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

Robotická manipulace s vysokotlakým zásobníkem paliva Common Rail při procesu svařování laserem / Robotic manipulation with Laser Welded Common Rail during the laser welding process

Bužga, Petr January 2015 (has links)
This master’s thesis deals with a description of Laser Welded Common Rail, which is produced by the company Bosch Diesel, s. r. o. in Jihlava. The theoretical part is focused primarily on a proposal for an industrial robot which would be manipulated with Common Rail during the laser welding process. The practical section is concerned with changes in the current paths of the robot to reduce production times, and to avoid using the same parts of the robot for the whole duration it is being manipulated with the Common Rail. At the end of this master's thesis is a techno-economic evaluation of previous alternatives, and it determines the appropriate option for robotic manipulation with the Common Rail during the laser welding process.
12

Návrh robotizovaného pracoviště pro automatické utahování šroubů spoje opěradlo – sedák a spony pásu / Desing of the robotic workstation for automatic tightening screws connections seatback – seat and belt buckle

Kafuněk, Jan January 2015 (has links)
This diploma thesis deals with the problem of designing an automatic robotic workstation for automatic tightening screws connections seatback – seat and belt buckle. The research part of this thesis deals with current trends in the automotive industry, especially with the problem of assembling seats part, with focus on screwing. The design part of this thesis maps the process of designing two variants of an automatic robotic workstation. Special attention was given to the process of choosing the right industrial robot for the task, as well as to the construction of the end-effector and of the resulting 3D data. The right version of the workstation for the consecutive implementation was then chosen based on multi-criteria evaluation. The finishing touch of this thesis is a risk analysis for the implemented workstation.
13

Real-Time Gesture-Based Posture Control of a Manipulator

Plouffe, Guillaume 20 January 2020 (has links)
Reaching a target quickly and accurately with a robotic arm containing multiple joints while avoiding moving and fixed obstacles can be a daunting (and sometimes impossible) task for any user behind the remote control. Current existing solutions are often hard to use and to scale for all user body types and robotic arm configurations. In this work, we propose a vision-based gesture recognition approach to naturally control the overall posture of a robotic arm using human hand gestures and an inverse kinematic exploration approach using the FABRIK algorithm. Three different methods are investigated to intuitively control a robotic arm's posture in real-time using depth data collected by a Kinect sensor. Each of the posture control methods are users scalable and compatible with most existing robotic arm configurations. In the first method, the user's right index fingertip position is mapped to compute the inverse kinematics on the robot. The inverse kinematics solutions are displayed in a graphical interface. Using this interface and the left hand, the user can intuitively browse and select a desired robotic arm posture. In the second method, the user's right index fingertip position and finger direction are respectively used to determine the end-effector position and an attraction point position. The latter enables the control of the robotic arm posture. In the third method, the user's right index finger is mapped to compute the inverse kinematics on the robot. Using static gesture with the same hand, the user's right index finger can be transformed into a virtual pen that can trace the form of the desired robotic arm posture. The trace can be visualized in real-time on a graphical interface. A search is then performed using an inverse kinematic exploration and the Dynamic Time Warping algorithm to select the closest matching possible posture. In the last two proposed methods, different search strategies to optimize the speed and the inverse kinematic exploration coverage are proposed. Using a combination of Greedy Best First search and an efficient selection of input postures based on the FABRIK's algorithm characteristics, these optimizations allow for smoother and more accurate posture control of the robotic arm. The performance of these real-time natural human control approaches is evaluated for precision and speed against static (i.e. fixed) and dynamic (i.e. moving) obstacles in a simulated experiment. An adaptation of the vision-based gesture recognition system to operate the AL5D robotic arm was also implemented to conduct further evaluation in a real-world environment. The results showed that the first and third methods were better suited for obstacle avoidance in static environments not requiring continuous posture changes. The second method gave excellent results in the dynamic environment experience and was able to complete a challenging pick and place task in a difficult real-world environment with static constraints.
14

Robotic cotton harvesting with a multi-finger end-effector: Research, design, development, testing, and evaluation

Gharakhani, Hussein 12 May 2023 (has links) (PDF)
Cotton is harvested with large and heavy machines that are very efficient but have some disadvantages. They can harvest the crop only once at the end of the growing season. Since cotton bolls do not mature uniformly, the early opened bolls expose their fiber to weather for extended periods, reducing lint quality. In addition, the machines can also compact the soil, reducing water and fertilizer usage efficiencies and crop yields in the following years. Robotic cotton harvesting offers a promising solution to these issues. Smaller robotic harvesters could go to the field multiple times during the season to pick cotton bolls as soon as they open. Such harvesters could be lightweight, minimizing the risk of soil compaction. This dissertation research includes designing an end-effector for robotic cotton harvesting, designing a robotic platform and integrating the custom-designed end-effector, and developing multiple manipulation control algorithms. The robotic platform has a 3-DOF (degrees of freedom) manipulator and a ZED 2i stereo camera. The robot was tested under lab and field conditions to evaluate its performance in object detection, localization, and picking. The tests proved that manipulating the arm while picking a boll increased the picking ratio – the weight of the picked seed cotton over the whole weight of the seed cotton that the robot attempted to pick – by up to 23%. However, it increased the cycle time. Therefore, the control algorithm was improved to a closed-loop system to touch just the unpicked areas of a boll. The best control algorithm, i.e., I-FMW (improved-feedback-based manipulation while picking), could achieve a 72.0% picking ratio with a cycle time of 8.8 s during lab tests. The field tests were conducted to find the contribution of three main systems (detection, localization, and picking) to the losses. The tests showed that detection, localization, and picking subsystems could achieve performance of 78.1%, 70.0%, and 83.1% respectively. Therefore, detection and localization systems must be improved. Utilizing better sensors, modifying detection and localization algorithms, adding the boll orientation information, and controlling illumination conditions as much as possible would improve the picking performance and make the robot a step closer to a commercial product.
15

DEVELOPMENT OF EXPERIMENTAL AND COMPUTATIONAL TOOLS FOR THE DESIGN OF VISUAL FORCE FEEDBACK FOCUSED COMPLIANT MECHANISM-BASED END-EFFECTORS

Duncan Joseph Isbister (15339403) 22 April 2023 (has links)
<p>Minimally Invasive Robotic Surgery (MIRS) has revolutionized the way modern surgery is conducted by allowing for smaller incisions, finer control, reduced pain, and faster recovery. The state-of-the-art end-effector technology used for MIRS are tools based off of the rigid-body instruments used in traditional ‘open’ surgery. The rigid nature of the end-effectors, specifically the grasping jaws, leads to a lack of force feedback when implemented in a robotic system. </p> <p>Without additional feedback from active sensing, the blanching that occurs from restricted blood flow around a grasping site is the only indication a surgeon can use to assess the force applied to a tissue. Ongoing efforts to develop active force sensing solutions are currently faced with two major obstacles: miniaturization and sterilization. The lack of force feedback causes a gap between intention and result during robotic surgery. </p> <p>This work proposes the introduction of Visual Force Feedback (VFF) through the integration of a compliant end-effector design. Visual Force Feedback is an intuition, developed through practice, that allows a surgeon to estimate the reaction force of a compliant mechanism by the deflection of the outer flexures. An understanding of the relationship between opening size, flexure deformation, and pinch force allows for rapid estimation of the force applied to a manipulated object. </p> <p>Force and dimensional data were gathered through finite element simulation and the finite element model was validated with physical experimentation on a custom test bench. Multiple functions relating the flexure deformation to the reactionary force, referred to as pinch force, for specific opening sizes were resolved. Notable observations made through the analysis of these results were: (1) a closely linear relationship between outer flexure deformation and pinch force in both experimental and computational results and (2) a higher rate of pinch force increase due to draw displacement as an effect of wider jaw opening. These findings are intended to help shrink the gap between intention and result in the field of MIRS.</p>
16

Design and Analysis of End-Effector Systems for Scribing on Silicon

Cannon, Bennion Rhead 06 August 2003 (has links) (PDF)
This thesis investigates end-effector systems used in a chemomechanical scribing process. Chemomechanical scribing is a method of patterning silicon to selectively deposit a monolayer of material on the surface of the silicon. This thesis details the development of a unique end-effector for chemomechanical scribing using a compliant mechanism solution. The end-effector is developed to scribe lines that have uniform geometry and produce less chipping on the surface of the silicon. The resulting scribing mechanism is passively controlled, has high lateral stiffness, and low axial stiffness. The mechanism is analyzed using the pseudo-rigid-body model and linear-elastic beam method to determine the axial stiffness, finite element methods to determine the lateral stiffness, and fatigue analysis to determine mechanism cycle life. This thesis also investigates the significance of mechanical factors on the chemomechanical scribing process using the compliant end-effector. The factors examined are scribing force, scribing speed, tip geometry, wafer orientation, and wetting liquid. The factors are analyzed using a two-step approach: first, an analysis of the influence of the mechanical factors on line characteristics and second, an analysis of the influence of line characteristics on line performance.
17

Návrh virtuálního modelu robotického pracoviště / Design of virtual model robotic workplace

Chromčík, Adam January 2018 (has links)
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.
18

Návrh robotické buňky pro manipulační operace / Design of a Robotic Cell for Manipulation Operations

Srdošová, Michaela January 2019 (has links)
This Master`s thesis deals automation of the workplace for manipulation operations. Robot’s role is take cooler from case, insert them into the dimensional and tightness device and then robot must place cooler on the output conveyor in robotic cell. The thesis describe deployment working cell, the selection and design process of each device and the robotic cell is designed with the safety standards. On the end in this thesis is a technical-economics evaluation. The simulation model in Process Simulate is a aim of this thesis, because we know working cycle time from this model.
19

Návrh robotického pracoviště na obrábění tvarově složité součásti válcovitého tvaru / Design of a robotic workplace for machining a cylindrical shaped part

Fajt, Petr January 2020 (has links)
This diploma thesis is about the design of a robotic workplace for machining complex components. The theoretical part briefly discusses the issue of industrial robots, end effectors and CNC machines. The practical part is about design of individual devices. First is designed end effector for the robot, then manipulator, output checking station and palletizing equipment. Then the entire workplace is assembled. Next there are performed control calculations and at the end a risk analysis is done for the designed workplace.
20

Návrh robotického pracoviště pro mazání komponent / Design of a Robotic Cell for Lubrication Application

Dlouhý, Rostislav January 2012 (has links)
This thesis deals with a robotic workstation for the specific application which is lubrication of components. There is designed a complete robotic cell including input and output devices. Its particular features are described. The task is based on the industry requirements and the projected workplace is replaced by manual labor. The original technology is replaced by an automatic solution. The whole workstation is designed with security in mind. They are used mechanical and electronic security features. The thesis contains economic evaluation of the workplace, including estimated payback period.

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