RU2275685C1 - Device for determining product reliability characteristics - Google Patents

Abstract

FIELD: computer science, possible use in scientific research and experimental engineering projects, where it is need to justify requirements to reliability of products.

SUBSTANCE: device has comparison block, splitter, adder, stepped voltage generator, keys, delay elements.

EFFECT: expanded functional capabilities of device due to determining value of intensiveness of product failures.

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Description

The proposal relates to computer technology and can be used in design developments where it is necessary to find the value of the failure rate, ensuring the product is ready for operation for the intended purpose not lower than the specified value.

Known works [1, 2] devoted to the substantiation of the requirements for the reliability of elements of complex systems. They propose approaches to establishing rational boundaries of the reliability of elements, showing the unjustified aspirations for maximum reliability of system elements due to economic and technical inappropriateness.

Known devices [3, 4], allowing to determine the values of the periods of maintenance, providing the required readiness of the product for use. Their disadvantage is low functionality. They are focused on existing products and do not allow to find rational values of the failure rate of developed products. It is also known a device [5], designed to determine the value of the failure rate, providing a maximum of the useful life of the product at a given period of its maintenance. The disadvantage of this device is the narrow scope, as it is focused on products whose status is monitored during scheduled sessions. In addition, these products have a limited resource "life". The expenditure factor of this resource is reflected in the value of the desired value of the failure rate. We also note that in the diagram and claims of the device [5] there are a number of errors that do not allow us to consider it as a prototype (one of the blocks 23 is erroneously included, several inter-unit communications are not reflected).

The closest in technical essence to the proposed invention is a device [6], containing a step voltage generator, two adders, two multiplication units, two integrators, two amplifiers, two dividers, a comparison unit and a key. It allows you to determine the value of the failure rate of the product, which for a given period of maintenance of the product provides maximum useful life of the product. The disadvantage of this device is the narrow scope, since it is focused on products with a limited supply of material resource spent during operation. The rate of expenditure of this resource is reflected in the value of the desired value. At the same time, there is a wide class of products for which such a resource is not decisive from the point of view of ensuring the quality of the product’s functioning, since its supply is sufficient for normal functioning (for example, stationary power grid energy). Otherwise, the resource will fail. Most important is the high degree of readiness of the products for their intended use, determined by their reliability characteristics, operating modes and external factors.

The aim of the proposed technical solution is to expand the scope of the device by determining the failure rate, providing the required readiness of the product for use.

There is a wide class of products for continuous use. A feature of the functioning of such products, according to [7], is their stay at any time in one of the following possible states:

- workable when the product is used or can be used for its intended purpose;

- Inoperative if the product has failed.

A comprehensive indicator of the quality of the product is the availability factor. For the specified class of products, it is expressed by the following ratio:

- среднее время безотказной работы,Where

- average uptime

- среднее время восстановления работоспособности изделия в случае возникновения отказа.

- the average recovery time of the product in case of failure.

With the exponential law of the distribution of the operating time per failure, the failure rate λ and the average uptime are related by the relation:

The recovery rate μ and the average recovery time of the product in case of failure is as follows:

Then relation (1) takes the following form:

Based on the foregoing, the problem of determining the required value of the failure rate will be formulated as follows: determine the value of the failure rate that ensures the operation of the product with a availability factor of at least a given, that is:

The proposed mathematical model can be implemented in hardware.

The drawing shows a diagram of the inventive device. It contains a comparison unit 1, a divider 2, an adder 3, a step voltage generator 4, a first switch 5, a first delay element 6, a second delay element 7 and a second switch 8.

The device operates as follows. From the first input of the device to the comparison unit 1, a signal corresponding to a given value of the availability factor K _g ^ass . From the second input of the device, the first inputs of the adder 3 and the divider 2 receive a signal corresponding to the value of the intensity of restoration of the product’s working capacity μ. The step voltage generator 4 acts as a failure rate sensor. It specifies, in increasing order, a sequence of possible values of the failure rate λ _i = λ _i-1 + Δλ; i = 1, 2, 3, ...; λ ₀ = 0. From the output of the step voltage generator 4, the signal λ _i goes to the second input of the adder 3 directly, and through the second delay element 7 to the information input of the second key 8. In the adder 3, a signal λ _i + μ is generated and transmitted to the second input of the divider 2. In the divider 2, the value of the availability coefficient is calculated in accordance with the relation (2), that is, K _gi = μ / λ _i + μ. The signal K _{plaster Gi} is transmitted directly to the second input of the comparator unit 1 and through a first delay element 6 - to an information input of the first switch 5. compared between the values of K _z and K _{plaster Gi} ^backside In comparison 1 block. If it appears that K _{plaster Gi> g} K ^ass, the control signal output from the first comparator unit 1 goes to a step input voltage generator 4. At this signal at the output of the generator 4 will be a new value of the failure rate λ _{i + 1} = λ _i + Δλ and the process of calculating the availability factor will be repeated. This will continue until the inequality K _gi ≥K _g ^{ass is} fulfilled. As soon as it turns out in comparison unit 1 that K _gi <K _{g is the} ^rear , the control signal will appear at its second output. At this time, at the information input of the first key 5, the signal K _g ^subt = K _gi-1 , delayed by the first delay element 6, acts, and the signal λ ^subt = λ _i-1 delayed by the second delay element 7, is delayed by the second input element 8. This is due to the fact that the time of the first 6 and second 7 delay elements is the same and corresponds to the duration of one cycle of calculating the value of the availability factor and comparing it with a given value. According to the control signal of the comparator unit 1 keys 5 and 8 are opened, whereby the first output device is the calculated value of the coefficient Kr ^calc readiness, and the second output - the failure rate calculated value λ ^calc. This completes the operation of the device.

The positive effect that the proposed technical solution provides is that the device allows you to determine the desired value of the failure rate of the product, providing the necessary readiness for use.

Information sources

1. L.N. Chuprov. Distribution of requirements for system reliability between its elements. On Sat The main issues of the theory and practice of reliability .: - M .: Sov. Radio 1975, pp. 98-106.

2. Yu.S. Kovalenko, V.Yu. Muratov. Method for the distribution of requirements for the reliability of elements of complex systems. In: Reliability, Quality Control, 1975, No. 9.

3. G.N. Vorobiev, V.D. Grishin, V.T. Domozhirov, A.N. Timofeev. AS of the USSR No. 1767510, G 07 c 5/08.

4. V.D. Grishin, A.N. Timofeev, M.Yu. Turkin. RF patent No. 2071116, G 07 C 3/08, 1996.

5. V.D. Grishin, A.N. Timofeev, V.V. Lysak. USSR AS No. 1732364, G 07 S 3/08, 1992.

6. G.N. Vorobiev, V.D. Grishin, A.N. Timofeev. USSR AS No. 1580414, G 07 S 3/08, 1990.

7. A.Ya. Maslov. Operation and repair of communications. WICKA them. A.F. Mozhaysky, 1995, 533 s.

Claims (1)

A device for determining the reliability characteristics of a product containing a comparison unit, the first output of which is connected to the input of the step voltage generator, and the second output is connected to the enable input of the first key, the output of which is the first output of the device, the second input of which is connected to the first input of the adder, the output of which is connected to the second input of the divider, the output of which is connected to the second input of the comparison unit, characterized in that a second key and two delay elements are introduced into it, the first input of the cp block avtoniya is the first input of the device, and the second input through the first delay element is connected to the information input of the first key, the enable input of which is connected to the enable input of the second key, the information input of which through the second delay element is connected to the output of the step voltage generator and to the second input of the adder, and the output is the second output of the device, the second input of which is connected to the first input of the divider.