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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Design and Evaluation of an Underactuated Robotic Gripper for Manipulation Associated with Disaster Response

Rouleau, Michael Thomas 17 July 2015 (has links)
The following study focuses on the design and validation of an underactuated robotic gripper built for the Tactical Hazardous Operations Robot (THOR). THOR is a humanoid robot designed for use in the DARPA Robotics Challenge (DRC) and the Shipboard Autonomous Fire Fighting Robot (SAFFiR) project, both of which pertain to completing tasks associated with disaster response. The gripper was designed to accomplish a list of specific tasks outlined by the DRC and SAFFiR project. Underactuation was utilized in the design of the gripper to keep its complexity low while acquiring the level of dexterity needed to complete the required tasks. The final gripper contains two actuators, two underactuated fingers and a fixed finger resulting in four total degrees of freedom (DOF). The gripper weighs 0.68 kg and is capable of producing up to 38 N and 62 N on its proximal and distal phalanges, respectively. The gripper was put through a series of tests to validate its performance pertaining to the specific list of tasks it was designed to complete. The results of these tests show the gripper is in fact capable of completing all the necessary actions but does so within some limitations. / Master of Science
12

Hochgenaue Lagezuordnung von Mikrobauteilen durch greiferintegrierte Winkelfeinstellung

Schulz, Bertram 10 February 2009 (has links) (PDF)
Für die hochgenaue Lagezuordnung von Mikrobauteilen in Mikromontageprozessen fehlen bislang Lösungen für eine greifernahe oder greiferintegrierte Winkelfeinstellung. In der vorliegenden Arbeit werden Einflussfaktoren und Auswirkungen lokaler Restfehler auf die Lagezuordnung im Mikromontageprozess diskutiert und Strategien für eine Lagekorrektur am Mikrobauteil unmittelbar im Montageprozess abgeleitet. Im Mittelpunkt steht die Herleitung und Erforschung eines kinematischen Grundprinzips für eine greiferintegrierte Winkelfein- stellung. Eine durch Simulation des Verformungsverhaltens optimierte räumliche Biegegelenk- struktur gestattet das spielfreie Einstellen und Halten kleinster Winkellagen im Winkel- sekundenbereich um einen auf dem gegriffenen Bauteil liegenden Drehpunkt. Das Funktions- prinzip dieses Übertragungsgliedes bildet die Grundlage für einen neuartigen modular aufgebauten Präzisionsgreifertyp. Die Wirksamkeit der greiferintegrierten Winkelfein- stellung wird an einem Anlagendemonstrator zur hochgenauen Bestückung optischer Leiter- platten mit elektrisch-optischen Sende- und Empfangsmodulen nachgewiesen. Mithilfe des neu entwickelten modularen Präzisionsgreifers lassen sich Mikromontagestrategien mit prozessintegrierter bauteilindividueller Lagekorrektur umsetzen. Montagegenauigkeiten unter 5 µm können damit besser anlagentechnisch beherrscht werden, ohne dass ein zusätzliches manuelles Feinausrichten notwendig ist. / For state-of-the-art micro assembly processes with high precision alignment of micro components, solutions for a precise angle adjustment near by or integrated into a gripper are not provided yet. In this PhD thesis influencing factors and implications of local alignment failures are will be discussed and correction strategies directly in the assembling flow are will be deduced. In the central point of the PhD thesis the derivation and investigation of a novel kinematic principle for a gripper integrated angle adjustment are located. A flexure hinge structure could be designed that enables a free from backlash adjusting and fixing of angles in a size of less angular seconds whereas the center of rotation is located on the gripped part. The hinge structure was optimized by simulating the deformation behavior. The functional principle of this mechanism presents the base of a novel type of a modular precision gripper. The effectivity of the gripper integrated angle adjustment was verified at the application of high precision mounting of electric-optical circuit boards with light coupling transmitter and receiver modules. With the help of the new developed precision gripper micro assembly strategies could be realized basing on in-process alignment corrections of the individual gripped micro part. Assembly accuracies below 5 microns could be achieved plantspecific in a better way without additional manual steps for fine positioning.
13

Intelligent Gripper

Östberg, Micael, Norgren, Mikael January 2013 (has links)
The human hand is a great generic gripper as it can grasp objects of unknown shapes, weights and surfaces. Most robotic grippers in today's industry have to be custom made and tuned for each application by engineers, thus many man hours are required to get the desired behavior and repeatability. To be able to adapt some of the capabilities of the human hand into robust industrial robotic grippers would enhance their usability and ease the tuning by engineers once installed. This thesis discusses the development of a robust intelligent gripper for industrial use, based on piezo sensors which have the ability to both sense slippage and detect objects. First, an experimental sensor prototype was developed successfully using an amplification circuit and algorithms implemented in LabView. Secondly, a final prototype containing a signal board, an FPGA board, a simple gripper with linear units and more robust sensor modules where developed. The thesis further discusses which parts of the intelligent gripper that have been successfully implemented within the project time frame and which parts that needs to be further implemented, tested and improved. / Den mänskliga handen är en fantastisk universiell gripklo då den kan greppa objekt av okänd form, vikt och yta. De flesta gripklor i dagens industri måste vara specialgjorda och anpassas för varje applikation av ingenjörer och därmed behövs otaliga mantimmar för att få önskat beteende och repeterbarhet. Att kunna anpassa vissa av den mänskliga handens egenskaper till en robust industriell robotgripklo skulle utöka dess användarområde och lätta upp anpassningen för ingenjörer när den väl är installerad. Detta examensarbete diskuterar hur en robust intelligent gripklo har blivit utvecklat for industriellt bruk baserad på piezo sensorer som har förmågan att känna av glidning och initiell kontakt av objekt. Först, en experimentiell fungerande sensorprototyp utvecklades med hjälp av en förstärkningskrets och algoritmer implementerade i LabView. Därefter utvecklades en slutlig prototyp innehållandes ett signalkort, ett FPGA-kort, en enkel gripklo med linjärenheter och mer robusta sensorer. Examensarbetet tar vidare upp vilka delar som framgångsrikt blivit implementerade och vilka delar som behöver utvecklas ytterligare, testas och förbättras.
14

The application of Van der Waals forces in micro-material handling

Matope, S., Van Der Merwe, A. January 2010 (has links)
Published Article / This paper investigates the challenges of employing Van der Waals forces in micro-material handling since these forces are dominant in micro-material handling systems. The problems include the creation of a dust-free environment, accurate measurement of the micro-force, and the efficient picking and placing of micro-work pieces. The use of vacuum suction, micro-gripper's surface roughness, geometrical configuration and material type are presented as alternatives to overcome the challenges. An atomic force microscope is proposed for the accurate measurement of the Van der Waals force between the gripper and the micro-work piece.
15

Dynamic Responses of the High Speed Gear Cam Systems

Lao, Yuan-syun 18 July 2008 (has links)
Abstract The gear-cam intermittent mechanism, mainly made up by cam, the sun gear, planet gear and planetary shelf , it has been used in automatically high speed die cutting and creasing machine. The main function of die cutting and creasing machine is cutting and creasing the cardboard, and through compounding the cam motion curves, it will can control the intermittent motion of a gear-cam intermittent mechanism and improve its dynamic characteristic. The effects of gear cam profile and driving speed on the dynamic responses of a box folding and die cutting machine are studied in this work. The input driving motor¡Bgear¡Bgear-cam and output chain mechanics are included in the dynamic system. The equation of motion of the whole system in derived by employing Lagrange¡¦s equation the 4th order Runge-Kutta method is used to simulation the fine domain response of the nonlinear equation of motion. The effect of cam profile, and driving speed on the system dynamic response have been simulated and analysed in the work.
16

Linkage-based prosthetic fingertips: Analysis and testing

Ramirez, Issa A 01 June 2007 (has links)
This thesis consists of the research on linkage-based fingertips for prosthetic hands. These fingertips consists of small polycentric mechanisms attached to what would be the pulp in normal anatomical fingers. These mechanisms allow the prosthetic hand to conform to the shape of objects during grasp. The goal of these prosthetic fingertips is to maximize the functionality of the hand while minimizing the number of inputs that the user has to control. The stability of the fingertip mechanisms is analyzed using the principle of virtual work. From this analysis we are able to show that the fingertip mechanism is stable for a large range of rotation of the link and for a large range of directions on which the force is applied, and that the mechanism is indifferent to the magnitude of the force applied to it (assuming that the force does not damage/deform the mechanism). To assess if the four-bar mechanisms (fingertips) improve the grasping capabilities in robotics and prosthetics, tests were performed on prosthetic hands and robot grippers with and without the fingertips. Comparisons were made using the Southampton Hand Assessment Procedure (SHAP) protocol, which tests the differences and measures the functionality of particular types of grasp, such as power, spherical, lateral, tripod, tip and extension. In the human testing, the overall Index of Functionality (IOF) of the Hosmer hook is 66.65 and 66.21 for the hook with the fingertips. The hook with the fingertips had a better IOF in the spherical and power prehensile pattern. When the IOF is calculated for the tasks that the fingertips were used, in 10 of 11 of the tasks, the IOF is higher than using the Hosmer hook. In the robotic gripper testing, the Index of Functionality was not be calculated because the time to perform the tasks depended more on the robotic control system than on the physical characteristics of the gripper.
17

An automated system for assembling cold pressed segments

Kooiker, Johan, Roil Beto, Kashira January 2014 (has links)
During the spring of 2014, Johan Kooiker and Kashira Roil Beto, students in mechanical engineering at Linnaeus University carried out a degree project together with Husqvarna construction products Sweden AB. The topic of this project was "product development" to develop an automated system for assembling cold pressed segments. The project began with studying the current situation to get a clearer picture of the problem and finding out the requirements. The main requirements were studied and implanted in behaviour descriptions of the system. Later on ideas and concepts were generated, which then through rating and screening led to the final concept. The final concept was divided into subsystems and developed in details. The detail work included 3D cad models of unique components and selection of standard component. The final step was to build simple prototypes of the subsystems to test their functions. The prototypes of the subsystems accomplished the main requirements of the company and that led to future investment in final system.
18

Produktutveckling av gripdon / Product Development of Gripper

Xhafa, Azdren, Kalifa, Rezgar January 2016 (has links)
Examensarbetet presenterar produktutveckling av gripdon åt uppdragsgivaren Meritor HVS AB. För att få en bra förståelse av hur ett gripdon fungerar så har författarna beskrivit hur robotar hanterar gripdon. Uppdragstagaren har fått som uppdrag att utveckla ett gripdon då det befintliga gripdonet har vissa brister. Man ställs dagligen inför nya förbättringar, tekniken utvecklas fort och man strävar därför både som företagare och konstruktör mot ständiga förbättringar. En grov nulägesanalys genomfördes i inledningsfasen av arbetet för att få en helhetsförståelse av processen som gripdonen utför för att utifrån det sedan kunna jobba vidare för att utveckla ett gripdon som klarar av alla varianter av råämne som företaget arbetar med.  Då en intern benchmarking gjordes i företaget lades stor vikt på att utveckla ett nytt gripdon som kunde hantera alla varianter av kronhjulsämne som företaget ska hantera. Fördelarna blir då att man minskar ställtider på stationen samt att om nya råämne tillkommer så kommer gripdonet att kunna hantera även detta med utan att problem uppstår.  För att få fram hållbara koncept så genererade författarna först idéer med hjälp av en tankekarta för att få en bred vetskap om problemet och kunna inrikta sig på att få fram det bästa möjliga konceptet att arbeta med. För att bevisa att de framtagna koncepten kan hantera alla varianter av råämne så har författarna genomfört beräkningar som visar teoretiskt att konceptförslagen är hållbara. koncepterna som presenterats i projektet har gjorts av CAD- programmet Creo Parametric.  Resultatet av examensarbetet visar att konceptet med två parallella hydraulikcylindrar uppfyller kraven som författarna har ställts inför, och det har även visat en utvecklad produktframtagning som går att implementera i företaget. / The thesis presents the product of grippers for the client Meritor HVS AB. To get a good understanding of how a gripper works, the authors described how robots handling grippers. The contractor has been given the mandate to develop a gripper when the existing gripper has some shortcomings. It is daily facing new improvements, technology develops fast and the aim is therefore both business and designer for continuous improvement. A situation analysis conducted in the initial phase of our work was made to get an overall understanding of the process to be able to continue working to develop a gripper that can handle all varieties of raw material as the company works with. When an internal benchmarking was done in the company placed a strong emphasis on developing a new gripper that could handle all variants of the crown wheel substance that the company must manage. The benefits will then reducing setup time at the station and that of new raw material will then gripper to handle too with without problems. In order to produce a sustainable concept that generated the authors first ideas using a mind map to get a broad knowledge of the problem and to focus on getting the best possible concept to work with. To prove that the developed concepts can handle all varieties of raw material, the authors performed calculations showing that the theoretical concept proposals is sustainable. The concepts presented in the project has been done by the CAD program Creo Parametric. The results of the thesis show that the concept of two parallel hydraulic cylinders meets the requirements we had, and it has also shown a developed product realization that can be implemented in the company.
19

Automated Production of Air to Air Heat Exchangers : Robot Cell Design and Simulation

Brusén, Niklas, Kristoffersson, Jon January 2017 (has links)
The aim of this thesis was to describe how a manual assembly process of polycarbonate sheets for heat exchangers can be automated with an industrial robot. The objectives were to design suitable robot cell concepts and simulate them to describe how the automated process could be done and to present which machines and equipment that could be used. Additionally, productivity rates and investment costs was to be calculated.The project started with a situation assessment and a literature review. Experts and suppliers of robotic equipment were consulted, and the results served as a basis for the concept generation process. Several concept ideas were evaluated, and three ideas using adhesive for the assembly were chosen for further studies and simulation. Existing products and machines were used in the designs when possible. By modeling and simulating the cells in simulation software, feasible cell designs was created, and cycle times were measured.The three proposed solutions all utilize an industrial robot, a vacuum gripper and adhesive as the assembly method. Two of the concepts has the robot attending different adhesive dispensing machines; one gantry and one conveyor. In the third concept, the robot applies the adhesive. The cell design that achieved the lowest cycle time in the simulations was the conveyor concept, with a cycle time of 21 seconds per sheet. The conclusion of the study is that investing in a robot cell would increase productivity. / Syftet med detta arbete var att designa en robotcell anpassad för tillverkning av värmeväxlarpaket i moduler. Målet var att besvara hur tillverkningen av värmeväxlare kan automatiseras samt vilken robot och övriga verktyg och maskiner som kan användas. Vidare skulle den möjliga produktionstakten och investeringskostnaden för designförslagen beräknas. Arbetet inleddes med en nulägesanalys och en litteraturstudie. Ett flertal experter och leverantörer inom automationsområdet konsulterades. Resultaten från detta låg till grund för en konceptgenereringsprocess i vilken ett flertal designidéer togs fram. Tre av dessa designförslag valdes ut för vidare studier och simulering. Genom att modellera och simulera robotcellerna kunde de utformas realistiskt och möjliga cykeltider beräknas. De tre designförslagen använder alla en robotarm, ett vakuumgripdon samt lim som metod för monteringen. Två av koncepten består av en medelstor robotarm som betjänar en limappliceringsmaskin. I ena konceptet är det en kartesisk robot med limbord som används för limappliceringen, i det andra är det ett transportband som för plastskivan under ett antal limpistoler. Det tredje designförslaget låter en större robot, utrustad med verktygsväxlare, utföra alla moment i processen genom att den byter verktyg mellan vakuumgripdon och limpistol. Det koncept som uppnådde den lägsta cykeltiden i simuleringarna var lösningen med rullbandet, med en cykeltid på 21 sekunder per skiva. Studiens slutsats är att en investering i en robotcell skulle leda till ökad produktivitet jämfört med manuell produktion.
20

Design, Modeling, and Evaluation of Soft Poly-Limbs: Toward a New Paradigm of Wearable Continuum Robotic Manipulation for Daily Living Tasks

January 2020 (has links)
abstract: The term Poly-Limb stems from the rare birth defect syndrome, called Polymelia. Although Poly-Limbs in nature have often been nonfunctional, humans have had the fascination of functional Poly-Limbs. Science fiction has led us to believe that having Poly-Limbs leads to augmented manipulation abilities and higher work efficiency. To bring this to life however, requires a synergistic combination between robot manipulation and wearable robotics. Where traditional robots feature precision and speed in constrained environments, the emerging field of soft robotics feature robots that are inherently compliant, lightweight, and cost effective. These features highlight the applicability of soft robotic systems to design personal, collaborative, and wearable systems such as the Soft Poly-Limb. This dissertation presents the design and development of three actuator classes, made from various soft materials, such as elastomers and fabrics. These materials are initially studied and characterized, leading to actuators capable of various motion capabilities, like bending, twisting, extending, and contracting. These actuators are modeled and optimized, using computational models, in order to achieve the desired articulation and payload capabilities. Using these soft actuators, modular integrated designs are created for functional tasks that require larger degrees of freedom. This work focuses on the development, modeling, and evaluation of these soft robot prototypes. In the first steps to understand whether humans have the capability of collaborating with a wearable Soft Poly-Limb, multiple versions of the Soft Poly-Limb are developed for assisting daily living tasks. The system is evaluated not only for performance, but also for safety, customizability, and modularity. Efforts were also made to monitor the position and orientation of the Soft Poly-Limbs components through embedded soft sensors and first steps were taken in developing self-powered compo-nents to bring the system out into the world. This work has pushed the boundaries of developing high powered-to-weight soft manipulators that can interact side-by-side with a human user and builds the foundation upon which researchers can investigate whether the brain can support additional limbs and whether these systems can truly allow users to augment their manipulation capabilities to improve their daily lives. / Dissertation/Thesis / Doctoral Dissertation Systems Engineering 2020

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