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Leader: associate professor Krasnokutskiy V.A. Abstract made by Gomozov O.V. Introduction For today in coal industry of our country, and also other countries, one of sharp problems is providing of safety of workers. One of principal reasons of failures is an explosion of methane on mines, as a result of exceeding of his concentration in a mine atmosphere. For prevention of this in mines the automated systems of safety are used, fixing and supervisoring the state of mine atmosphere. The systems applied for today are morally, physically and technologically out-of-date, falling short of the high standards of safety and refuse stability. For their replacement to modern there are needed large facilities, but financial position of mines does not allow it to do. New checking system of mine atmosphere will be explored and projected in my master’s work on the basis of digital filtration with the use of digital signal processors(DSP). Indexes of this system will be comparable with the modern systems, but it will be cheaper than them. And advantage before out-of-date will be in reliability, refuse stability, speed, low-energy, adapted, universality, expansibility, easy tuning and exploitation, small sizes of eventual device. The purpose of this work is the checking system of mine atmosphere of an improvement, replacement of devices to more improved and increase of safety in mines. Aims and tasks of work The purpose of this work is development of practically-applicable algorithm of mine atmosphere analysis and it's application on new-class microprocessor complex . This work includes:
Practical value These research and project can be used as basics for realization in safety of mining industry, in particular new joint projects of MAKNII and DONNTU in this direction, and also as the example of practical application of digital filtration. Review of theme A hardware-programmatic complex KAGI(fig.1), developed by Makeevskiy SRI, basic part of which is DRTI (device of reception and transformation of information ), is used in the mines of Donbass, the main constituent of which is MSCM (microprocessor subcomplex of control and management). 
Fig 1. KAGI MSCM is able to get and process information from AS (automat of signaling), being in a mine and taking off testimony from 3 sensors of concentration of methane as high-frequency signals, whereupon this information goes to PC for a further analysis. For filtration of these signals the band-with filters of analog hardware are used. They are adjusted on frequencies of 14KHz, 20 KHz and 26 KHz , each of which is responsible for the state of one of sensors. At an accident rate (exceeding of concentration of methane of mark in 2,5%) these signals begin to be modulated frequency of 3-5 Hz . Signals are passed on a single wire, therefore we see their imposition, in addition there is a signal, which present in 1 KHz for telephone line, and also strong noises and loosening informative signals. After filtration the discrete (quantized signals) are formed, which through the blocks of MSCM are processed, transformed and get in PC, which is managed by an operator and sees a situation in a mine, making proper decisions. The conditional chart of work of the system is presented on fig.2. 
Fig 2. The conditional chart of work KAGI Conditional denotations: D1-D3 are sensors of concentration of methane, AS- automat of signaling, MSCM - microprocessor subcomplex of control and management and device of reception and transformation of information, PC is console terminal. As a result of planning will get a next chart in which in place of MSCM+DRTI a chart will be on the basis of signal processor DSP+ADC (fig. 3). 
Fig 3. Conditional chart of work of the designed system Analog filters are enough difficult devices. They require tuning in the process of making and exploitation. And also the followings failings are inherent them:
These failing result grow value of production and maintenance of the analog systems, complication of technological process, worsening of indexes of the system. The use of the digital signal processing (DSP) allows working out these problems. There are many types of filters , among them basic are the FFT-filters, IIR-filters and FIR-filters. My work is devoted possibility of last two application and to the choice of the best variant for the decision of our task. On the first stage of planning it is necessary to model the design of the future system, choice of necessary filter and parameters. The system of MATLAB, by which an utility was developed for a calculation and design, was used for this purpose, presented on a fig. 4, where it is possible to see one of experiments with the variant of optimum parameters. 
Fig 4. An utility of calculation and design of the system is in MATLAB Conclusion As a result of design of the system, modeled in MATLAB, the parameters of algorithm of digital filtration were certain, non-standard situations are explored and preliminary parameters are expected systems, DSP processor, ADC and other necessary elements can be chosen on the basis of. The developed algorithms and utilities of analysis of the state of mine atmosphere can be used as prototypes for realization of this system. The getting results say that in this system can be applied cheap 16 bit processors, PLM and other analogues. Application of digital filtration of signals in this system is allowed:
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