Global ETD Search

1	Flight Telerobotic Servicer Keen, John 11 September 2015 (has links) In 2010, a donation was given to the University of Victoria Robotics and Mechanisms lab by Roper Industries. It was a Flight Telerobotic Servicer (FTS) Right Finger training tool. This is an electro-hydraulic robotic arm, approximately eight feet long, weighing in excess of four hundred pounds. This arm was designed and built in the late nineteen eighties as part of a program in support of the Space Station Freedom project. The intention of the arm was to assist in the training of astronauts in the use of an end effector which would be mounted at the distal end of the Canadarm©. The end effector would have right and left fingers, as well as a thumb (used for stabilization, not grasping). Unfortunately, the robot did not come with any of the control hardware, software, manuals, or functional descriptions, and the original equipment manufacturers (OEMs) were not able to share any information regarding the nature of the controls. The focus of the present work is to re-animate this arm without additional feedback, operating the arm only by hand-eye control, using currently available electronics and hardware. Also, investigate the absolute position sensors. These are described as near-infinite resolution analog absolute position sensors. Investigation was also conducted on an alternate solution (Vernier Optical Encoder), which was finally were abandoned. Strain-gauge type torque feedback sensors were found to be functional, and can be used without further work on future experimentation. The outcome of the research and assembly is a fully functional electro-hydraulic robotic arm, which is digitally controlled using an XBOX© game controller, using only visual feedback for position. The position sensor work was not as fruitful, with no working position sensors available. The torque feedback sensors are functional, but not utilized in the final work. / Graduate Flight Telerobotic Servicer Robot Robotic Vernier Optical Encoder
2	GPS/Optical Encoder Based Navigation Methods for dsPIC Microcontroled Mobile Vehicle Dincay, Berkan January 2010 (has links) <p>Optical encoders are being widely suggested for precise mobile navigation. Combining such sensor information with Global Positioning System (GPS) is a practical solution for reducing the accumulated errors from encoders and moving the navigational base into global coordinates with high accuracy.</p><p>This thesis presents integration methods of GPS and optical encoders for a mobile vehicle that is controlled by microcontroller. The system analyzed includes a commercial GPS receiver, dsPIC microcontroller and mobile vehicle with optical encoders. Extended kalman filtering (EKF), real time curve matching, GPS filtering methods are compared and contrasted which are used for integrating sensors data. Moreover, computer interface, encoder interface and motor control module of dsPIC microprocessor have been used and explained.</p><p>Navigation quality on low speeds highly depends greatly upon the processing of GPS data. Integration of sensor data is simulated for both EKF and real time curve matching technique and different behaviors are observed. Both methods have significantly improved the accuracy of the navigation. However, EKF has more advantages on solving the localization problem where it is also dealing with the uncertainties of the systems.</p> Kalman filter PIC robotics GPS optical encoder Vehicle engineering Farkostteknik Elektronisk mät- och apparatteknik
3	GPS/Optical Encoder Based Navigation Methods for dsPIC Microcontroled Mobile Vehicle Dincay, Berkan January 2010 (has links) Optical encoders are being widely suggested for precise mobile navigation. Combining such sensor information with Global Positioning System (GPS) is a practical solution for reducing the accumulated errors from encoders and moving the navigational base into global coordinates with high accuracy. This thesis presents integration methods of GPS and optical encoders for a mobile vehicle that is controlled by microcontroller. The system analyzed includes a commercial GPS receiver, dsPIC microcontroller and mobile vehicle with optical encoders. Extended kalman filtering (EKF), real time curve matching, GPS filtering methods are compared and contrasted which are used for integrating sensors data. Moreover, computer interface, encoder interface and motor control module of dsPIC microprocessor have been used and explained. Navigation quality on low speeds highly depends greatly upon the processing of GPS data. Integration of sensor data is simulated for both EKF and real time curve matching technique and different behaviors are observed. Both methods have significantly improved the accuracy of the navigation. However, EKF has more advantages on solving the localization problem where it is also dealing with the uncertainties of the systems. Kalman filter PIC robotics GPS optical encoder Vehicle engineering Farkostteknik Elektronisk mät- och apparatteknik
4	An Analysis of Critically Enabling Technologies for Force and Power Limiting of Industrial Robotics Smith, Gregory 28 August 2017 (has links) No description available. Robotics Torque Sensor Harmonic Drive Capacitive Sensor Optical Encoder Power and Force Limited
5	Mikroprocesorový modul řízení SS motoru se zpětnou vazbou / DC motor controler with feedback Dundáček, Martin January 2008 (has links) This thesis deals with DC motor control. Main goal was design and realization of DC motor controler module with feedback. The first part dwells on methods for DC motor control and HW design of control module. The second part describes development of software for the module, testing and sums up results.
6	Vývoj lineárního posuvu pro UHV STM/AFM / Development of a linear stage actuator for UHV STM/AFM Pavelec, Jiří January 2011 (has links) The aim of this diploma thesis is to develop a linear positioning stage for Ultra High Vacuum (UHV) environment. Simple prototypes of the linear positioning stage were designed and incorporated as part of a multiaxis sample manipulator for a UHV Scanning Tunneling Microscopy / Atomic Force Microscopy (STM/AFM). Different types of position encoders and linear guideways are discussed. Implementation of the homodyne interferometer as an optimization tool for a slip-stick based linear stage is described. Scalar diffraction theory is used to model the diffraction grating optical position encoder behavior.
7	Settling-Time Improvements in Positioning Machines Subject to Nonlinear Friction Using Adaptive Impulse Control Hakala, Tim 31 January 2006 (has links) (PDF) A new method of adaptive impulse control is developed to precisely and quickly control the position of machine components subject to friction. Friction dominates the forces affecting fine positioning dynamics. Friction can depend on payload, velocity, step size, path, initial position, temperature, and other variables. Control problems such as steady-state error and limit cycles often arise when applying conventional control techniques to the position control problem. Studies in the last few decades have shown that impulsive control can produce repeatable displacements as small as ten nanometers without limit cycles or steady-state error in machines subject to dry sliding friction. These displacements are achieved through the application of short duration, high intensity pulses. The relationship between pulse duration and displacement is seldom a simple function. The most dependable practical methods for control are self-tuning; they learn from online experience by adapting an internal control parameter until precise position control is achieved. To date, the best known adaptive pulse control methods adapt a single control parameter. While effective, the single parameter methods suffer from sub-optimal settling times and poor parameter convergence. To improve performance while maintaining the capacity for ultimate precision, a new control method referred to as Adaptive Impulse Control (AIC) has been developed. To better fit the nonlinear relationship between pulses and displacements, AIC adaptively tunes a set of parameters. Each parameter affects a different range of displacements. Online updates depend on the residual control error following each pulse, an estimate of pulse sensitivity, and a learning gain. After an update is calculated, it is distributed among the parameters that were used to calculate the most recent pulse. As the stored relationship converges to the actual relationship of the machine, pulses become more accurate and fewer pulses are needed to reach each desired destination. When fewer pulses are needed, settling time improves and efficiency increases. AIC is experimentally compared to conventional PID control and other adaptive pulse control methods on a rotary system with a position measurement resolution of 16000 encoder counts per revolution of the load wheel. The friction in the test system is nonlinear and irregular with a position dependent break-away torque that varies by a factor of more than 1.8 to 1. AIC is shown to improve settling times by as much as a factor of two when compared to other adaptive pulse control methods while maintaining precise control tolerances. control position adaptive impulsive settling-time nonlinear friction pulses displacements precise tolerances log-spaced update distributed learning Coulomb Stribeck Tomizuka Yang AIC PID MRAC STR RTAI Linux FreeBSD kernel modules microcontroller convergence practical self-tuning methods techniques limit-cycles steady-state error zero stable stability bound envelope partitioned scheme lookup-table multi-point adaptation repeatable mean servo motor exponential square-law rise-time real-time log-log interpolation pro-forma curve-fit sensitivity compliance variable static dynamic response torque acceleration velocity optical encoder parameters evolution fixed-law enhanced split weighting initialization trajectory layered processes Mechanical Engineering

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