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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.
71

Evaluation of labview based control for a reconfigurable manufacturing subsystem

Masendeke, Darlington M. 03 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This thesis considers the evaluation of LabVIEW based control for reconfigurable manufacturing systems (RMSs), and in particular for an RMS subsystem. The evaluation used a rivet feeder station as a case study. The architecture of the rivet feeder station included a vibratory bowl feeder, a singulation device, a pick-n-place mechanism and an XYZ positioning table. The objective of the research was to determine whether LabVIEW is a suitable development environment for implementing holonic control. The motivation for considering LabVIEW in this thesis was that other control approaches, such as IEC 61499 function blocks, agent-based control and object-orientated control, that have been used in most RMS research, have not found favour with industry. The PROSA holonic reference architecture was adopted here, with the following holons: Coms Holon, Request Manager Holon, Order Holon, Product Holon Manager, Pick-n-Place Holon and XYZ Table Holon. The holons, constituting the controller, were designed based on LabVIEW’s producer/consumer and state machine architectures. The controller was aimed at making the rivet feeder station reconfigurable. Furthermore, the controller was interfaced with a cell controller through a TCP/IP connection and an XML format of messaging was adopted for communication. The main limitations and disadvantages of LabVIEW, for the implementation of holonic control systems, were found to be: the graphical programming which makes the block diagram cumbersome to follow, for complex applications; and that dynamic instantiation of objects or memory cannot be achieved in LabVIEW. However, LabVIEW holds the following advantages: shared variables and TCP/IP components simplify communication over a network; easy construction of the graphical user interface using controls and indicators on LabVIEW front panels; the XML standard format in LabVIEW provides flexibility to create your own unlimited tags; and immediate compilation of LabVIEW programs. Furthermore, LabVIEW easily can be integrated with hardware such as the compactRIO with a CANopen card. The reconfigurability assessment of the rivet feeder station included three experiments which involved changing the product type, adding new devices and performing station diagnostics. From these experiments, it was concluded that the key characteristics of reconfigurable manufacturing systems were achieved, thereby demonstrating the suitability of LabVIEW for implementing holonic control. / AFRIKAANSE OPSOMMING: Hierdie tesis beskou die evaluering van LabVIEW-gebaseerde beheer vir herkonfigureerbare vervaardigingstelsels (RMSs), en in besonder vir 'n RMS substelsel. Die evaluering het 'n klinknaelvoerstasie as gevallestudie gebruik. Die voerstasie se argitektuur het 'n vibrerende bakvoerder, 'n singuleringstoestel, 'n optel-en-plaas-robot en 'n XYZ-posisioneringstafel ingesluit. Die doelwit van die navorsing was om te bepaal of LabVIEW 'n geskikte ontwikkelingsomgewing vir die implementering van holoniese beheer bied. Die motivering vir die oorweging van LabVIEW in hierdie tesis was dat ander beheerbenaderings, soos IEC 61499 funksieblokke, agent-gebaseerde beheer and objek-georiënteerde beheer, wat in die meeste RMS-navorsing gebruik is, nie aanvaarding in die nywerheid gevind het nie. Die PROSA holoniese verwysingsargitektuur is hier gebruik, met die volgende holone: Coms Holon (kommunikasieholon), Request Manager Holon (versoekbestuurholon), Order Holon (bestellingholon), Product Holon Manager (produkholonbestuurder), Pick-n-Place Holon (optel-en-plaasholon) en XYZ Table Holon (XYZ-tafelholon). Die holone, wat die beheerder uitmaak, se ontwerp is gebou op LabVIEW se vervaardiger/verbruiker- (producer/consumer) en toetstandmasjien-argitekture. Die beheerder was daarop gemik om die klinknaelvoerstasie herkonfigureerbaar te maak. Verder, die beheerder het 'n koppelvlak met 'n selbeheerder gehad, waarin 'n TCP/IP-verbinding en 'n XML-formaat vir die kommunikasie-boodskappe gebruik is. Die belangrikste beperkings en nadele van LabVIEW, vir die implementering van holoniese beheerstelsels, het geblyk te wees: die grafiese programmering wat die blokdiagramme moeilik maak om te volg, vir komplekse toepassings; en dat objekte en geheue nie in LabVIEW dinamies geskep kan word nie. LabVIEW het, egter, die volgende voordele: gedeelde veranderlikes en TCP/IP-komponente vereenvoudig netwerkkommunikasie; gerieflike skepping van die grafiese gebruikerskoppelvlak met behulp van beheerders en meters (controls and indicators) op LabVIEW se voorpanele (front panels); die XML-standaard-formaat in LabVIEW voorsien buigsaamheid om jou eie onbeperkte etikette (tags) te skep; en onmiddellike vertaling van LabVIEW programme. Verder, LabVIEW kan maklik geïntegreer word met hardeware soos die "compactRIO" met 'n "CANopen" kaart. Die beoordeling van die herkonfigureerbaarheid van die klinknaelvoerstasie het drie eksperimente ingeluit waarin die verandering van die produktipe, die byvoeging van nuwe toestelle en die uitvoering van stasie-diagnoses betrokke was. Uit hierdie eksperimente kan afgelei word dat die sleutel-eienskappe van herkonfigureerbare vervaardigingstelsels behaal is, waardeur aangetoon is dat LabVIEW geskik is om holoniese beheer te implementeer.
72

Characterization of NI-USRP System

Fu, Xubo January 2014 (has links)
Nowadays the rapid developments of wireless communication technologies there are more and more ways to look into the RF measurements and designs in detail such as Universal Software Radio Peripheral(USRP) from LabVIEW, Advance Design System(ADS),etc.Moreover a lack of measurements what compared with different digital modulation schemes is becoming a problem. In this thesis by building the simulations of communication system in NI-USRP system and measuring the results then compare with the different PSK system in order to give a deeper insight of this new software of USRP from LabVIEW. and in the end analyze bit error rate varus signal to noise ratio from the PSK system. To get the characterizations of NI-USRP system the first step is to build multiple simulations such as FM receiver, PSK wireless communication systems. By performing the FM receiver is to analyze the quality of the receiving and baseband FM signal. And from the simulation of different PSK communications through the analysis of the performance of BPSK,QPSK,OQPSK and compared with bit error rate it could give an insight of characterization of NI-USRP system and in the end the conclusions give in which kind of prototype or simulation that suit the best of NI-USRP system.
73

Use of a Commercial Visual Programming Language to Simulate, Decommutate, Test and Display a Telemetry Stream

Wells, George, Baroth, Ed 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The advantages of using visual programming to create, modify, test and display a telemetry stream are presented. The failure to fully deploy the high-gain antenna of the Galileo spacecraft has resulted in a software redesign of the computer systems onboard the spacecraft to support the low-gain antenna mission. Visual programming software is being used to test new algorithms as part of the ground support for the spacecraft Test Bed. It is very important that any new software algorithms be thoroughly tested on the ground before any modifications are made to the spacecraft. The advantage of using a visual programming language (LabVIEW, National Instruments) is that it provides easy visibility into the decommutation process that is being modified by the Galileo programming support team. In addition, utilities were written using visual programming to allow real-time data display and error detection. A data acquisition board is used to clock in the actual synchronous telemetry signal from the Test Bed at rates below 10 kHz. The time to write and modify the code using visual programming is significantly less (by a factor of 4 to 10) than using text-based code. The gains in productivity are attributed to the communication among the customer, developer, and computer that are facilitated by the visual syntax of the language.
74

Implementation of a four probes measuring system to determine the resistivity of thin lms with temperature dependence

Salas Casapino, Carlos Alberto 28 June 2017 (has links)
Resistivity measurements in thin film samples depending on the temperature and on the film thickness is always a subject of interest, above all when it comes to new materials. This work presents the implementation of a measuring system for thin film resistivity based on four probes showing the dependency of the resistivity on the temperature as well as on the film thickness. In order to change the temperature of the samples, a heat source based on a Peltier element was implemented into the measuring system. A Graphical User Interface using a LabVIEW software controls all the devices of the measuring system and allows the user to calculate the thin film resistivity choosing between four measuring method: Van der Pauw, Modified Van der Pauw, Linear Van der Pauw and Linear Four Probes methods. Resistivity in aluminum and tungsten thin film samples with 100, 300, and 600 nm thickness were measured at temperatures between 303K and 373K with increments of 5 K. The results obtained are higher than bulk resistivity values and agrees with the present theory. Moreover, it is shown that the resistivity values obtained and its corresponding temperature coefficients increases as the film thickness decreases. / Tesis
75

System implementation of functional characterization of textiles electrodes for ECG measurements Software & Hardware components integration

Gismera García, Isaac January 2010 (has links)
The development in textile technology has led to electrodes and wearable measuringsystems. For the implementation of wearable systems is necessary to characterize properly theelectrodes and its influence in generating measurements. The validation of the performance oftextiles electrodes must be made with real ECG measurements.To obtain this ECG with textiles electrodes, a system must be implemented. This systemshould integrate an ECG amplifier, an USB DAQ system, the obtained data is received by aLabview application which stored this data in an ASCII text file. This text file is used tosubsequent study in a power analytical application, for example, Matlab.
76

Desenvolvimento em LabVIEW 8.20 de uma aplicação de controlo de um sistema de ensaios baixial

Sá, Diego Neves de January 2008 (has links)
Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2008
77

En kombination av Bluetooth och LabVIEW för ett universellt mätdatorsystem inom medicinsk teknik / A combination of Bluetooth and LabVIEW for a universal data acquisition system within medical science

Hjelm-Andersson, Alexander January 2004 (has links)
<p>Examensarbetet är utfört på Linköpings Universitet, Institutionen för Medicinsk Teknik och bygger på att undersöka möjligheterna för trådlös överföring av mätvärden via Bluetooth. Mätningarna gäller två olika hårdvaror som med metoden PPG mäter blodflöde, en ny förenklad hårdvara och en mer avancerad och tidigare utvecklad hårdvara. Arbetet är tvådelat, under första delen upprättades en kommunikation med Bluetooth och två metoder för överföring av data undersöktes. Under andra delen togs ett gränssnitt fram i utvecklingsmiljön LabVIEW för styrning av hårdvarorna samt för åskådliggörandet av mätdata. Metoderna som undersöktes för dataöverföring är att antingen kontinuerligt skicka samplat data direkt från en AD-omvandlare eller att fylla bluetoothmodulens minne för att därefter skicka samtliga värden samtidigt. För utvärdering av vilken metod som passar bäst för ändamålet diskuteras för- och nackdelar, samplingshastigheter undersöks och redovisas med hjälp av tabeller och grafer. Examensarbetet har resulterat i en grund för fortsatt utveckling av trådlös anpassning av mättekniska ändamålinom medicinsk teknik.</p>
78

Implementation of an FMCW Radar Platform With High-Speed Real-Time Interface

Svensson, Jonny January 2006 (has links)
<p>Acreo AB has developed a radar prototype used for illustrate how the SiGe technology could be used. The radar prototype needs further development with a fast interface and a more integrated design. The beginning of the report describes the radar technique theory and the composing equations. The theoretical background is used to explain each component of the system. The report continues by specifying the target of the next radar prototype. The chosen implementation is motivated and the mode of procedure is described in detail. Test benches were used to verify correct functionality and some limits were found. The report is concluded with test results and recommendations on further enhancements.</p> / <p>Acreo AB har utvecklat en radarprototyp för att illustrera hur SiGe teknologi kan användas. Prototypen behöver vidareutvecklas med ett snabbt digitalt interface och en kompaktare design. Rapporten inleds med att beskriva radarteknikens funktionalitet och de utgörande ekvationerna. Den teoretiska bakgrunden används för att förklara varje komponent som systemet utgörs av. Rapporten fortsätter med att specificera målet med nästa radarprototyp. Den valda implementationen motiveras och tillvägagångssättet beskrivs detaljerat. Testuppkopplingar verifierade korrekt funktionalitet och begränsningar insågs. Rapporten avslutas med en sammanfattning av uppnådda testresultat och rekommendationer på framtida förbättringar.</p>
79

Spectrophotometric measurement automatization for the analysis of enzymatic processes

Nilsson, Karolina January 2010 (has links)
<p>This thesis work consisted of the development of a virtual instrument that automates enzyme activity measurements and spectrum measurements with the spectrophotometer UVmini-1240. The purpose was to expand the functionality of the instrument, to eliminate the human error and to decrease the amount of time spent on measurements. A PC was connected to the UVmini-1240 via a RS-232C interface and the cell position and temperature was regulated with a CPS-240A controller. The new interface allows all the parameters to be set in the same place. It allows a visualization of the continuous monitoring of the sample absorbance and the option to save the data for post-processing. Also a module for measuring the spectrum of a sample in the wavelength range of 190 nm to 1100 nm is included. The graphical programming language LabView was used to develop the virtual instrument. This thesis work also contained measurement series of the catalase enzyme activity. These were carried out to determine the best storage temperature for the catalase solution and to determine the optimal surrounding temperature for the highest activity in the catalase solution. The conclusions were that the activity does not change considerably the first week of storage, not matter the temperature, and that the activity goes down when the surrounding temperature reaches above 30° C. These measurements were part of a bigger project to develop an ultrasonic method for measuring enzyme activity at the Institute of Acoustics at C.S.I.C in Madrid.</p>
80

En kombination av Bluetooth och LabVIEW för ett universellt mätdatorsystem inom medicinsk teknik / A combination of Bluetooth and LabVIEW for a universal data acquisition system within medical science

Hjelm-Andersson, Alexander January 2004 (has links)
Examensarbetet är utfört på Linköpings Universitet, Institutionen för Medicinsk Teknik och bygger på att undersöka möjligheterna för trådlös överföring av mätvärden via Bluetooth. Mätningarna gäller två olika hårdvaror som med metoden PPG mäter blodflöde, en ny förenklad hårdvara och en mer avancerad och tidigare utvecklad hårdvara. Arbetet är tvådelat, under första delen upprättades en kommunikation med Bluetooth och två metoder för överföring av data undersöktes. Under andra delen togs ett gränssnitt fram i utvecklingsmiljön LabVIEW för styrning av hårdvarorna samt för åskådliggörandet av mätdata. Metoderna som undersöktes för dataöverföring är att antingen kontinuerligt skicka samplat data direkt från en AD-omvandlare eller att fylla bluetoothmodulens minne för att därefter skicka samtliga värden samtidigt. För utvärdering av vilken metod som passar bäst för ändamålet diskuteras för- och nackdelar, samplingshastigheter undersöks och redovisas med hjälp av tabeller och grafer. Examensarbetet har resulterat i en grund för fortsatt utveckling av trådlös anpassning av mättekniska ändamålinom medicinsk teknik.

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