SU1495837A1 - Device for determining initial time for unscheduled maintenance of article - Google Patents

Abstract

The invention relates to control devices and can be used in scientific research and engineering, when it is required to find the optimal moments for the start of control and maintenance operations on products. The purpose of the invention is to improve the accuracy by taking into account the time spent on troubleshooting. The device contains time sensors 1.16, blocks 2.5, 10 nonlinearity, integrators 3, 4, blocks 8, 9 multiplications, adders 6.7, registers 11.13, comparison block 12, coincidence element 14 and recorder 15. The invention allows Before performing especially important operations (special works), carry out additional measures to monitor the condition and restore operability of complex technical systems. 1 il.

Description

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with

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The invention relates to control devices and can be used in scientific research and techniques where it is required to find the optimal moments of the beginning of the execution of the operation of control and maintenance of products. ;

The purpose of the invention is to improve the accuracy of determining the moment of the start of an unscheduled monitoring of the product before using this product for its intended purpose by taking into account the time for troubleshooting.

The practice of operating some complex technical systems, such as manned or non-manned objects, shows that for a number of systems on board, it is imperative that additional, unplanned, state-of-the-art operations be carried out (responsible operations (advanced operations)). The aim is to bring it; systems in the highest readiness for use.

Usually, during the operation of the product, the current (planned, emitted) monitoring of the state of all its systems is carried out. The choice of the moment of the beginning of the unscheduled monitoring of the state of the systems and bringing these systems into operation, then the able state, in the event of violations in their work, allows you to achieve the maximum likelihood of the tasks set before the product

Suppose, when setting deadlines for unscheduled monitoring, the execution of special work V begins at time point t. | prior monitoring is carried out in moments

time t f.,; in the process of execution

 represents the likelihood of the product performing the special work, provided that at the time of control of the ty-r the product will work properly and will not fail until 40 times t. It is obvious that the probability value Pi, (t) does not depend on the time interval D and for given time points of the previous scheduled control t, y., I and the start of the complete discharge V, the failures in controlled 45 and special work t is the value

0

five

0

30 5

five

The interval should be more significant, since in order to eliminate possible failures that occurred in the system before performing the special work V, time is required to detect and localize the fault location, as well as the time to make a decision and control, i.e. recovery of performance.

Based on the above,

assume that there is such

: time interval C at which the maximum likelihood of performing a special work with a product is fulfilled.

If we denote by f (t) the density of the distribution of the uptime of the system, then f (t): the density of the time from

the start of monitoring until the moment of failure detection, and after f (t) - the density of time distribution from the moment of detection of the failure until its elimination,; something for the received

: constraints probability P (-O) of the V-th special work depending

: from time interval 1

 by expression

tv t

determined by f

PV () P "(t) + I ff (t) dt b

ff (C-x) .f. (x) (1)

6 f

The first component of this expression

iv / P (t) 1 - J f (t) dt

t Vt,

 represents the likelihood of the product performing the special work, provided that at the time of control of the ty-r the product will work properly and will not fail until 40 times t. It is obvious that the probability value Pi, (t) does not depend on the time interval D and for given time points of the previous planned control t, y., I and the beginning of the wavelength

 the system does not arise; the duration of the special work is significantly less than the time interval from the previous control session to the beginning of the special work.

We denote by the time interval from the beginning of the unscheduled monitoring to the beginning of the implementation of the special work V. Interdal time t is desirable to be insignificant so that the probability of trouble-free operation of the product by the time t, y of the beginning of the special work V is the greatest. In addition, this in0

five

constant.

The second term is a probability: that by the time t –f the product failed, but within the time period x (O x i;) the failure will be detected, and within the time interval the product will perform the special work V if the failure is detected at the moment time t y x.

; Based on the foregoing, the task of determining the timing of an unscheduled product control is reduced to determining the time interval RI for which the maxim rym probability and mjj5c HUS is reached, the performance of special work. Considering the independence of P (t) from G, ) - Pi, (t) and

Py (t) is achieved with one and the same

groin - With

however, it is sufficient to determine the maximum of the second term of Eq. (1).

The drawing shows the block diagram of the device, allowing to determine such a value at which Py / (r) PH () takes the greatest value.

The device contains a time sensor 1, the first nonlinearity unit 2, the first 3 and second 4 integrators, the second nonlinearity unit 5, nepBbtfi 6 and the second 7 adders, the first 8 and the second. The second input of block 9 multiplies the function f (- x), the selected short-circuit block 5 is not valid) in accordance with the time values 2 | - X obtained by the adder 7. The product obtained in block 9 multiplication is fed to the second input of the integrator 3, the first input of which

0, the value of the upper integration limit from the output of time sensor 1 is supplied.

Thus, to the second input of the block 8 multiply from the output of the integrator

15 4 value arrives

jf l (r- x) -f (x) dx.

i In: v-T

The product J f (t) dt j (x) t V-, °

 P ,,- ". 1л.f (x) dx, equal to the value of P. .. (f.) Swarm 9 multiplication blocks, third block 10 50 cho

"It is p, t), from the output of block 8 multiplying nonlinearity, first register 11, block a, 0", "for a time sign 12 indicated by time sensor 1, second register 13, element t m tment 14 matches, recorder 15 and second time sensor 16

The device works as follows 25 times.

The time sensor 1 with the pitch DT specifies, in order of increasing, the sequence of possible values of the interval C corresponding to the time from jg of the start of the unscheduled monitoring before the start of the special work V, fj f., + 4i, i l, ..., k. At each successive f value from the nonlinearity block 2, the function f (t) is selected and poured into integrator 4. From the first input of the device, the value of the upper integration limit t y is fed to the second input of the adder 6, the first input of which receives the value;. From the output of the adder 6, the value of the upper integration limit t - O is fed to the second input of the integrator 4. From the second input of the device to the third input of the integrator 4, the value of the lower integration limit ty- comes. From the exit

I.

For integrator 4, the value of Γ f A (t) dt is fed to the first input of the block with a multiplicity of eg 8.

35

40

45

A terminal is sent to the input of the first register 1 and to the first input of the unit 1 of the comparison. In this case, the previously entered into the first register 11 value) -P (t) is transferred to the second register 13 and then fed to the second input of the comparison unit 12.

In the initial state, before the device starts operation, both registers

(t transferred to zero state. In

subsequently, when transferring information from the first register to the second, earlier; the information recorded in the second register is deleted; In block 12 of the comparison, after the sensor 1 issues the time of the next value C; two values are compared, Py (.-)) and PyCi,) - "(t), one of which corresponds to the current value, and the other to the preceding

({. If as a result of such a comparison it turns out that

PV; -t) - Pn (t)) - P "(t)

or PvCC, -.,) PV (;).

TO from the first output of the comparison unit 12, a control signal is outputted to the first input of the first sensor 1, which allows the output of the next value of t. Otherwise, i.e.

At the same time, at each value of 1. a second time sensor 1.6 is triggered, setting continuous values of the time interval x, varying within il}, -, according to which the function f (x) is selected from the nonlinearity block 5 and fed. at the first input of the second block 9 multiply. The second input of the multiplication unit 9 receives the function f (- x), which is selected by the short-circuit block 5 is not valid) in accordance with the time values 2 | - X, obtained by the adder 7. The product obtained in multiplication unit 9 is fed to the second input of integrator 3, the first input of which is supplied with the value of the upper integration limit from the output of time sensor 1.

Thus, to the second input of the block 8 multiplied by the integrator

4 value arrives

jf l (r- x) -f (x) dx.

i In: v-T

The product J f (t) dt j (x) t V-, °

.f (x) dx, equal to the value of P .. (f.) t m t5

g

g

five

0

five

five

A cell is sent to the input of the first register 1 and to the first input of the comparison unit 12. In this case, the previously entered into the first register 11 value) -P (t) is transferred to the second register 13 and then fed to the second input of the comparison unit 12.

In the initial state, before the device starts operation, both registers

(t transferred to zero state. In

subsequently, when transferring information from the first register to the second, earlier; the information recorded in the second register is deleted; In block 12 of the comparison, after the sensor 1 issues the time of the next value C; two values are compared, Py (.-)) and PyCi,) - "(t), one of which corresponds to the current value, and the other to the preceding

({. If as a result of such a comparison it turns out that

PV; -t) - Pn (t)) - P "(t)

or PvCC, -.,) PV (;).

TO from the first output of the comparison unit 12, a control signal is outputted to the first input of the first sensor 1, which allows the output of the next value of t. Otherwise, i.e.

if P v (,) PV) of the output of the comparator unit 12, a permit signal is output to the coincidence circuit 14 and the value r ;. 2 opt. Of the second output of the time sensor 1 is fed to the input of the recorder 15. The operation of the device ends there.

Thus, the proposed device allows to increase the accuracy of determining the start of an unscheduled inspection of the product before it is used for its intended purpose by taking into account the time for troubleshooting. This time is a random value and depends on the location of the malfunction, as well as on the applied methods of control, i | g role and quality of means of control. Average time interval,; to which the moment must be transferred; The start of the unscheduled monitoring can be determined from the ratio; j

Claims (1)

; gi formula invented A device for determining the time e-; 2Q 1SH start performing unscheduled maintenance of a product containing the first: time sensor, the first output of which is connected to the first inputs of the nepBorq adder, the first integrator and; the first nonlinearity unit, the output of which is connected to the first input of the second integrator , the output of which is connected to the first input of the first multiplication unit, the second input of which is co gg Rdinen with the output of the first integrator, |: the second input of the first adder is with the first input of the device, the output Editor A. Shandor Compiled by N.Vaganova Tehred L, Oliynyk Order. 4271/48 Circulation 441 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 The first adder is connected to the second input of the second integrator, the third | input of which is the second input of the device, the second adder, the second nonlinearity unit, the first register, the output of which through the second register is connected to the first input of the comparison unit, the first and second outputs of which respectively, to the first input of the time sensor and to the first input of the coincidence element, the Ko-i code of the SECOND is connected to the recorder's input, characterized in that, in order to improve the accuracy of the device, a second multiplication unit is inserted into it, the non-linearity retimony block | and the second time sensor, the input of which jro and the first input of the second adder are combined and connected to the first V / - course of the first time sensor, the output; the second time sensor 1SH is connected to the second input of the second adder and through the third nonlinearity block the first | input of the multiplication unit, the output of the second adder is connected to the input of the second i nonlinearity unit, the input of which is connected to the second input of the second multiplication unit, the output of which is connected to the second input of the first integrator, the output of the first multiplication unit Keys to the input of the first register and the second inputs of the comparing unit. Corrector I.Gorn Subscription