalézt v technických i biologických aplikacích. I přes vývoj v této oblasti existují efekty, které ovlivňují tribologické aspekty těchto kontaktů, a je třeba je dále zkoumat. Tato práce se zabývá vlivy kinematických podmínek, konfigurace, viskoelasticity a viskozity maziva na tření v mazaných poddajných kontaktech. Výsledky byly použity k vývoji numerického modelu pro predikci kapalinového tření v poddajných kontaktech. K objasnění chování poddajných kontaktů bylo použito zařízení Mini Traction Machine (MTM) v konfiguraci ball-on-disc, což umožnilo zkoumání zmíněných vlivů. Z poznatků z technické oblasti bylo zjištěno, že viskoelasticita se projevuje ve všech konfiguracích, tedy soft-on-hard, hard-on-soft a soft-on-soft, a její efekt je nejvýznamnější v konfiguracích s poddajným diskem. Data dále ukazují, že poměr skluzu a valení má vliv na valivé tření což je v rozporu se současnou literaturou. Výsledky z biologické oblasti naznačují, že za určitých podmínek lze nahradit nativní kapalinu jednoduchým mazivem. Tyto poznatky mohou posloužit jako odrazový můstek pro další studie zabývající se poddajnými kontakty.
9
Zimmerman, Trent Karl. "A Definition and Demonstration of Developable Mechanisms." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7343.
Full textAbstract:
There is an increasing need for compact mechanical systems that can accomplish sophisticated tasks. Technologies like ortho-planar and lamina emergent mechanisms (LEMs) have been developed to satisfy needs like these by stowing in planar sheets from which they emerge to perform their function. They can be compact, lightweight, monolithic, scalable, and can withstand harsh environments. They are limited, however, by their base element---planar surfaces. Applications requiring these advantages often include curved surfaces, like aircraft wings, needles, and automotive bodies. In this research, developable mechanisms are presented as a solution to satisfy the need for mechanisms that can conform to or emerge from curved surfaces. Foundational principles which enable designers to leverage the advantages of developable mechanisms are described herein.Developable mechanisms result from the union of mechanisms and developable surfaces. Developable (flattenable) surfaces act as a fitting medium because of their particular advantages in manufacturability and how well they accompany four-link, revolute joint (4R) mechanisms. The definition, including specific qualifying criteria, for developable mechanisms is given. Certain types of mechanisms and classes of developable surfaces can be combined to satisy that criteria. Developable mechanism sub-classes are defined as planar, cylindrical, conical and tangent developable mechanisms. It is shown that planar and spherical mechanisms can be used to create cylindrical and conical developable mechanisms, respectively. The Bennett and other 7R mechanisms can be used for tangent developable mechanisms. Steps for developable mechanism creation are presented, and several physical prototypes are provided to demonstrate feasibility.The cylindrically curved Lamina Emergent Torsional (LET) joint is offered as an enabling technology for producing compliant developable mechanisms. A mathematical model predicting force-deflection and stress behavior is provided and verified. The relationship between stiffness and strain energy storage for curved sheet materials with incorporated LET joints is explored. Material shape factors are used to derive an effective modulus of elasticity and an effective modulus of resilience, which are compared with original values on an Ashby plot. While there is a decrease in the modulus of resilience, there is a much more significant decrease in the modulus of elasticity. A material performance index is provided as an example for determining suitable materials for a given stiffness-reduction application. It is shown that the cylindrically curved LET joint makes it possible to create highly flexible joints that maintain much of their energy storage capability in curved sheet materials.
10
Jones, Caitrin Elizabeth. "The design of a compliant underwater angle sensor to investigate the kinematics of burrowing razor clams." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54492.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 38).
This paper presents the detailed design process for a compliant underwater angle sensor to be used in analyzing the precise burrowing motions of razor clams in order to aid in the development of intelligent anchoring devices. The angle sensor was developed using a set of specific functional requirements, theoretical kinematic and structural models, and an iterative prototyping process. The resulting sensor is a device that can measure the angle between the two halves of a clam's shell versus time using a thermal-centric strain gauge configuration. The device is saltwater compatible, does not hinder the motions of the clam and only increases the axial drag on the clam by 2.3 to 5.5%. Data can now be collected using this sensor that will be important to creating a strategy for the coordination of the movements of a robotic anchor that would improve upon existing anchoring technologies for marine applications ranging from small boats, to Autonomous Underwater Vehicles (AUVs), to spy equipment.
by Caitrin Elizabeth Jones.
S.B.
11
Wagner, Timothy Paul. "The Mechanical Design of a Suspension Parameter Identification and Evaluation Rig (SPIdER) for Wheeled Military Vehicles." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322502477.
Full text
12
Zhou, Lifeng. "Design Modeling and Analysis of Compliant and Rigid-Body DNA Origami Mechanisms." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492793740662906.
Full text
13
Huang, Ji Ming. "Design, modeling and control of a compliant parallel XY micro-motion stage with complete decoupling property." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493609.
Full text
14
Sayginer, Ege. "Modelling The Effects Of Half Circular Compliant Legs On The Kinematics And Dynamics Of A Legged Robot." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12612071/index.pdf.
Full textAbstract:
RHex is an autonomous hexapedal robot capable of locomotion on rough terrain. Up
to now, most modelling and simulation efforts on RHex were based on the linear leg
assumption. These models disregarded what might be seen as the most characteristic
feature of the latest iterations of this robot: the half circular legs. This thesis
focuses on developing a more realistic model for this specially shaped compliant leg
and studying its effects on the kinematics and dynamics of the resulting platform.
One important consequence of the half circular compliant leg is the resulting rolling
motion. Due to rolling, the rest length of the leg changes and the leg-ground contact
point moves. Another consequence is the varying stiffness of the legs due to the
changing rest length. These effect the resulting behaviour of any platform using these
legs. In the first part of the thesis we are studying the effects of the half circular
leg morphology on the kinematics of RHex using a simple planar model. The rest
of the studies within the scope of this thesis focuses on the effect of the half circular
compliant legs on the dynamics of a single legged hopping platform with a point mass.
The formulation derived in this work is successfully integrated in a readily working
but rather simple model of a single legged hopping system. We replace the equations
of the straight leg in this model by the equations of the half circular compliant leg.
Realistic results are obtained in the simulations and these results are compared to
those obtained by the simpler constant stiffness straight leg model. This more realistic
leg model brings us the opportunity to further study the effects of this leg morphology,
in particular the positive effects of the resulting rolling motion on platform stability.
15
León, Alejandro. "A pseudo-rigid-body model for spherical mechanisms : the kinematics and elasticity of a curved compliant beam." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002272.
Full text
16
León, Alejandro. "A pseudo-rigid-body model for spherical mechanisms: The kinematics and elasticity of a curved compliant beam." Scholar Commons, 2007. http://scholarcommons.usf.edu/etd/2259.
Full textAbstract:
This thesis improves a previous kinematic analysis and develops the elastic portion of the analysis of a curved compliant beam. This analysis is used to develop a Pseudo-Rigid-Body Model for the curved compliant beam. The Pseudo-Rigid-Body Model consist of kinematic and elastic parameters which can be used to simplify the computation of the large deflections of the beam as it undergoes spherical motion. The kinematic parameters that are developed are the characteristic radius, Gamma*length, the parametric angle coefficient, c_theta, and the kinematic parametrization limit, Capital_theta_max(Gamma). The elastic parameters developed are the stiffness coefficient, K_theta, and the elastic parameterization limit, Capital_theta_max(K). Additionally, curve fit parameters are developed which enable the calculation of the stress in curved beam as it deflects.
17
Seereeram, Videsh Ramjas. "Compliant shell mechanisms." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610867.
Full text
18
Wiersdorf, Jason Matthew. "Preliminary Design Approach for Prosthetic Ankle Joints Using Compliant Mechanisms." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/721.
Full textAbstract:
The objective of this thesis is to develop design approaches and models for prosthetic ankle joints using kinematic models of the human ankle and compliant mechanisms technology. Compliant mechanisms offer several potential design advantages over traditional rigid-body designs including high reliability and low cost. These design advantages are ideal for use in prosthetics. Some prosthetic ankle/foot systems currently on the market have multiple degrees of freedom yet are expensive. Additionally, even though these systems have multiple degrees of freedom, none of them are designed after the actual movements of the biological ankle. In this thesis a two, single degree-of-freedom hinge joint model, which is a kinematic model based on the biological ankle during walking, is used to develop compliant prosthetic ankle joints. The use of the model together with compliant mechanisms may provide the ability to develop highly functional prosthetic ankle joints at a lower cost than current high-performance prosthetic systems. Finally, a design approach for ankles may facilitate future development for knees, hips or other biological joints.
19
Ramirez, Issa Ailenid. "Pseudo-Rigid-Body Models for Approximating Spatial Compliant Mechanisms of Rectangular Cross Section." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5562.
Full textAbstract:
The objective of the dissertation is to develop and describe kinematic models (Pseudo-Rigid-Body Models) for approximating large-deflection of spatial (3D) cantilever beams that undergo multiple bending motions thru end-moment loading. Those models enable efficient design of compliant mechanisms, because they simply and accurately represent the bending and stiffness of compliant beams.
To accomplish this goal, the approach can be divided into three stages: development of the governing equations of a flexible cantilever beam, development of a PRBM for axisymmetric cantilever beams and the development of spatial PRBMs for rectangular cross-section beam with multiple end moments.
The governing equations of a cantilever beam that undergoes large deflection due to force and moment loading, contains the curvature, location and rotation of the beam. The results where validated with Ansys, which showed to have a Pearson's correlation factor higher than 0.91.
The resulting deflections, curvatures and angles were used to develop a spatial pseudo-rigid-body model for the cantilever beam. The spatial pseudo-rigid-body model consists of two links connected thru a spherical joint. For an axisymmetric beam, the PRB parameters are comparable with existing planar PRBMs. For the rectangular PRBM, the parameters depend on the aspect ratio of the beam (the ratio of the beam width over the height of the cross-section). Tables with the parameters as a function of the aspect ratio are included in this work.
20
Guo, Jiajie. "Effects of joint constraints on deformation of multi-body compliant mechanisms." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45971.
Full textAbstract:
Motivated by the interests to understand bio-structure deformation and exploit their advantages to create bio-inspired systems for engineering applications, a curvature-based model for analyzing compliant mechanisms capable of large deformation in a three dimensional space has been developed. Unlike methods (such as finite element) that formulate problems based on displacements and/or rotational angles, superposition holds for curvatures in the case of finite rotation but not for rotational angles; thus the curvature-based formulation presents an advantage in presenting nonlinear geometries. Along with a generalized constraint that relaxes traditional boundary constraints (such as fixed, pinned or sliding constraint) on compliant mechanisms, the method of deriving the compliant members in the same global referenced frame is presented. The attractive features of the method, which greatly simplifies the models and improves the computation efficiency of multi-body system deformation where compliant beams play an important role, have been experimentally validated. To demonstrate the applicability of this proposed method to a broad spectrum of applications, three practical examples are given; the first example verifies the generalized constraint by analyzing the multi-axis rotation motion within a natural human knee joint and investigates the human-exoskeleton interactions through dynamic analysis. The second example studies a deformable bio-structure by incorporating the generalized joint constraint into the curvature-based model for automated poultry meat processing. The last example designs a bio-inspired robot with a compliant mechanism to serve as a flexonic mobile node for ferromagnetic structure health monitoring. The analytical models have been employed (with experimental validation) to investigate the effects of different joint constraints on the mechanism deformations. It is expected that the proposed method will find a broad range of applications involving compliant mechanisms.
21
Chimento, Jairo Renato. "A 3-D Pseudo-Rigid-Body Model for Rectangular Cantilever Beams with an Arbitrary Force End-Load." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/4993.
Full textAbstract:
This dissertation introduces a novel three-dimensional pseudo-rigid-body model (3-D PRBM) for straight cantilever beams with rectangular cross sections. The model is capable of capturing the behavior of the neutral axis of a beam loaded with an arbitrary force end-load. Numerical integration of a system of differential equations yields approximate displacement and orientation of the beam's neutral axis at the free end, and curvatures of the neutral axis at the fixed end. This data was used to develop the 3-D PRBM which consists of two torsional springs connecting two rigid links for a total of 2 degrees of freedom (DOF). The 3-D PRBM parameters that are comparable with existing 2-D model parameters are characteristic radius factor (mean: γ = 0.8322), bending stiffness coefficient (mean: KΘ = 2.5167) and parametric angle coefficient (mean: cΘ = 1.2501). New parameters are introduced in the model in order to capture the spatial behavior of the deflected beam, including two parametric angle coefficients (means: cΨ = 1.0714; cΦ = 1.0087). The model is verified in a few locations using ANSYSTM and its use in the design of compliant mechanisms is illustrated through spatial compliant versions of crank slider and double slider mechanisms.
22
Shi, Hongliang. "Modeling and Analysis of Compliant Mechanisms for Designing Nanopositioners." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385484917.
Full text
23
Alqasimi, Ahmad. "Design Of Shape Morphing Structures Using Bistable Elements." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5897.
Full textAbstract:
This dissertation presents new concepts and methodology in designing shape-morphing structures using bistable elements. Developed using the Pseudo-Rigid-Body Model (PRBM), linear bistable compliant mechanism elements produce predictable and controllable length changes. Step-by-step design procedures are developed to guide the design process of these bistable elements. Two different examples of Shape-Morphing Space Frames (SMSFs) were designed and prototyped utilizing the bistable linear elements in a single-layer grid, in addition to flexures and rigid links, to morph a cylindrical space frame into both a hyperbolic and a spherical space frame. Moreover, bistable unit-cell compliant-mechanism elements were also developed to morph a compact structure from a specific initial shape to a final specific shape. The detailed design of those unit cells were done using Computer-aided design (CAD) software following a novel design procedure to transform a one-degree-of-freedom mechanism into a structure with sufficient compliance within its links to toggle between two chosen stable positions. Two different design examples were investigated in this research and prototyped to demonstrate the ability to morph disks into a hemisphere or a sphere with the structure being stable in both states (disk and sphere).
24
Perez, Daniel Eduardo. "Shield Design for Maximum Deformation in Shape-Shifting Surfaces." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4561.
Full textAbstract:
This research presents the initial studies and results on shield design for Shape-Shifting Surfaces (SSSs) seeking maximum compression and maximum expansion of a unit-cell. Shape-Shifting Surfaces (SSSs) are multilayered surfaces that are able to change shape while maintaining their integrity as physical barriers. SSSs are composed of polygonal unit-cells, which can change side lengths and corner angles. These changes are made possible by each side and corner consisting of at least two different shields, or layers of material. As the layers undergo relative motion, the unit-cell changes shape. In order for the SSS to retain its effectiveness as a barrier, no gaps can open between different layers. Also, the layers cannot protrude past the boundaries of the unit-cell. Based on these requirements, using equilateral triangle unit-cells and triangular shields, a design space exploration was performed to determine the maximum deformation range of a unit-cell. It was found that the triangular shield that offered maximum expansion and compression ratio is a right triangle with one angle of 37.5 degrees and its adjacent side equal to 61% of the side of the unit-cell. The key contribution of this paper is a first algorithm for systematic SSS shield design. Possible applications for SSSs include protection, by creating body-armor systems; reconfigurable antennas able to broadcast through different frequencies; recreational uses, and biomedical applications.
25
McCrate, Mark P. "Modern Mechanical Automata." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1291146053.
Full text
26
Jaroš, Tomáš. "Utváření mazacího filmu v poddajném kontaktu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318376.
Full textAbstract:
This diploma thesis deals with the study of film formation in compliant contact. Primary attention is dedicated to the influence of the entrainment speed and slide-to-roll ratio (SRR) on the central film thickness. Based on a research study of the available experimental methods, the fluorescence microscopy was used to achieve the aim of the work. Experiments were realized in ball-on-disk configuration. Firstly, a validation of the method was performed where the solid contact of the ceramic ball and the glass disk was analyzed. Since the measured values were in a good agreement with the theoretical prediction, a ball of NBR rubber material, which is commonly used for production of lip seals and o-rings, was subsequently used. The experimental measurements were performed under pure rolling and rolling/sliding conditions when the entrainment speeds varied in the range from 10 to 400 mm / s. A constant load of 0.2 N was applied. The measured data were then compared to the theoretical predictions for compliant contacts. The results showed that the thickness of the lubricating film gradually increases with increasing entrainment speed, which corresponds to theoretical assumption. Against expectations, evident influence of SRR on the film formation has been observed. In the last part of the thesis the measured data are confronted with previously published studies. Finally, some limitations of this study are discussed and recommendations for further improvement of the used experimental method are suggested.
27
Urban, Marek. "Návrh zavěšení kol Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417557.
Full textAbstract:
Tato práce se se zabývá návrhem kinematiky zavěšení kol obou náprav. Na základě analýz jízdních dat, multi-body simulací v softwaru Adams Car, simulací v Matlabu a analytických kalkulací v Mathcadu, je navržena řada změn s cílem zlepšit jízdní vlastnosti vozu Formule student, tyto změny jsou následně implementovány do CAD modelu vozu. Jednotlivé změny kinematiky náprav jsou provedeny na základě analýzy konkrétního problému, který se snaží řešit. Jednou z problematik je zástavbová náročnost systému odpružení a zavěšení zadních kol, zde je cílem snížit hmotnost, výšku těžiště a moment setrvačnosti. Další problematikou je geometrie předního kola, kde je cílem zlepšit využití pneumatik a snížit síly v řízení. Dále se práce zabývá simulacemi elastokinematiky zadní nápravy, součástí je také návrh měřícího zařízení. V poslední části je zkoumán vliv provedených změn i elastokinematiky na jízdní dynamiku vozu v ustálených stavech za pomocí MM metody simulované s modelem celého vozu v Adams Car a zpracované v Matlabu.
28
Logan, Philip James. "A Planar Pseudo-Rigid-Body Model for Cantilevers Experiencing Combined Endpoint Forces and Uniformly Distributed Loads Acting in Parallel." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5730.
Full textAbstract:
This dissertation describes the development and effectiveness of a mathematical model used to predict the behavior of cantilever beams whose loading conditions include parallel combinations of evenly distributed loads and endpoint forces. The large deflection of cantilever beams has been widely studied. A number of models and mathematical techniques have been utilized in predicting the endpoint path coordinates and load-deflection relationships of such beams. The Pseudo-Rigid-Body Model (PRBM) is one such method which replaces the elastic beam with rigid links of a parameterized pivot location and torsional spring stiffness. In this paper, the PRBM method is extended to include cases of a constant distributed load combined with a parallel endpoint force. The phase space of the governing differential equations is used to store information relevant to the characterization of the PRBM parameters. Correction factors are also given to decrease the error in the load-deflection relationship and extend the angular range of the model, thereby further aiding compliant mechanism design. The calculations suggest a simple way of representing the effective torque caused by a distributed load in a PRBM as a function of easily calculated model parameters.
29
Montalbano, Paul Joseph. "Multistable Shape-Shifting Surfaces (MSSSs)." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4169.
Full textAbstract:
This paper presents designs for Multistable Shape-Shifting Surfaces (MSSS) by introducing bistability into the Shape-Shifting Surface (SSS). SSSs are defined as surfaces that retain their effectiveness as a physical barrier while undergoing changes in shape. The addition of bistability to the SSS gives the surface multiple distinct positions in which it remains when shifted to, i.e. by designing bistability into a single SSS link, the SSS unit cell can change into multiple shapes, and stabilize within the resulting shape, while maintaining integrity against various forms of external assaults normal to its surface. Planar stable configurations of the unit cell include, expanded, compressed, sheared, half-compressed, and partially-compressed, resulting in the planar shapes of a large square, small square, rhombus, rectangle, and trapezoid respectively. Tiling methods were introduced which gave the ability to produce out-of-plane assemblies using planar MSSS unit cells. A five-walled rigid storage container prototype was produced that allowed for numerous stable positions and volumes. Applications for MSSSs can include size-changing vehicle beds, expandable laptop screens, deformable walls, and volume-changing rigid-storage containers. Analysis of the MSSS was done using pseudo-rigid-Body Models (PRBMs) and Finite Element Analysis (FEA) which ensured bistable characteristics before prototypes were fabricated.
30
Landon, Steven D. "Development of Deployable Wings for Small Unmanned Aerial Vehicles Using Compliant Mechanisms." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1917.pdf.
Full text
31
Liu, Chih-Hsing. "A finite element based dynamic modeling method for design analysis of flexible multibody systems." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39605.
Full textAbstract:
This thesis develops a finite element based dynamic modeling method for design and analysis of compliant mechanisms which transfer input force, displacement and energy through elastic deformations. Most published analyses have largely based on quasi-static and lump-parameter models neglecting the effects of damping, torsion, complex geometry, and nonlinearity of deformable contacts. For applications such as handling of objects by the robotic hands with multiple high-damped compliant fingers, there is a need for a dynamic model capable of analyzing the flexible multibody system. This research begins with the formulation of the explicit dynamic finite element method (FEM) which takes into account the effects of damping, complex geometry and contact nonlinearity. The numerical stability is considered by evaluating the critical time step in terms of material properties and mesh quality. A general framework incorporating explicit dynamic FEM, topology optimization, modal analysis, and damping identification has been developed. Unlike previous studies commonly focusing on geometry optimization, this research considers both geometric and operating parameters for evaluation where the dynamic performance and trajectory of the multibody motion are particularly interested. The dynamic response and contact behavior of the rotating fingers acting on the fixed and moving objects are validated by comparing against published experimental results. The effectiveness of the dynamic modeling method, which relaxes the quasi-static assumption, has been demonstrated in the analyses of developing an automated transfer system involved grasping and handling objects by the compliant robotic hands. This FEM based dynamic model offers a more realistic simulation and a better understanding of the multibody motion for improving future design. It is expected that the method presented here can be applied to a spectrum of engineering applications where flexible multibody dynamics plays a significant role.
32
Nayak, Abhilash. "L’analyse cinématique de manipulateurs parallèles et reconfigurables." Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0057/document.
Full textAbstract:
Un manipulateur parallèle à mobilité réduite a moins de six degrés de liberté et présente généralement différents types de mouvement connus sous le nom de modes d'opération. Ainsi, ce type de manipulateur peut être classifié comme reconfigurable selon sa capacité de transition entre les différents modes d'opération. Cette thèse de doctorat s'articule principalement autour de l'analyse cinématique de manipulateurs parallèles à mobilité réduite, de manipulateurs parallèles en série obtenus à partir de leur empilement en série et de mécanismes conformes conçus à partir de leurs configurations singulières à contraintes. La transformation cinématique de Study est utilisée pour dériver les équations algébriques de contraintes. Ensuite, elles sont interprétées à l'aide d'outils de géométrie algébrique pour effectuer des analyses de mobilité, de cinématique et de singularité. Les techniques de ‘‘screw theory’’ et ‘‘line geometry’’ sont utilisées à côté de l'approche algébrique au besoinA lower mobility parallel manipulator has less than six degrees of freedom and usually exhibits different motion types known as operation modes. Thus, it can be classified as reconfigurable on account of its ability to transition between different operation modes. This doctoral thesis mainly revolves around the kinematic analysis of some lower-mobility parallel manipulators, series-parallel manipulators obtained from their serial stacking and compliant mechanisms designed using their constraint singular configurations. Study's kinematic mapping is used to derive the algebraic constraint equations. They are further interpreted using algebraic geometry tools to perform mobility, kinematic and singularity analysis. Screw theory and line geometry techniques are used adjacent to algebraic approach wherever necessary
33
Winder, Brian Geoffrey. "Achieving Complex Motion with Fundamental Components for Lamina Emergent Mechanisms." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2279.pdf.
Full text
34
Klaps, J., and Andrew J. Day. "Wheel movement during braking." 2002. http://hdl.handle.net/10454/886.
Full textAbstract:
YesAn experimental study of wheel movement arising from compliance in the front suspension and steering system of a passenger car during braking is presented. Using a Kinematic and Compliance (K&C) test rig, movement of the front wheels and the suspension sub-frame, together with corresponding changes in suspension / steering geometry under simulated braking conditions, were measured and compared with dynamic measurements of the centre points of the front wheels. The resulting knowledge of front wheel deflections has enabled the causes and effects of steering drift during braking to be better understood in the design of front suspension systems for vehicle stability.
35
Wong, Pius Duc-min. "Methodology for creating human-centered robots : design and system integration of a compliant mobile base." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5433.
Full textAbstract:
Robots have growing potential to enter the daily lives of people at home, at work, and in cities, for a variety of service, care, and entertainment tasks. However, several challenges currently prevent widespread production and use of such human-centered robots. The goal of this thesis was first to help overcome one of these broad challenges: the lack of basic safety in human-robot physical interactions. Whole-body compliant control algorithms had been previously simulated that could allow safer movement of complex robots, such as humanoids, but no such robots had yet been documented to actually implement these algorithms. Therefore a wheeled humanoid robot "Dreamer" was developed to implement the algorithms and explore additional concepts in human-safe robotics. The lower mobile base part of Dreamer, dubbed "Trikey," is the focus of this work. Trikey was iteratively developed, undergoing cycles of concept generation, design, modeling, fabrication, integration, testing, and refinement. Test results showed that Trikey and Dreamer safely performed movements under whole-body compliant control, which is a novel achievement. Dreamer will be a platform for future research and education in new human-friendly traits and behaviors. Finally, this thesis attempts to address a second broad challenge to advancing the field: the lack of standard design methodology for human-centered robots. Based on the experience of building Trikey and Dreamer, a set of consistent design guidelines and metrics for the field are suggested. They account for the complex nature of such systems, which must address safety, performance, user-friendliness, and the capability for intelligent behavior.text