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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.
21

Enhancing stroke generation and expressivity in robotic drummers - A generative physics model approach

Edakkattil Gopinath, Deepak 08 June 2015 (has links)
The goal of this master's thesis research is to enhance the stroke generation capabilities and musical expressivity in robotic drummers. The approach adopted is to understand the physics of human fingers-drumstick-drumhead interaction and try to replicate the same behavior in a robotic drumming system with the minimum number of degrees of freedom. The model that is developed is agnostic to the exact specifications of the robotic drummer that will attempt to emulate human like drum strokes, and therefore can be used in any robotic drummer that uses actuators with complete control over the motor position angle. Initial approaches based on exploiting the instability of a PID control system to generate multiple bounces and the limitations of this approach are also discussed in depth. In order to assess the success of the model and the implementation in the robotic platform a subjective evaluation was conducted. The evaluation results showed that, the observed data was statistically equivalent to the subjects resorting to a blind guess in order to distinguish between a human playing a multiple bounce stroke and a robot playing a similar kind of stroke.
22

Modeling of robotic machining processes

Park, Chang Beom 11 October 2012 (has links)
Many high value-machining processes such as milling and drilling have been performed by expensive and dedicated (single purpose) machine tools including CNC machine tools. Industrial robots are a good alternative to these conventional dedicated machine tools due to the robots’ many advantages such as lower cost, larger workspace, higher flexibility of motion, and versatility. Despite these advantages, several barriers prevent them from being widely adopted for high value machining purposes. Two of these barriers are low and nonlinear stiffness of the industrial robot arm and the manufacturing end-users not knowing the capabilities and advantages of robots in machining applications. This research sets out to help a typical machining operator who is not an expert in robotics to learn the capability of a given robotic machining system. This study should help the operator plan robotic machining processes by presenting process models and visual maps for a variety of machining processes and workpiece materials. The study shows in particular how the cutting force and the compliance of a robotic machining system affect machining processes. To meet this objective, we present a framework for planning development for any given robotic machining application domain. First, we select primary performance parameters (including joint torque limit and end-effector positional error) and control parameters (including machining parameters, end-effector position, and workpiece position) for robotic machining. Then, we present the system models and visual performance maps for the functional parameters of robotic machining processes. The focus is on cutting forces for the ten selected machining processes and end-effector positional error of a robotic machining system due to the compliance of a robotic system (i.e., robot manipulator and cutting tool) and joint error (due to sensor error and gear backlash). Finally, we present five applications to show how to use visual maps for preliminary planning scnearios of robotic machining processes. The applications present a step-by-step process for selecting from cutting parameters to workpiece position parameters by utilizing performance requirements and visual maps developed in this research. / text
23

Parameter analysis for robotic assessment of impairments in reaching due to stroke

Abu-Zeid, Amr 05 October 2007 (has links)
Stroke is a condition that arises from partial or complete blockage of blood flow to parts of the brain. Upper limb impairments (sensorimotor deficits) usually occur as a result of stroke. Assessment and diagnosis of the resulting upper limb impairments is important for effective rehabilitation and proper recovery. In terms of assessment, current ordinal scale systems used are inherently subjective and incorporate coarse rating scores (Chedoke McMaster, Fugel Meyer test, etc.). These scores do not provide clinicians with information regarding the underlying impairments which is important for effective rehabilitation therapy. We investigated the use of a reaching task on a bi-lateral upper limb robotic device (KINARM), developed by one of our team members (Stephen Scott), to assess upper limb impairments due to stroke. Control and stroke subjects were instructed to reach with both arms on the robotic device to illuminating spatial targets as quickly and as accurately as possible. We first developed a tool that would aid in locating targets where reaching impairments are visible for stroke subjects. From the Kinematic data collected, we then selected reaction time and first peak velocity of the hand and investigated their potential for separating control and stroke subjects. Results of our analysis showed the potential of both parameters as good quantitative assessment measures. In particular results for reaction time presented symmetrical differences between both arms were of main interest in this thesis. Such differences presented the potential of sensitivity in showing subtle impairments. / Thesis (Master, Computing) -- Queen's University, 2007-09-25 11:54:00.694
24

Vision based seam following systems for automated welding

Smith, Jeremy Simon January 1990 (has links)
No description available.
25

Planning motion in contact to achieve parts mating

Koutsou, A. January 1986 (has links)
No description available.
26

Flexible magazine operation and cellular techniques in automation systems

Bedford, Stephen James January 1986 (has links)
There is a strong current trend in automation towards These often systems that can handle small to medium batch sizes are also often associated with In prototyping situations. Batch numbers High complexity the application described Is for British Airways Heathrow Airport where the number of variations pattern of their meal trays Is large. The batch size the assembly variations Is also extremely variable. Catering at in assembly of each of This thesis describes the justification and design of anautomatic system to assemble these trays whilst retaining the flexibility Inherent In the current manual assembly arrangement.The work examines system layouts. Considering each possibility particularly from the flexibility and potential reliabilityaspects. This leads to the consideration of Industrial robots because of their Inherent flexibility. Consequently the variousconfigurations of robots are examined to assess the suitability of each In a cell arrangement the system which was chosen forIts potential reliability. The work continues by developing the Ideas and techniques of parts feeding to realise the maximumbenefits from a robotic cell system." The thesis describes novel magazining arrangements for handling each of the Items which make. up the tray assembly. Two major developments are described. one for the handling of stackable Items and the other for handling small discrete parts from bulk. Both systems are flexible to accomodate variations In part dimensions and possess ability to be quickly re-configured - to handle completely different parts. The equipment designed and constructed for British Airwaysuses Ideas that could also find use In many similar applications where the components have the same characteristics.
27

Automation of garment assembly processes

Nicholson, Peter Raynor January 1987 (has links)
Robotic automation in apparel manufacturing is reviewed and investigated. Gripper design for separation and de-stacking of batch cut fabric components is identified as an important factor in implementing such automation and a study of existing gripper mechanisms is presented. New de-stacking gripper designs and processes are described together with experimental results. Single fabric component handling, alignment and registration techniques are investigated. Some of these techniques are integrated within a demonstrator robotic garment assembly cell automating the common edge binding process. Performance results are reported.
28

Simulation and control of a multi-axes pneumatically actuated animated figure

Uebing, Matthias January 1999 (has links)
No description available.
29

Further development, modelling and calibration of a laser tracking instrument for 3D dynamic measurement

Mayer, Joseph Raymond Rene January 1988 (has links)
The emergence of robots as essential components in the development of flexible manufacturing systems has created a demand for measurement techniques capable of measuring their performance. Typically it is required to measure the position of the robot end effector at speeds of up to 5 m/sec in a 1 metre sided cube and with a precision better than 0.1 mm. An instrument has been developed that uses a laser tracking technique and the principle of triangulation to determine the x,y and z co-ordinates of an optical target. It consists of two identical sub-systems, a retroreflective cat's eye target and a supervisory microcomputer. Each sub-system aims a low power laser beam at the target and detects the retroreflected beam for feedback to the mirror actuators controlling the beam direction. The instrument has been modelled, calibrated and evaluated. The effect on the target coordinate calculation of various system errors has been studied and a variety of measurement tools and methods are presented to calibrate the instrument both at component and sub-system level and also as a final system. The design of the cat's eye target is reviewed and a method of manufacture presented. Preliminary results and design details of a new optical sub-system with up-graded characteristics are also included. Tests show that the present instrument has a measurement accuracy of 0.03%, a repeatability of 0.01% (all for 1 standard deviation) for a measurement space of approximately one metre cube. The beam steering scanners have a bandwidth in excess of 74 Hz and the tracking velocity is approximately 3 m/s.
30

A robotic telescope for science and education

Baruch, John E.F. 01 April 2015 (has links)
No / John Baruch surveys the work of the Bradford Robotic Telescope – a project rooted in innovation and education, full of potential for an exciting future.

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