Diseño y optimización de los subsistemas de un sistema de olfato electrónico para aplicaciones agroalimentarias e industriales
The general goal of the work of this doctoral thesis, as its name indicates, consists of developing, proving and to evaluate different strategies to improve the limitations that at the moment do that the Electronic Nose System are not used in real applications, fundamentally in applications related to the agro-alimentary industry, which requires an equipment urgently in the production plant. This objective can be subdivided in three great axes, whose results have allowed to resolve some important limitations of the Electronic Nose:
(1) Design, construction and evaluation of a prototype for the fungal detection in the industrial bakery products. In this first study it has been possible to determine the degree of effectiveness of different algorithms of variables selection that have allowed spectacularly to increase the reliability in the answer of a Electronic Nose System dedicated to the fungal detection in industrial baker's. The methodology developed for this objective is of easy implementation in any other application of the Electronic Nose system.
(2) Development of a system of detection of benzene in a CO2 flow. This second work has been oriented to study the real possibilities of increase in the sensitivity of commercial the semiconducting sensors in a real application, with interferentes and under an atmosphere not at all it causes to the operation of this type of devices as it is carbon dioxide. For it alternative designs based on a concentration process and thermal desorption have been evaluated, choosing the one that better result could offer and thus evaluating until point can be increased the sensitivity (and selectivity) of a Electronic Nose System by means of this philosophy. With the proposed design one has been able to increase the sensitivity of the equipment in a factor of 100 to 500 times, being in addition immune to interferentes in concentrations orders of magnitude over the volatile one to detect, the benzene.
(3) Design and construction of a flow modulation system with views to increase the selectivity of commercial the semiconducting sensors front to different gaseous species. This third objective includes so much the construction as the evaluation of the prototype that has allowed to verify that this strategy can be applied of generic form to any system of electronic sense of smell allowing the increase of selectivity of any tin semiconducting oxide sensor. The combination of the three previous strategies, that have been proven separately with great success, would have to allow to diminish the present limitations of a Electronic Nose.
Two chapters deals on the detection of fungi in products of industrial baker's shop with a electronic nose system. This application serves as excuse to verify as connecting a system of variables selection that can improve the operation of this type of instruments in agro-alimentary applications. Chapter three describes the works made with a prototype developed for real an industrial application. Different techniques from pre-concentration are tried, they determine so much the configuration as the optimal ways of operation, and the effectiveness of the prototype in a real application is evaluated. The third devised strategy to increase the effectiveness of the systems of electronic sense of smell is described entirely in chapter 4. In him to the mysteries of the design and connection of a system of modulation of flow to a SDOE are detailed and the results that have been obtained. In chapter 5 the conclusions obtained after the accomplishment of the studies described in chapters 2 are detailed, 3 and 4, aiming towards where they must continue the efforts in the lines of investigation treated in this doctoral thesis.
Advisor:Brezmes Llecha, Jesus Jorge
School:Universitat Rovira i Virgili
Source Type:Master's Thesis
Keywords:departament d enginyeria electrònica elèctrica i automàtica
Date of Publication:10/28/2005