Introduction

Formulation of the problem. Modern and promising models of special communications are among the most science-intensive and high-tech types of industrial products, which are subject to increased requirements for quality and efficiency. The actual technical condition of special communications during their maintenance and all types of repairs is determined by analyzing the results of quantitative evaluation of the values of parameters and characteristics, which use metrological equipment [1,2].

Analysis of recent research and publications. The technical level of modern means of special communication and metrological equipment allows to take into account a significant number of factors that significantly affect the determination of the technical condition of special communication means [3].

This became possible thanks to the works of such famous scientists as V. Kaminsky, L. Vitkin, V. Ignatkin, O. Vasilevsky-in the field of determining the controlled quality parameters of metrological equipment; S. Ksenz, B. Kredentser, L. Sakovich-in the field of technical diagnostics of means of special communication; V. Chinkov, P. Stolyarchuk, B. Stadnyk, E. Pokhodylo, E. Volodarsky-in the field of development of metrological equipment; A. Friedman, P. Novitsky, V. Yatsuk, M. Yakovlev-in the field of development of the theory of metrological reliability.

At the same time, it should be noted the imperfection of the existing methods of forming general requirements for metrological equipment (and, in particular, the parameters of special communications), as they do not take into account the impact of diagnostic quality on maintenance of special communications.

The purpose of the paper is to develop and study a method of forming general requirements for metrological equipment on the example of special communication, which takes into account the functional dependences of the quality indicators of the diagnostic process.

Essence of the Method of Formation of General Requirements to the Metrological Equipment

The method of forming general requirements for metrological equipment is based on the process of substantiation of the minimum required values of metrological characteristics (MCH) of measuring equipment (ME) (as the main component of metrological equipment) used during maintenance and repair of special communications, to reduce their value with restrictions on the time of establishing the technical condition or recovery.

Its essence is to scientifically substantiate the values of metrological characteristics of measuring equipment based on the use of functional dependences obtained in [4,5], linking the value of the probability of correct estimation of the measurement parameter of special communication equipment with the average recovery time during maintenance and mathematical expectation deviation in the definition of a faulty element or a typical element of replacement of special means of communication. This task is performed under the condition and taking into account the performance of tests according to the conditional algorithm of diagnosing any form and type, which are built according to the recommendations of modern achievements of technical diagnostics.

The use of the proposed method involves taking into account the following limitations: the implementation of the current repair of special communications by the aggregate method; choice of measuring equipment from the established list; if there is one error in the evaluation of the measurement result of the parameter, the faulty element must be in the unit (unit, thesis, unit) which is being replaced.

The implementation of the proposed method involves taking into account the following assumptions: during maintenance or current repairs, the presence of no more than one defect in the MSC is assumed; in the process of determining the technical condition of the MSC is not allowed the presence of more than one error in the evaluation of the measurement result of the parameter; the procedure for performing inspections is set by the CAD MSC of the optimal form by the criterion of minimum v T ; maintenance or current repair MSC is performed by the crew of hardware communication or hardware technical support; the qualification of specialists corresponds to the position according to the staff list; the communication hardware and the technical support station have serviceable technological equipment and a complete set of documentation.

The limitations and assumptions correspond to the actual operating conditions of the MSC in the field.

The mathematical apparatus of the method is based on the use of methods of measurement theory, probability theory, discrete search theory, graph theory and discrete mathematics to obtain functional dependences of ME deviation of the technical state of the MSC from its true value under given constraints and assumptions, and computer simulation variables on the results.

The main functional dependences and analytical expressions used in the method are given in Table 1 [6,7].

The initial data are as follows:

L is number of TRE; y t is average troubleshooting time;

 is number of specialists; vd Т is allowable recovery time.

If 1  

and the MSC has built-in diagnostic tools, then enter the following:

Table 1 Indicators of quality of diagnostic support

Type of redundancy

Characteristic CAD

P v Т  Temporary U = 1 Repeat r the first B checks   K r p p  2   P t r K t y       1 1 2 2 Kr P p L K p L r p             Functional U = 2 Distribution of MSC of B parts B log K p 2    P t B L log t y  2     2 2 log 1 0.5 log 1 1 LB L L B B pp            Constructive U = 3

Binary CAD of the minimum form

K p P t Kt y      2 2 log 1 0.5 log 1 1 Zl ZZ ll pp            Information and structural U = 4 Modified inhomogeneous 2 2 1 1 K K p p P t t K t K y   2 2 1 1             12 12 1 12 1 12 1 1 1 1 1 22 1 1 0, 5 1! 1 1! KK K i KK KK iK p p p Mi p p p Mi                             If 1  

and the built-in diagnostic tools are absent, we enter the following: t is average time of performance of check; K is the average number of inspections; Z is the number of elements of the MSC; l is the number of elements in the TRE; U is type of redundancy of MSC ( 1

 U temporary, 2  U functional, 3  U constructive); B is division of the MSC into B parts; r is repetition of the first inspections on CAD. If 1   , then

The Main Stages of the Method of Formation of the General Requirements to the Metrological Equipment

The algorithm for implementing the proposed method involves the following steps: obtaining and analyzing the original data; under the condition of performance of works by one expert ( 1  

) and presence in MSC of the built-in means of diagnosis use algorithms of Figs. 1 and 2; for 1   and the absence of built-in diagnostic tools in the MSC using the algorithms of Figs. 3 and 4; under the condition of group search of defects depending on its type use algorithms of Figs. 5-7.

2 1 2 1 K K p p P  Start , , , , 1 1 2 1 t p K K 2 , , , , vd y Т t t M 1 1 2 2 y v K t K t t T P    Yes v vd T Т  No F3 Рис. 2.5 Yes 5 , 0   No 2 1 2 1 K K p p P  1 1 2 2 y v K t K t t T P    2 p , ,  2 1 2 1 1 1 1 K K p p p a    Start End   1 2 2 1 2 1 1    K K p p p в          1 1 ! 1 K i i M a c            2 1 1 1 ! 1 K K K i i M d   0.End Start U 3  U 1  U 2  U B log K p P 2     K r p p P   2   y v t K r t T P    K p P  y v Kt t T P     2 log y v t L B t T P  Start U 3  U 1  U 2  U B L log a 2  r K r L a     2 pa K L в     1 l Z a 2 log    p P p в 2 1    1    a B L в 1    a l Z в   2 1 1     a p p в End

Research Method of Forming General Requirements for Metrological Equipment

Consider the influence of the dimension of the object L on the quality of recovery p , P ,  , Their analysis shows that with given restrictions on the quality of restoration of the object with a small dimension, it is possible to use an independent group search for defects, which reduces the requirements for МE (

vd i L t Т N P      N i i K P p a Тв 1 ) (    1 0.5 1 K в p p       p, , v Т  End L log K 1    y t Kt a   Yes Yes No No vd a Т    1 K v d p a Т    1    L K в   в / p p K 1 1 1     1  p 0.001 p p   Yes Yes No No

No No

Yes Yes

 

, according to known methods determine MCH ME: accuracy class (KT), the division price and the length of the scale of analog ME [8][9][10] or the number of digits (r) digital ME. The cost of the ME will be minimal.

Example of Application of the Proposed Method

The order of use of the method is considered on the example of the selection of ME for maintenance of the path R-423 [11] for the following initial data from [7]:

51  L , 20 vd Тm  , 3 tm  , 5 y tm  , 2  n , 2  m , 2   .

The conditional algorithm of joint group search of defect is given in Fig. 12. The results of calculations are given in Table . 2. of the prototype). That is, the effect of the implementation of the method is equal to a 3% reduction in the requirements for the probability of correct assessment of the test result. This not only reduces the recovery time, but also significantly reduces the cost of ME used during the CR of the P-423 tract.

The novelty of this method is a comprehensive consideration of these factors and the development of a new algorithm for its implementation using the new analytical expressions obtained in the paper and the functional dependences of maintenance MSC indicators on controlled variables [12][13][14][15].

Scientific and Methodological Recommendations for the Practical Use of Research Results

The method proposed in the paper should be used when improving the system of technical operation of existing MSC, or when creating new models, in order to meet the requirements for the average recovery time with minimal ME costs.

Ensuring a fairly high level of efficiency of the State system of special communication and information protection of Ukraine is possible with a comprehensive solution to the problems of developing promising and operation of existing models of MSC with their appropriate technical support with minimizing the cost of maintenance, CR, and elimination of accidents and combat damage. Solving this problem requires not only the training of specialists in the operation and repair of the MSC, but also the creation of the necessary material and technical base, and a significant part of its cost is metrological equipment (and, in particular, ME). Therefore, the task of reasonable choice of the nomenclature of metrological equipment is relevant. This task is solved in order to ensure the necessary requirements for the reliability and maintainability of the MSC, provided the minimum cost of metrological equipment.

The accepted limitations and assumptions in the implementation of the proposed method fully comply with the conditions of technical operation, maintenance, CR and elimination of multiple defects of the MSC by the staff crews of hardware or hardware in the field.

Experimental verification of the received methodical recommendations on the basis of the offered method was carried out in 10 territorial nodes of the governmental communication and the State research institute of Special communication.

The method developed in the paper differs from the known availability of source data, taking into account not only the circuit and design features of the MSC, but also the use of all types of their redundancy to improve the efficiency of diagnostic software, which reduces the average recovery time and reduces the requirements for MCH ME, that is reduces their cost. The use of the method does not require additional training of repair specialists, was confirmed during the experimental verification of scientific results in the improvement of maintenance of the troposphere communication station R-423 in the 10th territorial node of government communication.

The obtained results are brought not only to the formalized methodology, but also to the corresponding software that allows their use in scientific institutions and industry of Ukraine.

Conclusions

The paper offers general provisions, essence, main stages, research results and an example of application of the method of formation of general requirements to the metrological equipment used during maintenance and current repair of special communication means.

Based on the results of experimental research of the obtained scientific results, recommendations for their practical use have been developed. It is positive that not only the activity of specialists during the implementation of the method is formalized, but software is obtained that allows the use of new scientific results in scientific institutions during the modernization of existing or development of promising samples of special communications for their effective maintenance using modern achievements discrete search theory in recovery.

Applying the developed method to other complex technical systems will give a correspondingly different effect. The use of the method does not require additional training of repair specialists, which was confirmed during the experimental verification of scientific results in the improvement of maintenance of the tropospheric communication station R-423 in the 10 th territorial node of government communication.