Galugin Vyacheslav Vyacheslavovich
Abstract
on topic:" Intellectual systems of the aeration of excavation in mines"

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1. Urgency

           The intensification of mountain works is the basic direction of increase of productivity of collieries, and defines scientific and technical process at the coal industry. On maintenance of an intensive coal mining in various conditions the important place is directed decisions of some scientific problems miner's sciences among which occupy a problem of struggle against a gas barrier which limits productivity and negatively influences safety of work of miners.
           Problems of management of airing have caused in deep theoretical and to an experimental research of circuits of airing of sites, as of objects of management. Also an actual direction is system engineering of gathering and the analysis of the information on a condition of air in mine developments and contents of harmful gases and substances.
           By researches it is established, that function of concentration of methane is characterized by a gassed condition of different frequency. At restriction of value in some allowable size Сext all gassed conditions are deviations aside excess. They are connected with the advent of a dangerous situation. At absence of automatic control the situation uniform reaction to them is switching-off of the electric power on a site (that is a potential source of an inflammation methaneair mixes) and the termination of process of a coal mining. Operative liquidation of such gassed conditions is the primary goal of automatic control of ventilation as the task of maintenance of a continuity of technological process and liquidation of idle times of a technological line under the factor of gas evolution and a task of exception of danger of explosion of methane in developments in this case are solved.
The purpose of work is development of indistinct algorithm of management by ventilation in a site with a single lava.

2. Research of the developed algorithms

           As technological object we have a site with a single lava. The task of regulation consists in reduction of concentration of methane in mine a proceeding jet of the ventilating circuit to required value cт. Thus during regulation concentration of methane should not exceed maximum permissible value Cd. Deviations of concentration of methane aside reduction in comparison with cт also should be fulfilled from the point of view of economic feasibility of management as reduction of the charge of air by ventilation of developments causes essential reduction of expenses of the electric power.
           Regulation of concentration of methane is carried out by change of values of charges of air in system which are defined by values of aerodynamic resistance and depressions. Thus a task of management is process of change of parameters of the ventilating circuit with the purpose of reduction of value of concentration of methane required value, not exceeding a maximum permissible level of concentration.
For more evident description of processes of movement of air in the ventilating circuit of a site with a single lava, the following animated picture is below offered.


The ventilating circuit of a site with a single lava with the concentrated parameters


2.1 Algorithm of direct change of the charge of air

           The most simple decision of a task of regulation is direct change of the charge of air from Q0 up to Qт, where Q0 - the charge of air in a present situation of time, and Qт - the charge of air necessary for maintenance of concentration Cт.
           On the basis of the carried out experiments it is possible to draw the following a conclusion: change of concentration of methane at sharp increase in the charge of air is accompanied by long transient during which concentration of methane can exceed maximum permissible value.
It gives the basis to consider the above described algorithm inexpedient at use in real conditions.

2.2 Algorithm of linear safe management

           The algorithm of the linear safe management, allowing to avoid excess of allowable value of concentration of methane, and also it is essential to reduce time of transient.
The essence of a method consists in linear increase of the charge of air from Q0 up to Q1 (thus Q1> =Qт) and the subsequent linear reduction of the charge up to Qт. The increase is made during an interval of time dt1, and reduction - during an interval dt2. Linear reduction of the charge of air allows to reduce time of attenuation of splash in concentration of methane.
           Thus the algorithm of linear safe management allows to prevent excess of maximum permissible value of concentration of methane, and also in some cases allows to reduce time of transient.
           Lacks of algorithm are relative complexity of calculation of time intervals dt1 and dt2, providing the shortest safe transitive the process, and also small acceleration of transients in the ventilating circuit.

3. Algorithm of indistinct regulation

           Now the special urgency is got by the systems intended for support of decision-making processes, in particular advising and expert systems. We shall consider sphere of application of such systems.
It is conditionally possible to allocate two classes of objects with which it is necessary to face to experts in the field of automation of management. We shall name their "simple" and " difficult" objects of management.
           Objects, exact which mathematical models, for example as system of the algebraic equations or model of linear programming are "Simple", at the account of all necessary quantitative factors influencing behavior of object, are suitable for realization on the computer of the chosen class and quite adequate to object.
           As to "difficult" objects of management they have the following main distinctive features:
               1. Not all purposes of a choice of managing decisions and the conditions influencing this choice, can be expressed as quantitative ratios.
               2. Is absent or is the formalized description of object of management is unacceptable difficult.
               3. The significant part of the information necessary for the mathematical description of object, exists in the form of representations and wishes of experts - the experts who are possessing experience of work with the given object.
           Construction of exact mathematical models of difficult objects, suitable for realization and operation on modern computers, or is inconvenient, or in general it is impossible. Here the expert in the field of construction of models appears before necessity of a choice of one of alternatives. The first alternative - at construction of model of difficult object, as well as in a case of "simple" object to try to take into account all possible factors influencing behavior of object. Unfortunately, by virtue of specificity of objects of the given class, it is attempt « to grasp immense ».
           The second alternative - abstraction from some parameters of object with a view of reception of model more simple and convenient for realization. As a rule, this way also conducts by a unsuccessful outcome: the model turns out inadequate to object of management. Generally possible directions of search of the decision can be two. The first - to try to apply the nonconventional mathematical device to construction of the model which are taking into account all features of object and suitable for realization. The second direction will consist in attempt of construction not models of object, and model of management of object. Differently, the object, and the person - operator in managerial process by object is modelled not. It is natural that to model it is necessary the qualified operator well familiar with all features of management by the given object and successfully consulting with management by it "manually".
           Difficult objects of management - the most perspective sphere of application of systems with indistinct logic. The indistinct logic is used here for formalization of indistinct concepts from the point of view of their semantics and provides effective processing the qualitative information level with the precise, quantitative data. Moreover, use of indistinct logic at an estimation of developed situations and construction of the logic conclusions in models of management of difficult objects facilitates the decision of problems of maintenance of dialogue with the user in professional - guided language (that very important for advising systems), storages, accumulation and processings of the qualitative information. In our case as difficult object it is offered taking-out site with a single lava.
           Problems of management of airing have caused in deep theoretical and experimental research of circuits of airing of sites, as of objects of management. Also an actual direction is system engineering of gathering and the analysis of the information on a condition of air in mines and contents of harmful gases and substances.
           At absence of automatic control the situation uniform reaction to a unsafe situation is switching-off of the electric power on a site (that is a potential source of an inflammation methane-air mixture) and the discontinuance of process of a coal mining. Operative liquidation such загазованной is the primary goal of automatic control of ventilation as the problem of maintenance of a continuity of technological process and liquidation of idle times of a technological line under the factor gas evolution and a problem of exception of danger of explosion of methane in mines in this case are solved. The purpose of work is development of indistinct algorithm of management by ventilation in taking-out a site with a single lava.
           At a spelling of the given author's abstract magister’s work is not completed yet, final end: January, 2007. The full text of work and all materials on a theme can be received from the author after the specified date.

Literature

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4. Бойко В.А., Петречук А.А. Математическое описание выемочного участка шахты как объекта регулирования проветривания. - Изв. вузов. Горный журнал, 1972.

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