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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.
401

Process control and instrumentation methods for biomass fluidized bed gasifier operation

Campbell, William Allan 04 June 2010
A fluidized bed gasification (FBG) pilot plant was designed and constructed at the University of Saskatchewan Chemical Engineering Department Fluidization Laboratory. FBG is a thermo-chemical method for converting solid biomass to a gaseous fuel, termed syngas. Several instrumentation and control issues were particularly challenging with this pilot plant, including development of the fuel feeding system, pressure measurement of high temperature fluids, and metering of steam as a process reactant.<p> The fuel feeding system was tested using MBM (meat and bone meal) to determine the output rate stability, and predictability and measurability of the system as the components in the fuel feeding system were integrated. The fuel feeding system that was tested included a 150 mm primary metering screw conveyor, a 150 mm rotary airlock, and a 50 mm secondary injection screw conveyor. Each component of the system was fitted with a 3-phase electric motor and a variable speed drive to allow for a variable output rate. The weighing system that was integral to the metering conveyor was tested as well, but upon pressurizing the metering conveyor and hopper, the weighing system sustained an unreasonable amount of noise. Integrating a pneumatic injection nozzle with the injection conveyor was found to work effectively both under ambient temperatures and hot FBG conditions up to 725oC. Above 725oC, it was found that the test fuel would char and coat the nozzle, causing it to plug. Testing of the feeding system with the injection nozzle removed illustrated that the system could work well without it. It was determined that the injection conveyor speed to metering conveyor speed ratio that should be used for this system was 1:110 for absolute rotational speeds, or 1:1 of the full conveyor speeds. The complete system, including the injection nozzle, was analyzed and determined to produce a fuel output rate (FS) for % speeds from 5-25%, which roughly corresponded to the desired plant fuel feed rate of 1-5 g/s.<p> Techniques for remote pressure measurement of fluidized beds were examined as well, including the use of long tubes to cool hot gases and filters for blocking solid particles. The pressure measurement delay of these techniques was examined in comparison to a direct local measurement. This was conducted by comparing the pressure readings from two identical sensors; one mounted directly to a manifold, and the other mounted via a variable assembly (comprised of a variable length of 6.35 mm (1/4") PE tubing and a porous plate filter). Assemblies without a porous plate were found to have a minimal delay of up to 0.303 seconds for 30 m length of PE impulse tubing. More significant delays were found for systems using both a 10 media grade porous plate filter and impulse tubing; a 3 m tube length with filter has a delay of up to 0.221 s, and a 30 m impulse tube combined with the filter has a measurement delay of up to 1.915 s, a significant delay in cases where high-frequency analysis of pressure is used for bed agglomeration prediction, or systems where fast response is required to changing pressure conditions.<p> Additionally, a steam flow measurement system using an orifice plate and differential pressure sensor was installed and calibrated. By collecting time-based steam samples and process data, the physical system coefficients were determined for this system, allowing for steam flow measurement, accurate within 5% over a flow range of 0.5 to 2.0 g/s.
402

Framtagning av en utvecklingsprocess för automation - baserat på konceptet Lean Automation

Carnbo, Linda January 2012 (has links)
Due to the globalization today the competition in the market has in- creased and it requires flexibility and produce according to customer demand. In order to reduce the cost of wages industrial companies are now considering moving the manufacturing to low-cost countries. To keep up with the competition in the market without moving the manu- facturing abroad, Lean Automation was developed. The concept of Lean Automation is to reduce the perceived complexity with automa- tion and make automation available for new users and in new applica- tions. Haldex Brake Products are situated in Sweden and want to maintain the manufacturing of the automatic brake adjusters in the country. It is a product well-known and highly exposed to the competition in the mar- ket. Due to this situation Haldex are collaborating with Mälardalen University to develop a robotic cell based on the concept of Lean Au- tomation. It will be installed on their assembly line in 2012. The goal with this master thesis is to create a development process for automation, which can enable the company to be more competitive in the market and this by using their own knowledge to develop automat- ed solutions for higher efficiency in the production line. In addition to the development process for automation, programming of the Lean Au- tomation robotic cell is to be conducted. The conducted work in the master thesis was the programming of the robotic cell and the development process for automation. The pro- gramming was made Lean by reducing waste of time when working with the programmed code. This by a clear structure in the program- ming which makes it easy to handle. A development process for auto- mation was made and used for developing a robotic cell for the assem- bly line. The robotic cell was then tested at Haldex, an important stage before implementing the cell on the assembly line. Testing the robotic cell will give important information about how the equipment actually runs and failures can be observed and adjusted. Testing of the robotic cell will continue after the end of this master thesis.
403

Automatiserad produktionscell för lasersvetsning av fläkthus i titan

Lindblom, Anna, Wennberg, Frida January 2007 (has links)
För att vara framgångsrik i dagens tillverkningsindustri gäller det att vara konkurrenskraftig och komma med nya tillverkningssätt. Därför satsar Volvo Aero på lasersvetsning och automation. På Aero-Craft i USA grovbearbetas fläkthus i titan. Fläkthusets diameter är cirka tre meter och dess bakre del sätts idag samman från tre delar med hjälp av skruvförband och plasmasvets. Volvo Aero vill lasersvetsa dessa delar istället. En studie har därför påbörjats som skall visa hur en produktionscell för lasersvetsning skulle kunna se ut och fungera. Svetsarna är alla av typen stumsvetsar och det som skall svetsas är tre axiella skarvar, två rundskarvar och fastsvetsning av ett växellådsfäste. Innan svetsning häftsvetsas delarna först ihop och 3D-skanner används för inspektion. Efter att svetsen svalnat kontrolleras rundskarvarna av en digitalröntgen. Allt skall ske i produktionscellen. Resultatet presenterar en produktionscell uppdelad i två rum. Det första rummet är laserskyddat, och där utförs svetsning av axiella skarvar och växellådsfäste. Ett hål laserskärs ut där växellådsfästet skall sitta. Det andra rummet är både röntgen- och laserskyddat och där svetsas rundskarvar. En fogföljare med laserdiod och kamera används under svetsprocessen för att rikta laserstrålen efter skarven. I rum ett finns en processrobot och en hanteringsrobot och i rum två en processrobot. Fixturerna som presenteras i rapporten är endast konceptuella. Antalet fixturer är en till rum ett och två likadana till rum två. Fixtureringen i rum två utgörs av en expanderfixtur med rotgasbackar i aluminium. På Volvo Aero används vanligen expanderfixturer vid svetsning, men de har aldrig gjorts i den storlek som krävs för fläkthuset. Krav som ställs på manipulator är att den skall klara detaljens och fixturens vikt, samt att den skall klara uppsatta svetstoleranser.
404

Automatic Generation of Control Code for Flexible Automation / Automatgenerering av kod för flexibel automation

Svensson, Andreas January 2012 (has links)
In order to quickly adapt the production on a production line to the demand, there is a needfor flexibility. A tool designed for this purpose, p-sop, has been developed at UniversityWest. This thesis deals with implementation of p-sop in a demonstrator, and developmentof a framework for priority policies as well as a graphical user interface to p-sop. The prioritypolicies evaluated in the demonstrator did note give an increased efficiency, and thegraphical user interface is shown to be well suited for the demonstrator and p-sop in general.
405

Förstudie för automatisering av skateboardtillverkning

Cedervall, Andreas, Hök, Andreas January 2012 (has links)
This report is based on a thesis that was carried out during spring 2012. The report covers the development of a preliminary study to Performance Sk8. The purpose of the study is to facilitate and contribute inspiration to Performance Sk8 to run an automation project to bring home their production to Sweden from China. The reason is to gain a greater ability to control quality, produce smaller batches and reduce the cycle time to reduce costs. The goal is that the preliminary study shall meet the requirements and wishes Performance Sk8 and other partners defined. The pre study will contain different cost proposals for the automation of selected process and serve as a basis for procurement of the equipment. The pre study has resulted in some proposed solutions to the various steps required to automate Performance Sk8 ́s production. In addition to the proposed solutions are also concept proposal which has developed with suggestions for flows, prices and other information that can help Performance Sk8 in its ongoing automation project.
406

Examining the Process of Automation Development and Deployment

Barsalou, Edward January 2005 (has links)
In order to develop a better understanding of the process of development and deployment of automated systems, this thesis examines aspects of project execution and knowledge transfer in the context of a large automation project. <br /><br /> Background issues of project execution are examined, including the challenges of knowledge sharing in project development, as well as a brief discussion of measures of project success. The lifecycle of a large automation project is presented, including aspects of development and the development team, as well as design challenges inherent in the development process of a successful automation project which consisted of approximately 11,000 hours of combined effort by vendor and customer development teams. <br /><br /> Human factors aspects of large automation projects are explored, including an investigation of the workings of a large project team, by examining the cognitive aspects of the project team, as well as ecological aspects of the automation development process. <br /><br /> Using an interview methodology that can be termed the "echo method", project team members were interviewed in order to elicit helpful and unhelpful behaviours exhibited by other team members throughout the project. The results of these interviews are categorized and examined in the context of both knowledge management and social networks. Common themes in interview comments are identified, and related to both the areas of knowledge management and social networks. <br /><br /> Results indicated that team member experience and availability affect overall team performance. However, overlapping capabilities within a team were found to allow the team to adapt to changing circumstances, as well as to overcome weaknesses in team member availability. Better understanding of team interactions and capabilities supports improvements in project performance, ultimately delivering higher quality automation and streamlining the development process.
407

Process control and instrumentation methods for biomass fluidized bed gasifier operation

Campbell, William Allan 04 June 2010 (has links)
A fluidized bed gasification (FBG) pilot plant was designed and constructed at the University of Saskatchewan Chemical Engineering Department Fluidization Laboratory. FBG is a thermo-chemical method for converting solid biomass to a gaseous fuel, termed syngas. Several instrumentation and control issues were particularly challenging with this pilot plant, including development of the fuel feeding system, pressure measurement of high temperature fluids, and metering of steam as a process reactant.<p> The fuel feeding system was tested using MBM (meat and bone meal) to determine the output rate stability, and predictability and measurability of the system as the components in the fuel feeding system were integrated. The fuel feeding system that was tested included a 150 mm primary metering screw conveyor, a 150 mm rotary airlock, and a 50 mm secondary injection screw conveyor. Each component of the system was fitted with a 3-phase electric motor and a variable speed drive to allow for a variable output rate. The weighing system that was integral to the metering conveyor was tested as well, but upon pressurizing the metering conveyor and hopper, the weighing system sustained an unreasonable amount of noise. Integrating a pneumatic injection nozzle with the injection conveyor was found to work effectively both under ambient temperatures and hot FBG conditions up to 725oC. Above 725oC, it was found that the test fuel would char and coat the nozzle, causing it to plug. Testing of the feeding system with the injection nozzle removed illustrated that the system could work well without it. It was determined that the injection conveyor speed to metering conveyor speed ratio that should be used for this system was 1:110 for absolute rotational speeds, or 1:1 of the full conveyor speeds. The complete system, including the injection nozzle, was analyzed and determined to produce a fuel output rate (FS) for % speeds from 5-25%, which roughly corresponded to the desired plant fuel feed rate of 1-5 g/s.<p> Techniques for remote pressure measurement of fluidized beds were examined as well, including the use of long tubes to cool hot gases and filters for blocking solid particles. The pressure measurement delay of these techniques was examined in comparison to a direct local measurement. This was conducted by comparing the pressure readings from two identical sensors; one mounted directly to a manifold, and the other mounted via a variable assembly (comprised of a variable length of 6.35 mm (1/4") PE tubing and a porous plate filter). Assemblies without a porous plate were found to have a minimal delay of up to 0.303 seconds for 30 m length of PE impulse tubing. More significant delays were found for systems using both a 10 media grade porous plate filter and impulse tubing; a 3 m tube length with filter has a delay of up to 0.221 s, and a 30 m impulse tube combined with the filter has a measurement delay of up to 1.915 s, a significant delay in cases where high-frequency analysis of pressure is used for bed agglomeration prediction, or systems where fast response is required to changing pressure conditions.<p> Additionally, a steam flow measurement system using an orifice plate and differential pressure sensor was installed and calibrated. By collecting time-based steam samples and process data, the physical system coefficients were determined for this system, allowing for steam flow measurement, accurate within 5% over a flow range of 0.5 to 2.0 g/s.
408

Toward an understanding of optimal performance within a human-automation collaborative system: Effects of error and verification costs

Ezer, Neta 20 November 2006 (has links)
Automated products, especially automated decision aids, have the potential to improve the lives of older adults by supporting their daily needs. Although automation seems promising in this arena, there is evidence that humans, in general, tend to have difficulty optimizing their behavior with a decision aid, and older adults even more so. In a human-automation collaborative system, the ability to balance costs involved in relying on the automation and those involved in verifying the automation is essential for optimal performance and error minimization. Thus, this study was conducted to better understand the processes associated with balancing these costs and also to examine age differences in these processes. Cost of reliance on automation was evaluated using an object counting task. Participants were required to indicate the number of circles on a display, with support coming from a computer estimate decision aid. They were instructed to rely on the aid if they believed its answer or verify the aid by manually counting the circles on the screen if they did not believe the aid to be correct. Manipulations in this task were the cost of a wrong answer, either -5, -10, -25, or -50 points and the cost of verification, either high or low. It was expected that participants would develop a general pattern of appropriate reliance across the cost conditions, but would not change their reliance behavior enough to reach optimality. Older adults were expected to rely on the decision aid to a lesser extent than younger adults in all conditions, yet rate the automation as being more reliable. It was found that older and younger adults did not show large differences in reliance, although older adults tend to be more resistant to changing their reliance due to costs than younger adults. Both age groups significantly underutilized the computer estimate, yet overestimated its reliability. The results are important because it may be necessary to design automated devices and training programs differently for older adults than for younger adults, to direct them towards an optimal strategy of reliance.
409

Methodology for prototyping increased levels of automation for spacecraft rendezvous functions

Hart, Jeremy Jay 15 May 2009 (has links)
The Crew Exploration Vehicle (CEV) necessitates higher levels of automation than previous NASA vehicles due to program requirements for automation, including Automated Rendezvous and Docking (AR&D). Studies of spacecraft development often point to the locus of decision-making authority between humans and computers (i.e. automation) as a prime driver for cost, safety, and mission success. Therefore, a critical component in the CEV development is the determination of the correct level of automation. To identify the appropriate levels of automation and autonomy to design into a human space flight vehicle, NASA has created the Function-specific Level of Autonomy and Automation Tool (FLOAAT). This research develops a methodology for prototyping increased levels of automation for spacecraft rendezvous functions. This methodology was used to evaluate the accuracy of the FLOAAT-specified levels of automation, via prototyping. Two spacecraft rendezvous planning tasks were selected and then prototyped in Matlab using Fuzzy Logic (FL) techniques and existing Shuttle rendezvous trajectory algorithms. The prototyped functions are the determination of the maximum allowable Timeof- IGnition (TIG) slip for a rendezvous phasing burn and the evaluation of vehicle position relative to Transition initiation (Ti) position constraints. The methodology for prototyping rendezvous functions at higher levels of automation is judged to be a promising technique. The results of the prototype indicate that the FLOAAT recommended level of automation is reasonably accurate and that FL can be effectively used to model human decision-making used in spacecraft rendezvous. FL has many desirable attributes for modeling human decision-making, which makes it an excellent candidate for additional spaceflight automation applications. These conclusions are described in detail as well as recommendations for future improvements to the FLOAAT method and prototyped rendezvous functions.
410

Development of Systems to Improve Cotton Module Shape

Hardin, Robert Glen 2009 August 1900 (has links)
Properly constructed modules will prevent reduced lint value and increased ginning costs when significant rainfall occurs. Additionally, cotton producers often have difficulty finding adequate labor during harvest. These issues were addressed by developing a graphical operator feedback system, a biomass package measurement system, a powered tramper, and an autonomous module forming system. A system that provided feedback on the module shape by recording the position of the tramper and carriage was used to direct the operator to move cotton to appropriate locations. The system correctly predicted the height of 67% of data points. Use of the feedback system resulted in a 55% reduction in water collection area of the modules. The module builder operators indicated that the system was useful. The module builder feedback system is a simple, useful, and inexpensive tool that can have a rapid payback for producers. A powered tramper, with an auger to move cotton to the center of the module, was developed to replace the conventional tramper. The powered tramper operated automatically without affecting the operating speed or pressure of the tramper cylinder. During testing, the powered tramper was observed moving cotton to the center and crowned modules were produced. A biomass package measurement system was developed to record the height at multiple points on the top surface of modules. The system was found to produce repeatable measurements with an error of 5 cm. Data collected with this system did not indicate a difference in module shape when using the powered tramper; however, during these tests the powered tramper was turned off prematurely due to an improperly sized valve on the module builder. An automated module building system capable of both moving and tramping cotton was developed. This system utilized the feedback system sensors and photoelectric sensors to determine the location of cotton in the builder. A wireless display allowed the boll buggy operator to control the automatic system. The automatic system constructed modules with 64% less water collection area in an average time of 37.4 min. Cotton producers indicated that the system was easy to use and of significant value in reducing labor requirements.

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