Dissertations / Theses on the topic 'Robot Gripper'

In surgery, suturing is the use of needle and thread to join cut and/or damaged anatomical structures together. This repair strategy is highly versatile and is universal for all types of surgery as the goal is to restore, repair or improve function and/or appearance. The needles are almost always curved in shape, and it is handled and maneuvered by surgeons with a special tool called: needle driver. The versatility of this setup has proven its worth over time as needle drivers are one of the indispensable instruments in all types of surgery. We are entering a future where robots can be programmed to execute tasks with much higher level of precision and speed compared to humans. Medical robotics in surgery has gained ground over the past decades due to promising clinical results. A straightforward step in this direction would be to create a solution that enables the robot to grip needle driver. The purpose of this study was to develop a gripper tool that enables a collaborative robot to perform suturing with one of the most common types of needle drivers used in surgery. The Double Diamond design framework was employed. The selected content in the predefined four phases were: 1) Discover: Observation, MoSCoW Prioritization, Brainstorming, Choosing a Sample, Fast Visualisation, 2) Define: Assessment criteria, 3) Develop: Physical prototyping 4) Deliver: Final testing and Evaluation. In the first phase, Discover, clinical and technical demands were formulated. In the second phase, Define, numerous design ideas were generated and drafted on paper whereof the one with highest assessment score was chosen for physical prototyping. In phase three, Develop, the selected design idea was modelled in cardboard, clay and silicon, and 3D printed. Multiple design iterations were guided by feedback from clinical and technical experts and resulted in a final prototype design that was accepted by the experts. In phase four, Deliver, the final prototype was subjected to final testing and evaluation. Observation of five live and one video recording of surgical procedures on real patients were made. The insights gained were confirmed with the lead and co-surgeons of each procedure and were summarized in 24 clinically important observations relevant for the gripper tool design. Careful analysis of the previously designed gripper tool, live observation of the robot’s motion pattern and range, and interview with robotic engineer were summarized in ten technically important observations. The observations were then used to formulate the clinical and technical demands that the gripper tool design aims to fulfill, followed by prioritizing the demands and design features according by MoSCoW method and brainstorming on how to improve previous gripper tool design. To limit the scope of the design challenge, one of the five types of needle drivers used in pediatric heart surgery in Lund was selected in the method Choosing a Sample. To further characterize the clinical and technical demands, a test bench was set up to Define and measure force vectors applied on the needle driver when held by a surgeon during suturing. The radial forces vectors in six directions perpendicular to the tip of the needle driver ranged from 1.6 N to 3.8 N. The axial force along the length of the needle driver was 7.6 N towards the tip and 8.4 N towards the back end. The clockwise and counterclockwise torque along the length axis of the needle driver was 0.2 Nm and 0.18 Nm, respectively. The set of defined demands were sufficient to sketch numerous ideas of gripper tool designs according to the Fast Visualization method. These designs were then used in the Define phase to communicate the design ideas with surgeons, robotic and product development engineers. The most promising idea was advanced to the Develop phase where physical prototypes were produced in cardboard, clay and silicon and 3D printed. Inadequacies were found during design feedback with interviews and testing together with clinical and technical experts, and design actions were taken to arrive at the final prototype. The final prototype was brought into the Deliver phase for final testing and evaluation. The gripper tool could handle lager force loads than the human surgeon in all the stability tests. However, deflection of the needle driver occurred with the gripper tool unlike when the surgeon was subject to stability testing. One pediatric heart surgeon and one robotic engineer was asked to generate a composite score of fulfillment rate from 1–5, where 1 is bad, 3 satisfactory, and 5 excellent after final testing of the gripper tool was carried out. The final prototype of the gripper tool fulfills all clinical and technical demands at the level of 4, and 3–5, respectively. In conclusion, the design methodology used in this study was useful in the development of a gripper tool design that respects both clinical and technical demands. This suggest that the methodology may be used in similar setting of design challenges in the field between medical and technical innovation. The gripper tool fulfilled the demands, although further refinement in the choice of material, further testing and investigation of regulatory aspects are required before it can be implemented in the operating room.
Vid operation är suturering användningen av nål och tråd för att sammanfoga snittad och/eller skadade anatomiska strukturer. Denna reparationsstrategi är mycket mångsidig och universell för alla typer av kirurgi eftersom målet är att återställa reparera eller förbättra funktion och/eller anatomisk defekt. Nålarna är nästan alltid krökta i sin form och de hanteras och manövreras av kirurgerna med ett speciellt verktyg som kallas: nålförare. Mångsidigheten i denna uppställning har visat sig över tid eftersom nålförare är ett av de oumbärliga instrumenten vid alla typer av operationer. Vi går in i en framtid där robotar kan programmeras för att utföra uppgifter med mycket högre precision och hastighet jämfört med människor. Medicinska robotar inom kirurgi har varit på frammarsch senaste årtionden på grund av goda kliniska resultat. Ett steg i denna riktning skulle vara att skapa en lösning som gör det möjligt för en robot att greppa nålföraren. Syftet med denna studie var att utveckla ett gripdon som möjliggör för en kollaborativ robot att utföra suturering med hjälp av en av de vanligaste typerna av nålförare som används vid operation. Design metodiken Double Diamond användes för att beskriva design processensen. Det valda metoderna i de fyra för definierade faser var: 1) Discover: Observation, MoSCoW Prioritization, Brainstorming, Choosing a Sample, Fast Vissualization, 2) Define: Assessment criteria, 3) Develop: Physical Prototyping, 4) Deliver: Final testing and Evaluation. I första fasen, Discover, formulerades kliniska och tekniska krav. I den andra fasen, Define, definierades flera designidéer som skissades på papper, varav den med den högsta poängen valdes i Assessment criteria. I fas tre, Develop, modellerades den valda designidén i kartong, lera och silikon samt 3D-printades. Flera designiterationer gjordes baserat på feedback från kliniska och tekniska experter vilket resulterade i en slutlig prototypdesign som godkändes av experterna. I fas fyra, Deliver, testades och utvärderades den slutliga prototypen. Observation av fem realtids och en videoinspelning av kirurgiska ingrepp på riktiga patienter gjordes. Insikterna som gjordes bekräftades med kirurgerna som genomförde operationen och sammanfattades i 24 kliniskt viktiga observationer som var relevanta för gripdon designen. Noggrann realtids observation av robotens rörelsemönster samt analys av det tidigare utformade gripdonen och intervju med en robotingenjör sammanfattades i tio tekniskt viktiga observationer. Observationerna användes för att formulera kliniska och tekniska krav som gripdons designen strävar efter att uppfylla, följt av prioritering av kraven och designegenskaper enligt MoSCoW-metoden och brainstorming kring hur tidigare gripdons design kan förbättras. För att begränsa designutmaningens omfattning valdes en av de fem typer av nålförare som används vid barnhjärtkirurgi i Lund genom metoden Chossing a sample. För att ytterligare karakterisera de kliniska och tekniska kraven upprättades en testbänk för att definiera och mäta kraftvektorer som appliceras på nålföraren när den hålls av en kirurg under suturering. De radiella krafterna i sex riktningar vinkelrätt mot nålförarens spets varierade från 1,6 N till 3,8 N. Den axiella kraften längs nålförarens längd var 7,6 N mot spetsen och 8,4 N mot bakänden. Medurs och moturs vridmoment längs nålförarens längdaxel var 0,2 Nm respektive 0,18 Nm. Dom definierade kraven låg till grund för skisser av flertal gripdondesign idéer enligt Fast Visualization. Dessa skisser användes sedan i Define fasen för att kommunicera designidéer med kirurger samt robot- och produktutvecklingsingenjörer. Den mest lovande idén togs till Develop fasen där fysiska prototyper togs fram i kartong, lera och silikon samt genom 3D-printning. Förbättringspunkter hittades under testning och återkoppling med intervjuer tillsammans med kliniska och tekniska experter. Designåtgärder baserat på återkopplingen gjordes för att komma fram till den slutliga prototypen. Slutlig testning och utvärdering av den slutliga prototypen genomfördes i Deliver fasen. Gripdons designen kunde hantera större belastningar än den mänskliga kirurgen i alla stabilitetstester. Böjning av nålföraren uppstod dock i testerna med gripverktyget till skillnad från testerna med kirurgen var föremål för stabilitetsprovning. En barnhjärtkirurg och en robotingenjör poängsatte uppfyllnadsgrad av de kliniska respektive tekniska kraven efter att slutlig testning av gripdonet utförts. Uppfyllnadsgraden poängsattes från 1–5 där 1 var dålig, 3 tillfredsställande och 5 utmärkt. Gripdonets slutliga prototyp uppfyller alla kliniska och tekniska krav på nivå 4 respektive 3–5. Designmetodiken som användes i denna studie var användbar för utvecklingen av gripdon som uppfyller både de kliniska och tekniska kraven. Detta tyder på att denna metod kan användas i liknande designutmaningar inom området mellan medicinsk och teknisk innovation. Gripdonet uppfyllde kraven även om ytterligare förfining i materialvalet, ytterligare testning och undersökning av regulatoriska aspekter krävs innan den kan användas under riktiga operationer i operationssalen.

A novel robot gripper control system is presented which uses PVDF piezoelectric sensors to actively damp exerted force. By using a low-input-resistance amplifier to sense the current developed by the PVDF sensor, an output proportional to the rate of change of the force exerted by the gripper is obtained. The signals from the PVDF sensor and a strain gauge force sensor are arranged in a proportional and derivative (PD) control system for the control of force. The control system was tested on an instrumented Rhino XR-1 manipulator hand. The capabilities of the control system are analyzed analytically, and verified experimentally. The results for this particular gripper indicate that as much as 900% improvement in force step response rise time, and 300% reduction in overshoot are possible by inclusion of the PVDF sensor.
Master of Engineering

In this thesis study, a two-fingered gripper and a four-fingered multipurpose gripper are developed and manufactured. In addition to development of robotic hands, computer control hardware and software are also developed for computer control of both hands. The two-fingered gripper is designed for a specially defined pick and place operation. Its task is to pick a cylindrical work piece and place it in the appropriate position in a flexible manufacturing cell. Pneumatic actuator is used for power generation and mechanical links are used for power transmission. Fourfingered gripper is designed as a multipurpose gripper. The task is not predefined for this gripper, so, human hand and previous dexterous hands are taken as model during design. It consists of 3 fingers and a thumb. It has 1 degree of freedom for every finger and thumb. Pneumatic actuators are also used for this gripper. Rope and pulley system is used for the power transmission mechanism. Structures of both hands are manufactured from 5083 series aluminum. Gripping force can be controlled by the pressure regulator of the pneumatic system for both hands. Computer software is developed for the control of open and close motion of the fingers. Also, a motion control card is designed and manufactured for control of the pneumatic valves.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 47-49).
In this work, an underactuated robot gripper was designed to meet specifications for strength, cost, and ease of manufacturing with Open-Source distribution in mind. The specifications emerged from a need for inexpensive grippers that can be used on robots that help people brace and balance. The structure and transmission of the gripper is designed to bear 150 lbs-force of static tensile and compressive loads. Gripping forces that exceed the static actuator force output are achieved by a novel method of clamping the main drive tendon by detecting dynamic overshoot and applying a self-helping cable brake, relieving the main drive actuator. The geometry, stiffness, and behavior of the gripper was designed using mathematical models and tools developed in prior art for the optimal design of underactuated hands. Apart from the actuators and waterjet machining services, the materials for the gripper can be purchased in one McMaster-Carr order. The entire structure can be cut from a single sheet of 1/16" 2024 aluminum and requires one operation on a waterjet machine, which can be found in many machine shops or through online machining services. It is the intention of the author to release the design files as Open-Source in order to allow robot researchers, engineers, and enthusiasts to use this gripper in their own work.
by Daniel Jesus Gonzalez.
S.B.

Autonomous mobile robots are on the rise and are to be expected on the market in about 5-10 years. Several challenges need to be solved for this to happen, and the most crucial ones are to develop versatile and safe robots. The Get a Grip robot is a dynamic force adjustment gripper using inputs from two different sensory systems. The construction of the robot consists of two parallel gripper plates moved by a rack and pinion gear attached to a direct current (DC) motor. Embedded into one of the plates is a Force Sensitive Resistor (FSR) for input of the gripper’s exerted force. Mounted to the other plate is a self constructed Slip sensor used for measuring the occurrence of slip and slip rate. A surrounding crane for mounting of the gripper and lifting was also constructed. The idea of this bachelor’s thesis project is to enable lifting of objects with unknown weight without the gripper exerting more force than necessary. This is something that will be useful in both industrial applications and in household robots in the future. In order to realize the concept two different methods for calculating the gripper’s applied force were tested, one using motor current and the other using a FSR sensor. Through testing it was concluded that the FSR sensor was the method giving better accuracy and consistency. Proportional–Integral–Derivative (PID) controllers were then tested for both setting force references for the gripper using the Slip sensor as input, and controlling the exerted force in the gripper using the FSR as input. The results led to two PID controllers thought to be sufficient as starting points for further testing of the complete system.
Mobila autonoma robotar förväntas vara på marknaden inom de närmaste 5-10 åren. För att det här ska ske är det många utmaningar som behöver lösas och de mest kritiska är att utveckla mångsidiga och säkra robotar. Get a Grip-roboten är en dynamisk kraftanpassande robotklo som tar insignaler från två olika sensorsystem. Konstruktionen består av två parallella plattor som förflyttas av kuggstänger och kugghjul drivna av en DC motor. Inbyggt i en av kloplattorna finns en tryckkänslig kraftsensor (FSR) monterad för att registrera kraften som klon genererar. På den andra kloplattan sitter en egenkonstruerad glidsensor som registrerar om glidning sker och själva glidhastighet. En kran för att montera klon och lyfta den konstruerades även. Idén bakom detta kandidatexamens projektet är att klon ska kunna lyfta ett objekt med okänd vikt utan att använda mer kraft än nödvändigt. Det är något som kommer vara användbart både vid industriella tillämpningar och hos husållsrobotar i framtiden. För att realisera konceptet testades två olika metoder för att estimera kraften klon genererar, den första genom motorströmmen och den andra genom en FSR sensor. Tester genomfördes för båda metoderna och slutsatsen blev att FSR sensorn gav bäst noggrannhet och var mest konsekvent. PID-regulatorn, för bestämning av kraftreferens, med insignal från glidsensorn och PID-regulatorn, för genererad klokraft, med insignal från FSR:n testades separat. Resultatet blev två PID-regulatorer som ansågs tillräckliga för fortsätta tester med båda regulatorerna tillsammans.

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

This diploma thesis deals with the design of robot machining of three-dimensional objects. Used method is Part to tool, in which robot holds the part in its gripper and with stacionary clamped mill, machines the part. Overally three parts for machining are designed, everyone of them shows the different style of machining. Every machining operations are described in details. For their creation was used program Mastercam. Furthermore is described transfer of the data for industrial robot using program Robotmaster and recomanded algorithm for creation of similar tasks. The design of simplified workplace for demonstrative show of the milling of all the parts is also solved.

Automation of the industrial transformer core assembly process is highly desirable. A survey undertaken by the author however, revealed that due to the high cost of existing fully automated systems, Australian manufacturers producing low to medium transformer volumes continue to maintain a manual construction approach. The conceptual design of a cost-effective automation system for core assembly from pre-cut lamination stacks was consequently undertaken. The major hurdle for automating the existing manual process was identified as the difficulty in reliably handling and accurately positioning the constituent core laminations, which number in their thousands, during transformer core construction. Technical evaluation of the proposed pick-and-place core assembly system, incorporating two mobile robots bearing a common gripper, is presented herein to address these requirements. A unique robotic gripper, having the capability to selectively pick a given number of steel laminations (typically two or three) concurrently from a stack, has the potential to significantly increase productivity. The only available avenue for picking multiple laminations was deemed to be a gripper based on magnetism. Closed form analytical and finite element models for an electromagnet-stack system were contrived and their force distributions obtained. The theoretical findings were validated by experiment using a specially constructed prototype. Critical parameters for reliably lifting the required number of laminations were identified and a full scale electromagnet, that overcame inherent suction forces present in the stack during picking, was subsequently developed. A mechanical docking arrangement is envisaged that will ensure precise lamination placement. Owing to the grippers unwieldy length however, conventional robots cannot be used for assembling larger cores. Two wheeled mobile robots (WMRs) compliantly coupled to either end of the gripper could be considered although a review of the current literature revealed the absence of a suitable controller. Dynamic modelling for a single WMR was therefore undertaken and later expanded upon for the dual WMR system conceived. Nonlinear adaptive controllers for both WMR systems were developed and subsequently investigated via simulation. Neglecting the systems dynamics resulted in analogous, simplified kinematic control schemes, that were verified experimentally using prototypes. Additional cooperative control laws ensuring the synchronisation of the two robots were also implemented on the prototype system.

Line following robots are a practical mechatronics solution in a world that is becoming more and more automated. With added gripping and lifting abilities, a very versatile robot can be created. The goal of this thesis was to create a prototype that could navigate a black line using infrared sensors whilst gripping and lifting a package. A working prototype was built and five different sensor placements were evaluated to assess which was optimal for linefollowing. The results showed that too close placement of the sensors led to a less stable system while more distance between the sensors made a faster and more accurate system.
Linjeföljarrobotar är en praktisk mekatroniklösning i en värld som blir allt mer automatiserad. Med grepp- och lyftförmågor kan en väldigt anpassningsbar robot skapas. Målet med detta arbete var att skapa en prototyp som kunde navigera en svart linje med hjälp av infraröda sensorer medan den greppade och lyfte ett paket. En fungerande prototyp byggdes och fem olika sensorplaceringar utvärderades för att bedöma vilken som var optimal för att följa en linje. Resultatet visade att för nära placering av sensorerna skapade instabilitet. Ett större avstånd mellan sensorerna var att föredra då detta gav ett snabbare och stabilare system.

Nel presente elaborato è stato valutato l’inserimento di robot commerciali per il caricamento di materiali da processare da macchine automatiche del tè. Sono state affrontate sia valutazioni di tipo progettuale che di tipo economico al fine di poter ottenere e confrontare soluzioni che fossero concretamente realizzabili, in linea con le normative vigenti ed economicamente vantaggiose rispetto alle convenzionali soluzioni senza robot. L’elevato numero di aspetti da considerare ha richiesto lo studio e l’integrazione di campi tematici differenti.

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.

La presente tesis comprende el diseño mecánico de un gripper (garra o manipulador) para brazo robot para el paletizado de cajas de 20kg y pallets de 25kg. La función principal del gripper es sujetar y descargar pallets y cajas por separado. La función del conjunto es transportar un pallet proveniente de un conjunto de pallets apilados hacia la zona de paletizado. Después, transportar cajas de una en una, provenientes de una faja transportadora, hacia la zona de paletizado. En esta zona, se descargan las cajas sobre el pallet formando un arreglo. El diseño óptimo fue el resultado de un proceso de selección dentro de las alternativas de solución planteadas, las cuales, se evaluaron tanto técnica como económicamente hasta llegar a la mejor opción que cumpla con las exigencias de diseño. La metodología utilizada en el presente diseño está basada en las recomendaciones de la Asociación Alemana de Ingenieros (VDI 2221). Posteriormente, se calculan, dimensionan y seleccionan los elementos principales que permitan al gripper la sujeción de cajas y de pallets. Dentro del cálculo, se experimentó en el laboratorio de manufactura de la PUCP, la deformación que sufre la caja al aplicarle la fuerza de sujeción, concluyéndose así que la caja no sufre daños en la manipulación. Además, se presentan los planos de ensamble y despiece del gripper así como los materiales necesarios para su construcción. Finalmente, se presenta la cotización para la fabricación de este, obteniéndose un costo aproximado de S/.12 279,6 Nuevos Soles, costo que podría disminuir optimizando formas constructivas y materiales utilizados.
Tesis

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.

This diploma thesis deals with the design of a virtual model of a robotic workplace. Robot and robotic workplaces are researched. Further, the design and safety phases of these workplaces are discussed. A conceptual model of the robotic workplace with robot IRB 4400/60 is designed, which is placed in the machine laboratory C1 of the Institute of Production Machines, Systems and Robotics at the Faculty of Mechanical Engineering of the Brno University of Technology. The virtual model is created in Process Simulate 13.0. It is designed to manipulate the dice, weld and operate the vertical machine tool.

Le travail présenté dans ce mémoire concerne le développement d’un système universel de manipulation de matériaux textiles souples. Il s’agit d’une pince de manipulation universelle qui se compose de trois techniques de manipulation, technique de vide, technique d’intrusion, technique de pincement. Cette pince universelle a été développée pour manipuler une surface textile de 100 x 100 mm². Les buts de cette pince sont les suivants: Acquérir une seule couche à partir d'un empilement de tissus.Tenir une seule couche, la transférer et la manipuler jusqu’au poste suivant.La technique de vide est la première technique développée dans notre recherche, elle se compose des organes de préhension qui sont « trois ventouses pneumatiques » dont les matériaux varient en fonction des matériaux textiles à manipuler, trois compensateurs de hauteur pour fixer les ventouses pneumatique et d'un générateur de vide pour créer le vide nécessaire grâce à un régulateur de pression. Les trois ventouses pneumatiques sont placées précisément sur les têtes d’un triangle équilatéral, au-dessus de la pièce textile. La technique d’intrusion est la deuxième technique développée dans notre recherche, cette technique est constituée de deux parties principales: Une partie qui donne le mouvement et l'actionnement des organes de préhension.Une partie de préhension qui contient des éléments de préhension qui sont des aiguilles.L’ensemble est commandé, au travers de vérins, par de l’air comprimée. La technique de pincement est la troisième technique développée dans notre recherche, elle comprend des organes de serrage opposés qui sont à mis en mouvement de façon alternative par deux vérins pneumatiques Deux types de validation des éléments constituant de la pince de préhension développée ont été réalisés avec succès, une validation statique en utilisant un support de fixation, une validation dynamique en utilisant un bras de robot. Pendant la validation statique, nous avons trouvé que la technique de vide fonctionnait très bien avec les matériaux imperméables à l’air et avec des matériaux ayant une porosité inférieure à 80% et/ou une perméabilité inférieure à 1500 L/m²/s sous 200 Pa.Pour les matériaux textiles ayant une porosité supérieure à 80% et/ou d’une perméabilité supérieure à 1500 L/m²/s sous 200 Pa, la consommation importante d’air comprimé interdit l’utilisation de cette technique et la force réelle d’attraction dépendant des propriétés du matériau manipulé suivant :La porosité, La perméabilité à l’air, La masse surfacique de matériau. Concernant la technique d’intrusion, nous trouvé que cette technique permet une manipulation efficace des matériaux textiles qui sont difficiles à manipuler par la technique de vide. Elle fonctionne très bien pour des matériaux perméables à l’air (tissus d’armure toile, tricots) alors qu’elle endommage les matériaux imperméables. Les risques liés à cette technique est le prélèvement de plusieurs couches à la fois si la profondeur de perçages des aiguilles n’est pas contrôlé précisément. Pendant la validation statique de la technique de pincement, nous avons trouvé que cette technique ne fonctionne pas bien seule.Pour résoudre ce problème, nous avons utilisé, la combinaison de deux technologies La technique d’intrusion technique La technique de pincement Et La technique de vide. La technique de pincement Les résultats trouvés pendant la validation de cette technique sont les suivants : la technologie de vide associée à la technique de serrage est la combinaison la plus efficace et la plus fiable, par contre un des inconvénients de cette technique est le contrôle de la force de serrage afin d’éviter l’endommagement de la surface de matériau manipulé. [...]
The work presented in this thesis concerns the development of a universal system for handling flexible textile materials. This is a universal gripper for manipulation, which consists of three technologies of manipulations, vacuum technology, intrusion technology, pinch technology. This new universal system was developed to handle a pieces of cut fabrics a square shape which had the dimensions of 100 mm×100 mm. The aims of this gripper are: Acquiring a single ply from a stack of woven fabrics Acquiring a single ply, handling and transfer it to the next station.The vacuum technology is the first technique developed in our research, it consists of a grippers which are « three pneumatic flat suction pads with stops » whose materials vary according to the manipulate textile materials, three level compensators for fixing the penumatic flat suction pads and a pneumatic vacuum generator to create the necessary vacuum thanks to a pressure regulator. The three pneumatic flat suction pads are precisely placed on the heads of an equilateral triangle, above the textile piece.The intrusion technology is the second technique developed in our research; this technique consists of two main parts: A party that gives movement and actuation of the gripper A party for gripping witch include the gripping elements that are needles The both parties are controlled, through a penumatic cylinder, by compressed air.The pinch technology is the third technique developed in our research; it comprises clamping grippers which are placed oppositely to moving alternately by two pneumatic cylinders.Two types of validation of the elements constituting of the gripper developed are performed, static validation by using a bracket, dynamic validation by using the robot arm.During the validation static, we found that the vacuum technology performs well for non-permeable materials and with the materials whose their porosity less of the 80 % and their air permeability less than 1500 L/m²/s under 200 pa.For the materials textiles whose their porosity more than 80 % and their permeability more than 1500 L/m²/s under 200 pa, the high consumption of compressed air prohibits the use of this technique, and the real force of attraction dependent on the following material manipulated properties: • Porosity of the material• Air permeability• Weight of the material.Concerning the intrusion technique, we found that this technique allows realizing an effective handling of textile materials which are difficult to handle by the vacuum technique. It performs very well for air permeable materials (plain weave fabrics, knitted fabrics), while damaging waterproof materials. The risk associated with this technique is the manipulation multiplies of the layers at a time if the depth of the piercing of the needles is not precisely controlled.During the static validation of the pinch technique, we found that this technique does not function well alone. To solve this problem, we used, the combination of two technologies: Intrusion technology Pinch technology and Vacuum technology Pinch technologyThe results found during the validation of this technique are: the vacuum technology associated with the pinch technology is the most effective combination and more reliable, by against one disadvantage of this technique is the control of the clamping forces to prevent the damage of the material surface manipulated.For the dynamic validation of the gripper developed, we used the robot manipulation STÄUBLI. We fixed the gripper on the end of the arm of robot and after setting it, we varied the speed of manipulation to determine the limits of the manipulation by each technology.These validation procedures have in evidence the limits of our new gripper in terms of capacity of the gripping, consumption of the compressed air, characteristics and limitations of the flexible materials handled. [...]

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.

Thesis is dealing with the creation of robotic worplace and its periphery. The paper is discrabing the robotic function and kinematics. The practical part of the paper shows several types of suggested robotic workplaces followed by solution processing of one selected type, where technical documentation and the calculation of production is made. The end of the paper shows economical and technological evaluation of the selected type of workplace including the price returns.

[EN] The primary handling of food with robots calls for the development of new manipulation devices, especially when products are easily damaged and have a wide range of shapes and textures. These difficulties are even greater in the agricultural industry because the quality of the products is also checked during the manual handling process. This PhD dissertation provides solutions to these issues and helps to further introduce robotics into the handling of food. Several methods for handling food are included and analyzed, and specific solutions are proposed and then validated with prototypes. The research focuses on devices capable of adapting themselves to the shapes of the products without increasing the complexity of the mechanism. After analyzing several different solutions, the method chosen involves the use of under-actuated mechanisms, compliant mechanisms and fingers with pads filled with granular fluids. These fluids can behave as quasi-liquids or quasi-solids due to the jamming transition, which provides a soft initial grasp and can support high stresses during fast movements performed by the robot. The additive manufacturing process provides an opportunity to develop robot grippers that are lighter, simpler, more flexible and cheaper. By using this process elastic mechanisms are manufactured in a single part, which are equivalent to mechanisms with several rigid parts connected by joints. Laser sintering is employed to produce pneumatic actuators, with different types of motions, based on the elastic properties of the materials used in this manufacturing process. As a result, the systems can be simplified to achieve grippers, with several fingers, that are produced as a single part. In order to estimate the freshness and quality of agricultural products while they are being grasped, accelerometers are added to the fingers of several grippers. Accelerometers are economical and act as intrinsic tactile sensors. They can be easily embedded, thereby reducing the risk of getting damaged due to contact with the product, and allow each of the grasping phases to be identified. To achieve good performance of the accelerometers, a specific process is defined for the robot gripper, which touches the products a few times. In addition, several gripper prototypes are manufactured with diverse under-actuated mechanisms, jamming systems, and a new program that processes the signals from the accelerometers using different procedures in order to obtain parameters that can be used to estimate the quality of products. These parameters are correlated with data from destructive tests that are commonly used as a reference. The best performance of the accelerometers is achieved when the finger employs a granular fluid, a correlation coefficient of 0.937 being accomplished for the ripeness of mangoes and 0.872 for the firmness of eggplants.
[ES] La manipulación primaria de alimentos con robots precisa del desarrollo de nuevos sistemas de manipulación especialmente cuando los productos son sensibles al daño y presentan una amplia variabilidad de formas y texturas. En el sector agroalimentario las dificultades son aún mayores ya que la manipulación manual sirve además para inspeccionar los productos durante el proceso. Está tesis aporta soluciones a estos problemas facilitando la incorporación de la robótica. En la tesis se recopilan y analizan diversas soluciones para poder manipular alimentos proponiendo soluciones concretas que luego son validadas con prototipos. La investigación se centra en aquellos sistemas que son capaces de auto adaptarse a las formas de los productos sin incrementar la complejidad del mecanismo. Tras analizar diversas técnicas se propone el uso de mecanismos infra-actuados, mecanismos flexibles y dedos con fluidos granulares que, al estar encerrados dentro de una membrana, se comportan como cuasi-líquidos o cuasi-sólidos gracias a la transición jamming, permitiendo un agarre inicial suave y la posibilidad de transmitir esfuerzos elevados durante los movimientos del robot. En la búsqueda de garras más ligeras, sencillas, flexibles y económicas se aprovecha la oportunidad que brinda la tecnología de fabricación aditiva de material. Gracias a este proceso se fabrican mecanismos flexibles realizados en una única pieza y que equivalen a mecanismos de garras realizados con varias piezas rígidas unidos por articulaciones. Mediante el sinterizado por láser, se fabrican actuadores neumáticos, con diversos tipos de movimiento, basados en la flexibilidad del material empleado en su fabricación. En conjunto se simplifican los sistemas llegando a realizar garras flexibles de varios dedos fabricadas en una única pieza. Para evaluar la calidad y frescura de los productos agroalimentarios durante el agarre se emplean acelerómetros localizados en los dedos de varias garras. Los acelerómetros son económicos y se comportan como sensores táctiles intrínsecos, están fuera del contacto directo con el producto evitando desgastes por contacto y permiten identificar las distintas fases de agarre. Para lograr esto se desarrolla un proceso específico del robot con la garra, que palpa varias veces el producto. Se fabrican diversos tipos de garra con distintas tecnologías de mecanismos infra-actuados y sistemas jamming y se programa un algoritmo original de procesado de señal que con diversas técnicas es capaz de extraer parámetros de los acelerómetros que sirven para evaluar la calidad de los productos. Estos parámetros son correlacionados con los datos de ensayos destructivos que son habitualmente empleados como referencia. Las mejores capacidades se consiguen empleando garras con jamming lográndose coeficientes de correlación de 0.937 en índices de madurez con mangos y 0.872 en firmeza de berenjenas.
[CAT] La manipulació primària d'aliments amb robots precisa del desenvolupament de nous sistemes de manipulació especialment quan els productes són sensibles al dany i presenten una àmplia variabilitat de formes i textures. En el sector agroalimentari les dificultats són encara més grans ja que la manipulació manual serveix a més per a inspeccionar els productes durant el procés. Aquesta tesi aporta solucions a aquests problemes facilitant la incorporació de la robòtica. En la tesi es recopilen i analitzen diverses solucions per a poder manipular aliments proposant solucions concretes que després són validades amb prototips. La investigació es centra en aquells sistemes que són capaços d'auto adaptar-se a la forma dels productes sense incrementar la complexitat del mecanisme. Després d'analitzar diverses tècniques es proposa l'ús de mecanismes infra-actuats, mecanismes flexibles i dits amb fluids granulars que, tancats dins d'una membrana, es comporten com quasi-líquids o quasi-sòlids gràcies a la transició jamming, permetent una prensió inicial suau i la possibilitat de transmetre esforços elevats durant els moviments del robot. En la recerca d'urpes més lleugeres, senzilles, flexibles i econòmiques s'aprofita l'oportunitat que brinda la tecnologia de fabricació additiva de material. Gràcies a aquest procés es fabriquen mecanismes flexibles realitzats en una única peça i que equivalen a mecanismes d'urpes realitzats amb diverses peces rígides unides per articulacions. Mitjançant el sinteritzat per làser, es fabriquen actuadors pneumàtics, amb diversos tipus de moviment, basats en la flexibilitat del material emprat en la seva fabricació. En conjunt es simplifiquen els sistemes arribant a realitzar urpes flexibles de diversos dits fabricades en una única peça. Per a avaluar la qualitat i frescor dels productes agroalimentaris durant la manipulació s'empren acceleròmetres localitzats en els dits de diverses urpes. Els acceleròmetres són econòmics i es comporten com a sensors tàctils intrínsecs, sense estar en contacte directe amb el producte evitant desgastos per aquest motiu, i permeten identificar les diferents fases d'prensió. Per aconseguir això es desenvolupa un procés específic del robot amb l'urpa, que palpa diverses vegades el producte. Es fabriquen diversos tipus d'urpa amb diferents tecnologies de mecanismes infra-actuats i sistemes jamming i es programa un algoritme original de processat de senyal que, amb diverses tècniques, és capaç d'extreure paràmetres dels acceleròmetres que serveixen per a avaluar la qualitat dels productes. Aquests paràmetres són correlacionats amb les dades d'assajos destructius que són habitualment emprats com a referència. Les millors capacitats s'aconsegueixen emprant urpes amb jamming assolint-se coeficients de correlació de 0,937 en índexs de maduresa amb mangos i 0,872 en fermesa d'albergínies.
Blanes Campos, C. (2016). Garras con sensores táctiles intrínsecos para manipular alimentos con robots [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68481
TESIS

Advances in computing have resulted in many engineering processes being automated or otherwise computer-aided. Engineering design is one such process. The area of computer-aided design (CAD) emerged to support the design process. Conventional CAD systems are "non-intelligent" systems used to assist the later stages of engineering design, such as analysis and drafting within the detailed design phase. The conceptual design phase is of a different nature. It is qualitative and requires experience and creativity and is therefore not supported by conventional CAD systems. Techniques from the field of Artificial Intelligence (AI) may however be applied to the conceptual design phase. Using Al methods, Intelligent Computer Aided Design (ICAD) and Design Automation (DA) represent a departure from the routine number processing of design analysis and drafting. ICAD and DA involve the adoption of symbolic representation and reasoning for creative and innovative design conceptualisation. The aim of this work was to develop computer-based techniques to aid the conceptual design process, using the Al approach of Knowledge-Based Systems (KBS). To provide a concrete focus for the research, the developed techniques were applied to the problem of robot gripper design although they could equally be used for other design tasks. Conceptual design was considered from three perspectives. First, it was viewed as a configuration problem. A KBS has been developed to automate the configuring of new design concepts from existing sub-solutions. Second, design was seen as an adaptation problem. Another KBS has been created to achieve automatic retrieval and adaptation of previous design solutions to address new design requirements. Finally, design was regarded as an optimisation problem. A further system was developed to automate the generation of optimum gripping systems that can manipulate different components during assembly tasks.

Intelligent gripping may be achieved through gripper design, automated part recognition, intelligent algorithm for control of the gripper, and on-line decision-making based on sensory data. A generic framework which integrates sensory data, part recognition, decision-making and gripper control to achieve intelligent gripping based on ABB industrial robot is constructed. The three-fingered gripper actuated by a linear servo actuator designed and developed in this project for precise speed and position control is capable of handling a large variety of objects. Generic algorithms for intelligent part recognition are developed. Edge vector representation is discussed. Object geometric features are extracted. Fuzzy logic is successfully utilized to enhance the intelligence of the system. The generic fuzzy logic algorithm, which may also find application in other fields, is presented. Model-based gripping planning algorithm which is capable of extracting object grasp features from its geometric features and reasoning out grasp model for objects with different geometry is proposed. Manipulator trajectory planning solves the problem of generating robot programs automatically. Object-oriented programming technique based on Visual C++ MFC is used to constitute the system software so as to ensure the compatibility, expandability and modular programming design. Hierarchical architecture for intelligent gripping is discussed, which partitions the robot’s functionalities into high-level (modeling, recognizing, planning and perception) layers, and low-level (sensing, interfacing and execute) layers. Individual system modules are integrated seamlessly to constitute the intelligent gripping system.

Etude d'un robot avec un prehenseur tridigital. Le manipulateur possede six degres de liberte et est dote d'un capteur tactile d'efforts a six composantes. Conception d'une commande gardee avec retour d'efforts. Etude d'un logiciel de strategie d'assemblage. Experimentation dans le cas de taches d'assemblage de haute precision

This diploma thesis presents theoretical possibilities of force/torque control algorithms for industrial robots equipped with force sensor so it deals with interaction between industrial robot and environment. The most important types of control schemes are presented. Practical part deals with design gripper for specific workpiece and for grinding using industrial robot with force feedback. For this operation is given force/torque control design, using industrial robot KUKA KR16, FTC sensor SCHUNK FTC 50-80V and PLC. Further deals with compensation of gravity and dynamics forces.

The aim of this thesis is to create the design of a robotic workstation (RWS) for storing bags on a pallets with a capacity of 600 bags per hour. As an introduction to the issues of solved task, the introductory part of the thesis deals with a general information about industrial robots, theories ofdesigning RWS and palletization. For the suggested workstation it is given to have one pickup place from the roller conveyor and two unloading places. Within the RWS it is used belt, roller and chain conveyors as a peripheral device for conveying bags and pallets. There are two variants of RWS created for the possibility of technically - economic assessment. Solution for the security and the ergonomy of the workplace are an integral part of the study. Selected components of RWS have their risk analysis carried out. There is also the draft of a robot gripper mentioned, including assembly drawing. In conclussion there is calculation of returning of funds invested in the construction of RWS. Drawings of robotized workplace disposition, schemes of pneumatic and electrical connections and block diagram of the control system of RWS are included as attachments.

The work described in this thesis focusses on designing and building two novel physical devices in a robotic arm structure. The arm is intended for human-robot interaction in the domestic assistive robotics area. The first device aims at helping to ensure the safety of the human user. It acts as a mechanical fuse and disconnects the robotic arm link from its motor in case of collision. The device behaves in a rigid manner in normal operational times and in a compliant manner in case of potentially harmful collisions: it relies on a variable compliance. The second device is the end-effector of the robotic arm. It is a novel grasping device that aims at accommodating varying object shapes. This is achieved by the structure of the grasping device that is a soft structure with a compliant and a rigid phase. Its completely soft structure is able to mould to the object's shape in the compliant phase, while the rigid phase allows holding the object in a stable way. In this study, variable compliance is defined as a physical structure's change from a compliant to a rigid behaviour and vice versa. Due to its versatility and effectiveness, variable compliance has become the founding block of the design of the two devices in the robot arm physical structure. The novelty of the employment of variable compliance in this thesis resides in its use in both rigid and soft devices in order to help ensure both safety and adaptable grasping in one integrated physical structure, the robot arm. The safety device has been designed, modelled, produced, tested and physically embedded in the robot arm system. Compared to previous work in this field, the feature described in this thesis' work has a major advantage: its torque threshold can be actively regulated depending on the operational situation. The threshold torque is best described by an exponential curve in the mathematical model while it is best fit by a second order equation in the experimental data. The mismatch is more considerable for high values of threshold torque. However, both curves reflect that threshold torque magnitude increases by increasing the setting of the device. Testing of both the passive decoupling and active threshold torque regulation show that both are successfully obtained. The second novel feature of the robot arm is the soft grasping device inspired by hydrostatic skeletons. Its ability to passively adapts to complex shapes objects, reduces the complexity of the grasping action control. This gripper is low-cost, soft, cable-driven and it features no stiff sections. Its versatility, variable compliance and stable grasp are shown in several experiments. A model of the forward kinematics of the system is derived from observation of its bending behaviour. Variable compliance has shown to be a very relevant principle for the design and implementation of a robotic arm aimed at safely interacting with human users and that can reduce grasp control complexity by passively adapting to the object's shape.

The use of robotic systems in consumer goods industry has increased over recent years. However, food industry has not taken to the robotics technology with the same desire as in other industries due to technical and commercial reasons. Difficulties in matching human speed and flexibility, variable nature of food products, high production volume rates, lack of appropriate end-effectors, high initial investment rate of the so-called systems and low margins in food products are still blocking the range of use of robotics in food industry. In this thesis study, as a contribution to the use of robotic systems in food industry, a secondary packaging robotic system is designed. The system is composed of two basic subsystems: a dual-axis controlled robotic arm and a special-purpose gripper. Mechanical and control systems design of basic subsystems are performed within the scope of the study. During the designing process, instead of using classical design methods, modern computer-aided design and engineering tools are utilized.

碩士
臺北城市科技大學
機電整合研究所
104
The purpose of the thesis is to design the application of the End Effector which the industrial robots use, among them we need to consider the material of the tool tolerance level of power, the surface could be deformed or not and the sleek level…etc., also we take the clips of gripper according to the tool design. In addition to these points, we design exclusive adapters in order to correspond the six axis flange from different brands, so that we could fix it. In the thesis we also discuss the reason about why not choose traditional barometric pressure gripper and the importance of vacuum chuck.

碩士
國立臺灣科技大學
機械工程系
100
In this research, an embedded intelligent control gripper is designed and integrated with an ALTERA Nios II embedded control robotic arm. The end-effector position control and force control are designed separately with a signal to communicate for function switching consequently. Firstly, the position control mode is used to move the end-effector of manipulator to arrive the specified Cartesian coordinate, then it is switched into the gripper force control mode. ALTERA Nios II embedded development kit is employed to develop the Mistubishi RV-M2 hardware control architecture. The motor optical encoder decoding, limit switch detecting, pulse width modulation (PWM) generating and 1 bit communication signal with gripper were designed in Nios II hard circuit with HDL(hardware-design-language). Point to point motion control, inverse dynamics of robot arm, continuous motion trajectory control, sequential control and fuzzy sliding mode control soft programs are designed in Nios II interface. Arduino Nano 3.0 development board is chosen as the intelligent gripper control kernel for monitoring the gripper contacted force and position gap based on gripper FSR force sensor and a DC motor encoder feedback signals. The fuzzy sliding mode control is employed to design force and position controllers, respectively. The object stiffness can be constructed based on gripper position and contact force measuring information and an intelligent judge strategy. Then, the object can be handled with appropriate force without damage for pick-and-place operation. In addition, the object slip phenomenon is detected based on the force response of FSR and the contacted force command is regulated on-line to avoid the object falling.

碩士
國立臺灣科技大學
機械工程系
102
In this thesis, an two degrees of freedom intelligent gripper with embedded micro-control chip is designed and integrated with an five degrees of freedom industrial robotic arm. The robotic arm monitors end-effector position, and intelligent gripper control the tactile force. I^2 C communication protocol is established for these two independent systems structure. The robotic control system manipulator the end-effector of robotic arm to arrive the spatial target location firstly, then sends asignal by I^2 C to intelligent gripper. The intelligent gripper receives command to control the tactile force. Appropriate clamping force should be specified to avoid destroy objects due to excessive clamping force. In addition, the clamped object may slip during robotic arm motion due to dynamic variation. The clamping force should be adjusted based on measuring shear force variation. This control strategy would enhance the robustness in the robotic future operations. Arduino Nano development board is chosen as the intelligent gripper control kernel. This control system contains homemade motor drive circuit, potentiometer, I^2 C multiplexer, FSR force sensor and capacitive shear sensor etc. The intelligent gripper's tactile force control is based on FSR and capacitive tactile sensor feedback. The fuzzy sliding mode control is employed to design clamping force, shear force and position controllers, respectively. Robotic arm control architecture adopt ALTERA FPGA as control kernel. The Nios II development board use digital hardware circuits to achieve signal acquisition and output control function. FPGA digital hardware contain decoder, filter, PWM, I^2 C, IR and SDRAM controller etc. Nios II software contain user interface, kinematics formula, FSMC algorithm etc.

碩士
國立臺北科技大學
機電整合研究所
102
In this paper, we present a design of a gripper for a robot arm. Our research brings out a new driven mechanism with shape memory alloy instead of servo motor as our actuator, and also the gripper is equipped with a force sensor inside. The fuzzy sliding-mode method is our control rule, and furthermore there is an anti-slipping control rule to avoid grabbing unknown object with insufficient force. The whole control strategies are integrated into a Microchip dsPIC MCU with DSP core inside which is good at dealing with complicated float-point calculation. Gripper can change grabbing force in real-time based on fuzzy sliding-mode control due to different weight objects. Finally, we grab five different weight objects and some fragile objects with our gripper to verify our control strategy in the experiment.

碩士
國立交通大學
機械工程系所
103
In recent years, robot system have been applied more widely for assisting human beings to do the formidable or boring work, such as cleaning, maintenance, rescue etc.. This study focuses on the improvement and evaluation of the optimum parameters of robot gripper jaw with force-changing spring mechanism for climbing on the pole column in less energy. The innovative idea of the proposed claw mechanism composes the toggle mechanism and force-changing spring mechanism. It is expected that each finger can be winding to hold the column in various diameter adaptively with one actuator and multi-link design. The design of toggle mechanism is another key point of the claw mechanism for increasing the mechanical advantage while grasping the object. Since that the stability of the grasping status depends on several parameters of the claw mechanism, such as spring constant, angle of under actuation, friction coefficient, contact points etc. Some case studies related to the aforementioned typical parameters are proposed to be simulated for evaluation. The critical limit of the grasping force and actuating angle are also investigated for preventing the falling happened. The study and improvement of the proposed claw design with innovative mechanism is verified and demonstrated as an effective claw mechanism for practical use.

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia
O começo da quarta revolução industrial introduziu uma tendência corrente para o uso de tecnologias de automação onde os humanos e os robôs partilham o mesmo espaço de trabalho, a inteligência artificial apoia nas tomadas de decisão e onde todos os sistemas e utilizadores estão conectados entre si. Este novo paradigma trouxe os robôs colaborativos, resultando numa diminuição dos níveis de esforço humano devido a uma parceria eficiente entre este e a máquina, combinando a performance cognitiva e a capacidade de coordenação do utilizador com a precisão e capacidade de realizar trabalhos repetitivos do robô.Um robô colaborativo tem de incluir um gripper de modo a poder pegar as diferentes partes requeridas pelo seu utilizador. Os grippers tradicionais são projetados de acordo com determinadas tarefas, pelo que têm configurações específicas, normalmente inalteráveis, trazendo muitas limitações para o conceito de Indústria 4.0, onde a capacidade de adaptação a diferentes cenários com precisão é desejada. Em resposta à procura da indústria, grippers capazes de trabalhar com robôs colaborativos já existem, contudo o preço e o tamanho associado a estes cria uma barreira à sua aceitação na indústria.A motivação para este estudo é tentar atender a esta necessidade e o objetivo é criar um gripper de baixo custo, feito em impressão 3D, compacto e capaz de pegar diferentes objetos com uma elevada capacidade de adaptação. Além disso, a interação humana será tida em conta, dando ao utilizador um total controlo, em segurança, do gripper.Este estudo começa por definir e classificar os grippers convencionais de acordo com a sua cinemática, modo de atuação e quanto ao seu mecanismo de deslizamento. No final desta classificação é apresentado um resumo e uma comparação de desempenho entre estes.De seguida, é apresentado o conceito proposto, o Col-Gripper, descrevendo detalhadamente os protótipos desenvolvidos desde o design, a análise cinemática, a programação destes, até à implementação e realização de testes em cada geração do Col-Gripper.Por fim, é apresentada uma revisão acerca dos protótipos desenvolvidos, onde são analisadas todas as conquistas alcançadas em cada protótipo e são propostos desenvolvimentos futuros a realizar.
The beginning of the fourth industrial revolution, introduced a current trend of automation technologies, where humans and robots share workplaces, artificial intelligence supports decision-making and all systems and users are connected. This new paradigm brought collaborative robots, giving rise to a decrease of human effort levels with an efficient co-working partnership between the human and the machine, combining the cognitive performance and coordination from humans and the precision and capacity to produce repetitive work from robots.A collaborative robot has to include a gripper in order to grab different parts desired by its user. Traditional grippers are projected according to dedicated tasks, with specific configurations, normally unchangeable, which brings many limitations to the Industry 4.0 concept, where a capacity to adapt to different scenarios with precision is vital. In response to the industry demand, there are grippers to work with collaborative robots, but the high price and the large size associated became a barrier to their acceptance in the industry.The motivation behind this study is to try to fulfil this need and the aim is to create a low-cost gripper made in 3D printing that is compact and capable of grabbing different objects with a great adaptability. In addition, the human interaction will still happen by offering the user total control of the gripper safely.This study starts by defining and classifying conventional grippers according to their kinematic classification, driving force and sliding mechanism. An overview and a performance comparison between these grippers is made at the end of the classification.Then the Col-Gripper is introduced, describing in detail the developed prototypes involving its design, kinematic analyses, programming, implementation and the tests made with each generation of this gripper.Finally, there is an overview about the developed prototypes, analysing all achievements in each generation, and possible future developments are presented.

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia
Cada vez mais os robôs assumem uma posição fundamental na nossa sociedade, principalmente no sector industrial, dos quais destacam os braços robóticos, que possibilitam a execução de uma enorme variedade de tarefas.A correta manipulação dos objetos requer uma pega de boa qualidade logo, a evolução da garra robótica deve acompanhar a evolução do braço robótico. A abordagem tradicional reside em duas opções completamente diferentes, sendo a primeira o uso de garras convencionais que demonstram ser muito sensíveis a variações de posição e/ou orientação. Quanto à segunda, configura uma solução bem mais complexa (mãos robóticas antropomórficas), que garante um funcionamento quase perfeito, mas que tem como desvantagens um preço muito elevado e uma maior dificuldade de controlo. A designação de soft robotics surge como intermédio das opções anteriores e poderá representar o futuro em quase todas as áreas da robótica, particularmente nas garras robóticas. Estes instrumentos de manipulação, normalmente baseados em estruturas biológicas, assumem boas qualidades físicas e uma enorme capacidade adaptativa.O objetivo deste projeto é produzir uma garra robótica pelo princípio da Hybrid Deposition Manufacturing (HDM). O núcleo rígido, produzido numa impressora 3D, assume a responsabilidade estrutural, enquanto um composto polimérico proporciona a conformidade e a aderência necessária à garra robótica. Estas características asseguram as condições perfeitas de manipulação. Apesar de utilizar apenas um motor, as juntas flexíveis dos dedos agem de forma independente, gerando um bom desempenho na pega de diferentes objetos (forma, tamanho e orientação). Isto é possível pois o número de graus de atuação é muito inferior ao número de graus de liberdade da mão, onde apenas são dados os comandos para abrir e fechar. Para aumentar a qualidade da garra robótica e assegurar uma manipulação mais efetiva, foi utilizada uma câmera e um sensor ultrassónico (colocados nas laterais da mão), os quais são controlados a partir de um Raspberry Pi 3.Atualmente, o controlo de movimentos robotizados é executado por longas linhas de código, mas quando o local onde o robô opera é composto por pessoas com baixos conhecimentos de programação, é essencial procurar maneiras mais intuitivas de o fazer.A garra robótica resultante deste projeto é controlada através de um dispositivo de eletromiografia (EMG), convertendo os movimentos musculares em sinais digitais. Cada gesto tem um significado específico, gerando uma resposta específica, o que facilita o controlo do robô, melhorando a interação homem-máquina. Desta forma, torna-se possível o controlo de robôs por pessoas sem conhecimentos de programação.
Nowadays, the robots assume a fundamental position in our society, and even a major one when talking about the industry sector. The most common robots are the robotic arms which can execute an enormous variety of tasks. A correct manipulation of objects requires fine grasping capabilities so the evolving of the gripper should be parallel to the evolving of the robotic arm. The traditional approach resides in two completely different options, being the first one the use of conventional parallel grippers which demonstrate to be very sensitive to position and/or orientation variations. The second one consists of a solution much more complex (anthropomorphic robotic hands), which guarantees an almost perfect operation, having as disadvantage a higher price and a greater difficulty of control.Soft robotics emerges in the middle of these two options and will probably represent the future in almost all areas of robotics, particularly in robotic grippers. These manipulation tools, usually based on biological structures, assume good physical qualities and an enormous adaptive capacity. This project consists of a production of a flexible robotic gripper produced by the hybrid deposition manufacturing (HDM) principle. The hard core, built on a 3D-printer assumes the structural responsibility while a polymeric compost gives to the hand the compliance and the grip required to assure perfect manipulation conditions. Despite the fact of using only one motor, the flexural joints act independently generating a good performance when grabbing different objects (shape, size and orientation). This happens due to the fact that we are operating an under-actuated hand where the only thing controlled is the opening/ closing mechanism.In order to increase the quality of the gripper and to assure a more effective manipulation, it will be used a camera and an ultrasonic sensor (disposed on the hand laterals), which are controlled by a Raspberry Pi 3.Currently, controlling robotic motion is resumed by long lists of code but when the robot environment is composed by people with no coding knowledge, it is essential to search for more intuitive ways of doing it. The robotic gripper built on this project is controlled using an electromyography (EMG) device, converting the muscular movements into digital signals. Each gesture has a specific meaning, generating a specific response, which improves human-machine interaction (HMI). In this way, it becomes possible the control of robots by people without programming knowledge.

碩士
國立臺北科技大學
機電整合研究所
99
The purpose of this study is to design a flexible robot gripper that can catch a variety of items irregular shapes, which are mostly seen in the skill competition game. If a stable flexible robot gripper is successfully developed, it can be further used in industry. First, the literature studied vacuum, magnetic-type robot grippers and found that flexible robot grippers haven’t been deeply studied by anyone. Then we do a theoretical analysis, and make use of the theory of cantilever mechanics and the analysis of the holding force of the gripper so that the relationship between the structure of the flexible robot gripper and the holding force can be obtained. Then we process a series of tests of holding power of the flexible robot gripper. Comparing the tests by using a suspended system, it is found that the best design of the structure is to install 24 fingers with a length of 165 millimeter and a diameter of 0.4 millimeter. This design is the best choice for the gripper to catch items with the least work. The research result shows that the flexible robot gripper can catch items ranging from a diameter of 20 to 100 millimeter when it open and that an item of 3 kilogram can be taken by the gripper when the voltage is 6V.

碩士
國立臺北科技大學
機電整合研究所
103
In this thesis we present an intelligent robotic manipulator system which includes a gripper, a robot arm, and a webcam. In the gripper module, the shape memory alloy is used as actuator, and dsPIC MCU as controller. Force sensor is adopted for feedback to a fuzzy sliding-mode controller, so that the gripper can successfully grasp an object. In addition, a webcam is attached to the gripper module (i.e., eyes-in hand) of the robot. The robot is moved on purpose in two different positions for capturing the images. Digital image processing and binocular vision system model are applied to identify the object and obtain its 3D coordinates. This gripper is installed as the end effector of a Staubli robot. First, the proposed methods are implemented to identify the object shape and color, and its 3D position. Experimental results show that the robot manipulator system can correctly identify the target among different objects and calculate its position with relative error less than 5%. Finally, we carry out experiments to verify this intelligent gripper, and the results show that the presented methods can identify the target among other objects and do the pick-and-place task successfully.

碩士
淡江大學
電機工程學系碩士班
102
In this thesis, a mechanism design and implementation method of a six-axis robot manipulator, a mechanism design and implementation method of a gripper, and a control method for the gripper are proposed. In the design and implementation of the six-axis robot manipulator, a harmonic driver is designed and implemented, and some methods of strengthening mechanism rigidity and configuration reducer are proposed to improve the shaking problem of the previous six-axis robot manipulator. In the design and implementation of the gripper, a transmission mechanism with a voice coil motor is designed so that it can raise the gripper’s stroke to be twice of the maximum stroke of the voice coil motor. In the design and implementation of the voice coil motor control, a fuzzy controller based on a genetic algorithm is proposed to find an approximate optimal solution set of parameters so that the fuzzy controller can let the voice coil motor have a good control performance. Moreover, in the accuracy of the gripper’s opening and closing, a measurement platform is designed to measure the accuracy of the gripper’s opening and closing. From some comparison results, we can see that the implemented voice-coil-motor-based gripper controlled by the proposed control method does have better control results.

碩士
龍華科技大學
機械工程系碩士班
107
A design and control method of pneumatic shaping compliant gripper for the Six-DOF robot arm is proposed in this thesis, and a new type of gripper is designed with the advantages of universality, flexibility and soft contact. For the on-demand applications such as food packaging, material handling, and mixed production, the designed pneumatic shaping compliant gripper for the 6-DOF robot arm imports EtherCAT motion control technology to carry out system testing and control. In the robot arm mechanism design, as to improve the defects of the traditional robotic arm cable winding, the mechanical arm is designed with a tube structure, and with DC graphite brush motor and harmonic reducer, to design the robot arm. In the robot arm control, the core of controller adopts an industrial computer with the EtherCAT to build the motion control system. Then, the positioning and motion control can be correctly executed in accordance with the inverse kinematics model. In the gripper mechanism design of this pneumatic shaping compliant gripper, a flexible material with a shaping compliant finger is designed so that it can change the shape of three-finger to grip the object based on its shape. It can achieve the purpose that the gripper can successfully grip objects with various shapes. For the gripper control strategy, because the flexible material can conform to the surface of the object, the control part is mounted on the drive base install the Flanged Cylinder, and then the cylinder drives the link set to drive the gripper to grasp the object within the control range to achieve the gripping purpose. Some experimental results are presented to illustrate the designed shaping compliant gripper for 6-DOF robot arm with the gripper can effectively grab various objects.

碩士
南臺科技大學
電機工程系
104
The purpose of this thesis aims at the stereo vision to obtain the position of the object and track it by two-camera vision, and then grasping it by the robot arm and gripper based on this position information. The different placements of two-camera will result in different three-dimension coordinates of the object from two-camera vision. By way of the coordinate estimation correction method, the accuracy of position calculation will be improved. The robot analyzes the dynamic vision acquired from stereo cameras and tracks the object in the three-dimension space utilizing continuously adaptive meanshift (CAMSHIFT) algorithm. After that, the inverse and forward kinematics are implemented to control the movement of the manipulator to appropriate position and object-grabbing by the robot hand. In this thesis, the individual software of camera, gripper and robot arm will be integrated to a one user interface software that provide for operator. The cameras are set up beside the work space, not mounted on the robot arm and gripper. The system implemented by above-mentioned method can find and grasp the object successfully.

Miniature compliant grippers are designed and developed to manipulate biological cells and characterize them. Apart from grippers, other compliant mechanisms are also demonstrated to be effective in manipulation and characterization. Although scalability and force-sensing capability are inherent to a compliant mechanism, it is important to design a compliant mechanism for a given application. Two techniques based on Spring-lever models and kinetoelastostatic maps are developed and used for designing compliant devices. The kinetoelastostatic maps-based technique is a novel approach in designing a mechanism of a given topology and shape. It is also demonstrated that these techniques can be used to tune the stiffness of a mechanism for a given application. In situations where any single mechanism is incapable of executing a specific task, two or more mechanisms are combined into a single continuum with enhanced functionality. This has led to designs of composite compliant mechanisms. Biological cells are manipulated using compliant grippers in order to study their mechanical responses. Biological cells whose size varies from 1 mm (a large zebrafish embryo) to 10 µm (human liver cells), and which require the grippers to resolve forces ranging from 1 mN (zebrafish embryo) to 10 nN (human cells), are manipulated. In addition to biological cells, in some special cases such as tissue-cutting and cement-testing, inanimate specimens are used to highlight specific features of compliant mechanisms. Two extreme cases of manipulation are carried out to demonstrate the efficacy of the design techniques. They are: (i) breaking a stiff cement specimen of stiffness 250 kN/m (ii) gentle grasping of a soft zebrafish embryo of stiffness 10 N/m. Apart from manipulation, wherever it is viable, the mechanisms are interfaced with a haptic device such that the user’s experience of manipulation is enriched with force feedback. An auxiliary study on the characterization of cells is carried out using a micro¬pipette based aspiration technique. Using this technique, cells existing in different conditions such as perfusion, therapeutic medicines, etc., are mechanically characterized. This study is to qualitatively compare aspiration-based techniques with compliant gripper-based manipulation techniques. A compliant gripper-based manipulation technique is beneficial in estimating the bulk stiffness of the cells and can be extended to estimate the distribution of Young’s modulus in the interior. This estimation is carried out by solving an inverse problem. A previously reported scheme to solve over specified boundary conditions of an elastic object—in this case a cell—is improved, and the improved scheme is validated with the help of macro-scale specimens.

碩士
龍華科技大學
電機工程系碩士班
107
The present study established a six-degrees-of-freedom (6-DOF) robotic arm equipped with binocular vision and an adaptive gripper. The arm can be employed to sort and stack products in the modern manufacturing industry. Regarding the machine configuration, in response to the Industry 4.0 demands for low quantity, great variety, and flexible machining, the humanoid robotic arm established in this study has a merchant binocular vision system, a self-developed adaptive gripper that can grip items of different shapes, and a 6-DOF humanoid robotic arm developed in the laboratory. With respect to system analysis, the DH method was employed to establish forward and inverse kinematic models of the arm joints and end points. The scientific computing software MATLAB was used to verify the forward and inverse kinematics and simulate the working space of the robotic arm. For system control, industrial PCs and ethernet for control automation technology are employed. The visual programming software LabVIEW was used to develop image recognition and motor controlling programs for achieving integrated control of the binocular vision and 6-DOF robotic arm. In addition to meeting the low-quantity and great-variety demands of flexible manufacture in Industry 4.0, the system established in this study resolves the problems of complex cable configurations and the lack of depth perception of conventional robotic arms due to their monocular vision. The experiment results revealed that the 6-DOF automatic sorting robotic arm is capable of identifying the coordinates of objects using its binocular vision system and can automatically complete sorting and stacking tasks according to the shape of each object by using the robotic arm and adaptive gripper.

Deadlocks are critical events in Flexible Manufacturing Cells (FMC) that result from circular waits among a set of resources. Circular waits happen when a set of resources with finite capacity are in a permanent hold due to wait state to admit new jobs. Past literature examines the deadlock-free scheduling in FMCs considering many types of resources and techniques. This thesis proposes a new resource-oriented deadlock-free approach using a robot equipped with dual-grippers serving as a material handler in a FMC. The proposed methodology uses Constraint Programming (CP). The system performance is analyzed using different buffer configurations. Many test problems are generated to validate the developed models. The finding demonstrates that the proposed dual-gripper robot (DGR) can outperform the single-gripper robot (SGR) in many settings for FMCs. Likewise, the experience with the CP for the modeling and solving approach proposed in this research consolidates its application to FMC deadlock-free scheduling problems.

Genetic algorithms are inspired by the process of natural selection that exists in nature. This process is what leads species to evolve and adapt to their surroundings, with the fittest species reproducing, leading to new generations that can take advantage of their surroundings better than before. This type of process can be used in evolutionary robotics to achieve controllers that are able to solve specific tasks to evolve morphologies for a specific purpose such as to walk, swim, grasp objects, among others. Robotic grippers are used in most factories nowadays, as well as in other workplaces such as hospitals and laboratories. They are used in tasks such as grabbing/moving objects, painting, surgeries, among many other uses. Grippers are therefore a case study with several possibilities that lend themselves to evolving morphologies through genetic algorithms. In this dissertation, we explore morphology generation through genetic algorithms. Using grippers as our case study, we were able to generate grippers capable of grabbing and lifting an object. To evolve these grippers, we created a simulated environment where grippers followed a script with instructions to grab the object and then move up. In total 120 different grippers were generated in these experiments. Out of those 120 generated grippers, 28% were able to grab and lift an object successfully. After the evaluation process was completed, we experimented with the grippers in five different scenarios to test their robustness. In these scenarios, the object’s starting conditions were different from those in the evaluation process.
Os algoritmos genéticos são inspirados pelo processo de seleção natural que existe na natureza. Este processo leva espécies a evoluir e adaptar-se ao meio ambiente envolvente, com as espécies mais aptas reproduzindo, levando a que novas gerações possam tirar um melhor proveito do ambiente que as rodeia. Este tipo de processo pode ser utilizado na robótica evolucionária para evoluir controladores capazes de resolver tarefas de forma a evoluir morfologias para uma finalidade específica, tais como andar, nadar, agarrar objetos, entre outros. Garras robóticas são utilizadas na maioria das fábricas, assim como noutros locais de trabalho tais como hospitais e laboratórios. Podem ser utilizadas em tarefas como agarrar/mover objetos, pintura, cirurgias, entre outros usos. São, portanto, um caso de estudo com várias possibilidades que se prestam à evolução de morfologias através de algoritmos genéticos. Nesta dissertação, exploramos a geração de morfologia através de algoritmos genéticos. Utilizando garras como o nosso caso de estudo, conseguimos gerar garras capazes de agarrar e levantar um objeto. Para evoluir essas garras, criamos um ambiente simulado onde cada garra seguiu um script com instruções para agarrar o objeto e, em seguida, mover para cima. No total, 120 garras diferentes foram geradas nestas experiências. Dessas garras geradas 120, 28% foram capazes de capturar e levantar um objeto com êxito. Após a conclusão do processo de avaliação, experimentamos as garras em cinco cenários diferentes para testar a sua robustez. Nesses cenários, as condições iniciais em que os objetos começam eram diferentes das do processo de avaliação.

D.Ing.
The grasping strategy for a three dimensional object by a robotic gripper requires a geometrical reasoning and analysis of the physical gripper design, control and operation. The work addresses the problem of data acquisition and processing required for an object recognition and its application in the selection of grasping strategy for a given gripper. The system described in the thesis integrates the analyses of image data, object geometry and grasping operation in a systematic way. It is hierarchically constructed in several levels of analyses and processes including object recognition, grasping feature representation and classification, matching strategy for objects and the gripper and grasping description and operation. Object shape features are taken for recognition based on the image data collected through an infrared sensor. With a face relation graph proposed, an object model is built for describing the object geometrical properties and extracting its grasping features. A coding system based on group technology concepts is proposed for object classification. It describes object features relative to grasping operation. Gripping models are established and incorporated with the coding system for analysis of object gripping features. By means of the gripping models and the coding system, objects to be grasped are classified and grouped into specific families according to their similarities in gripping. The information transformation between the object and the gripper is made through a matrix representation. An object matrix describes the selection of gripping faces and object geometry for gripping , while a gripper matrix describes the fingers selection and its configuration in correspondence with the object to be grasped. The matching of the matrices is established through a knowledge-based reasoning approach. The grasping operation is controlled by a computer in terms of the commands generated by the gripper matrix through a gripper code. The design of the generic gripper for this application is described.

Indiana University-Purdue University Indianapolis (IUPUI)
This thesis proposes an automated grid-based alignment system utilizing lasers and an array of light-detecting photodiodes. The intent is to create an inexpensive and scalable alignment system for pick-and-place robotic systems. The system utilizes the transformation matrix, geometry, and trigonometry to determine the movements to align the robot with a grid-based array of photodiodes. The alignment system consists of a sending unit utilizing lasers, a receiving module consisting of photodiodes, a data acquisition unit, a computer-based control system, and the robot being aligned. The control system computes the robot movements needed to position the lasers based on the laser positions detected by the photodiodes. A transformation matrix converts movements from the coordinate system of the grid formed by the photodiodes to the coordinate system of the robot. The photodiode grid can detect a single laser spot and move it to any part of the grid, or it can detect up to four laser spots and use their relative positions to determine rotational misalignment of the robot. Testing the alignment consists of detecting the position of a single laser at individual points in a distinct pattern on the grid array of photodiodes, and running the entire alignment process multiple times starting with different misalignment cases. The first test provides a measure of the position detection accuracy of the system, while the second test demonstrates the alignment accuracy and repeatability of the system. The system detects the position of a single laser or multiple lasers by using a method similar to a center-of-gravity calculation. The intensity of each photodiode is multiplied by the X-position of that photodiode. The summed result from each photodiode intensity and position product is divided by the summed value of all of the photodiode intensities to get the X-position of the laser. The same thing is done with the Y-values to get the Y-position of the laser. Results show that with this method the system can read a single laser position value with a resolution of 0.1mm, and with a maximum X-error of 2.9mm and Y-error of 2.0mm. It takes approximately 1.5 seconds to process the reading. The alignment procedure calculates the initial misalignment between the robot and the grid of photodiodes by moving the robot to two distinct points along the robot’s X-axis so that only one laser is over the grid. Using these two detected points, a movement trajectory is generated to move that laser to the X = 0, Y = 0 position on the grid. In the process, this moves the other three lasers over the grid, allowing the system to detect the positions of four lasers and uses the positions to determine the rotational and translational offset needed to align the lasers to the grid of photodiodes. This step is run in a feedback loop to update the adjustment until it is within a permissible error value. The desired result for the complete alignment is a robot manipulator positioning within ±0.5mm along the X and Y-axes. The system shows a maximum error of 0.2mm in the X-direction and 0.5mm in the Y-direction with a run-time of approximately 4 to 5 minutes per alignment. If the permissible error value of the final alignment is tripled the alignment time goes down to 1 to 1.5 minutes and the maximum error goes up to 1.4mm in both the X and Y-directions. The run time of the alignment decreases because the system runs fewer alignment iterations.