OPTIMIZATION OF REGULATION WORK PERIODICITY

OF MILITARI EQUIPMENT

Assoc. prof. Rumen Kodjeikov Ph D

Nicolay Petrov Ph D

Krasimir Kalev Ph D

Andrew Bogdanov

Artillery and Air Defence Military Academy – Shoumen

Air Investigation Base -Sofia

Abstract: The estimation of the regulatin work periodicity of the militery equipment is an extremelyimportant moment for its technical service. Many scientific publications concern this problem but most of them deal with a service process for an infinite technical exploitation period.In the present paper a solution of the problem for a limited interval of technical exploitation is suggested. A reliability model of the observed process is done as the intensity of the failure flux is chosen for a reliability criteria.

Key words: regulation works periodicity, military equipment, technical service.

Flux failure intensity for a final technical exploitation interval is estimated on the basis of BDS [1] according to:

, (1)

number of failures i of military equipment system for the observed interval;

the observed period of time (1 year for the Bulgarian army)

(2)

where p_o, p₁, p₂ …are coefficients determined by concrete points in the flux failure intensity function for t_i (i =0,1.2,3…) according to [2].

The complete military equipment statistics and (2) make possible the approximate reliability model of flux failure intensity through a linear function (after an initial moment t_o) in the regulation work interval:

(3)

where is the interval amount of flux failure intensity of moment t_o;

is the velocity of flux failure intensity increase for the observed interval .

The model (3) makes possible the optimum regulatin work periodicity estimation

which provides the military equipment system reliability for the observed period with least regulation works expenses.

For that purpose we consider military equipment worked out regularly over a certain period of time with periodicity. During the regulatin work the necessary expenses amont to C_pp.

For the time between the regulatin works when the total reconstruction of the military equipment is done the leading function of the failure flux can be expressed by the following formula according to [3]:

. (4)

We consider the expenses for the technical exploitation of the equipment for the period of the regulatin work in the folloing two cases:

• З_фс1 expenses only for current repairs.
• З_фс2 expenses for regulation works and current repairs.

exploitations of the military equipment :

, (5)

where m is the number of regulatin work for the observed period of time.

The number of regulatin work for the whole period of technical exploitation is defined according to [6] from:

, (6)

where k_pp is the number of regulatin work periods for the time t.

In formula (5) is the final interval for military equipment work under the condition where is the technical resource till the end of the technical exploitation .

Equation (4) and (6) are used for (5) investigation if only the current time parameter will be in time limit . We get the following:

    (7)

After investigating equation (7) we get the following differential equation:

(8)

There is no solution to (8) so we do:

. (9)

Filling (8) with (9) we get the following equation:

. (10)

Its solution is the next:

. (11)

We equalize (9) and (11) and get the algebraic equation:

(12)

To define the integration constant C_и we use from which follows m=1, k_pp=1.We use these in equation (12) and we get :

(13)

Filling equation (12) with C_и from (13) we receive the final:

(14)

Equation (14) proves the dependence of k_pp and . Filling in it we get the algebraic equation which is the link between and m. It is the following:

(15)

Solving (15) for we get :

. (16)

To get the real quantities equation (16) is solved under the following terms:

. (17)

Filling (15) with (16) we get

, (18)

where

Conclusions:

1. From equation (16) and (18) we can estimate the regulation works periodicity of the military equipment systems.
2. These equations make possible the estimation of the period numbers with definite regulation works for a certain technical exploitation period.

REFERENCE:

[1] БДС 27.002-86 "Надежност в техниката.Основни термини и опреде-ления", Комитет по качество към МС, София, 1987г.

[2] Коцев А.И., Петров Н.И., Петков Т.И., Методика за стохастическо прогнозиране на техническото състояние и ресурса на авиационната техника", ИВТ-София,1993.

[3] Димитров К.Д.,Данчев Д.И., Надеждност на строителни машини и системи, изд. “Техника”, София, 1994.

[4] Клюев В.В., Надеждность и ефективность в технике, Справочник, Москва, 1987, том 6.

[5] Рыбалов А.Г., Гладилин В.И., Метод отыскания основных харастеристик процесса восстановления, возникающего при систематическом устранение отказов в сложных авиационных систем, ВВИА “Жуковского”, Москва, 1968.

[6] Хетагурова Я.А., Надеждность автоматизированых систем управления,  “Высшая школа”, Москва, 1979.

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