Guidelines for laboratory work in the discipline. Guidelines for performing laboratory work in the course “reliability of technical equipment” for students in the direction of Laboratory work on the reliability of information systems

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

RYAZAN STATE RADIOTECHNICAL INDUSTRY

UNIVERSITY

FACULTY OF AUTOMATION AND INFORMATION TECHNOLOGY

IN MANAGEMENT

Department of Automated Control Systems

Guidelines To laboratory work by discipline

Reliability information systems

Specialty 071900 --Information systems and technologies

Full-time education

Ryazan 2006

Introduction

Reliability problem technical systems has existed for several decades, and it has become especially acute with the widespread introduction of complex systems. The creation and use of such equipment without special measures to ensure its reliability does not make sense. The danger lies not only in the fact that new complex equipment will not work (downtime will occur), but mainly in the fact that failures in its operation, including incorrect operation, can lead to catastrophic consequences. With this in mind, during the design, manufacture and operation of systems, appropriate measures must be taken to ensure increased reliability of these systems.

The guidelines contain a description of four laboratory works.

In the first laboratory work, the basic concepts and methodology of oriented calculation of the reliability of an electronic unit, for which the reliability indicators of the elements are known, are studied. The electronic unit is considered as an object that cannot be restored during operation. The results of calculating the reliability of electronic components can be used to assess the reliability of a complex of technical means of an information system.

The second laboratory work is devoted to studying the reliability of the system being restored. This topic is traditionally associated with the analysis of the reliability of technical systems, which are restored during operation when failures occur. However, not only a technical device can fail, but also information that, for example, is stored in a database. Bringing the database back to exactly the state that existed before the failure is accomplished using special recovery procedures.

The third lab examines a redundant (duplicated) recoverable system. The redundancy method is widely used in information systems not only at the level technical means, but also at the level of ensuring data safety. One of the responsibilities of an information system administrator is data backup. Having a database backup allows you to restore system functionality if the main data files fail.

When exchanging information between different subsystems, redundancy can be realized through the possibility of using additional communication channels or through organizing multiple transmission of information, etc.

The fourth laboratory work is devoted to studying the effectiveness of the functioning of the restored system, i.e. the degree of its adaptability to perform given functions. Efficiency assessment is important in cases where a complex system, in the event of failure of individual subsystems, continues to function with some deterioration in the quality of operation.

Guidelines for laboratory work are intended for full-time and part-time students in specialty 071900 “Information Systems and Technologies”, studying the discipline “Reliability of Information Systems”.

Guidelines for performing laboratory work in the course “reliability of technical equipment” for students of the field

UZBEK COMMUNICATIONS AND INFORMATION AGENCY

TASHKENT UNIVERSITY OF INFORMATION TECHNOLOGY

FACULTY OF INFORMATION TECHNOLOGY

Department of Computer Systems

METHODOLOGICAL INSTRUCTIONS

To perform laboratory work according to the course

"RELIABILITY OF TECHNICAL EQUIPMENT"

For students directions

5811300-“Service” (electronic and computer equipment)

Tashkent 2008

Guidelines for performing laboratory work on the course “Reliability of technical equipment.”

Rasulova S.S., Kakhkharov A.A. /TUIT. 54 p. Tashkent, 2008.

This paper discusses laboratory work in the course “Reliability of Technical Equipment” and the methodology for their implementation. The main goal of the work is practical familiarization with methods for assessing reliability, with techniques for creating algorithms for studying performance and studying methods for generating tests for digital computer devices (CT). Acquiring skills in using these algorithms when solving relevant problems using computers.

Intended for students studying in the direction 5811300-"Service" (electronic and computer equipment) in the course "Reliability of technical equipment".

Department of Computer Systems.

Table 10. Ill. 17 Bibliography: 8 titles.

Published by decision of the scientific and methodological council of Tashkent University information technology.

Reviewers: Prof., Doctor of Technical Sciences Sagatov M.M. (TSTU)

Doctor of Physics and Mathematics Azamatov Z.T. (Head of the Department of State Committee for Science and Technology)

©Tashkent University of Information Technologies, 2008.

REQUIREMENTS FOR LABORATORY WORK

1. 
   Before receiving an assignment, the student must repeat the relevant sections of the “Reliability of Technical Equipment” course, read the literature indicated in the work, study materials related to the peculiarities of solving a given problem on a computer, and prepare calculation and theoretical materials for each item “Assignment and procedure for performing the work.” Before starting work, you must present your work materials to the teacher to check them for discussion.
2. 
   A reliability calculation task usually contains a structural diagram of the object of study, for which it is necessary to determine the value of a given reliability indicator, the law of operation of the system in the event of failures of its components, as well as the reliability characteristics of the elements of the object.
3. 
   Having prepared the initial data in accordance with the characteristics of the study block diagram, the required accuracy of the research, the capabilities of universal algorithms, the student presents them in a form convenient for entering into a computer.
4. 
   After checking the correct representation of the source data, the student configures the appropriate model to solve a specific problem. While working in interactive mode, it makes corrections to the source data in order to obtain the specified values ​​of reliability indicators of the object under study.
5. 
   The testing task usually holds digital circuit implementing an arbitrary function for which it is necessary to find fault tests of the type X/o or X/1 using various ways building tests.
6. 
   Having checked the correctness of the presentation of the initial data, the student, using the specified test generation method, decides specific task on the computer.
7. 
   After completing the work, obtaining the results, and analyzing the solutions obtained, each student is required to submit a neatly prepared report to the teacher.

GENERAL INFORMATION TESTING TASKS

Testing tasks. Features of the organization of the information processing process, the introduction of new technologies at the production stage and original circuit solutions allow us to highlight modern digital devices(CD) into a special class of devices that require the development of special procedures for determining their performance. This, however, does not mean a rejection of the currently widely used methods for detecting and troubleshooting control units.

An approach based on the optimal use of the results obtained in recent years in the field of control and technical diagnostics, taking into account the features of the architecture and operating logic of the control center.

By testing the control unit we mean the process of establishing the serviceability or operability of a device using certain input influences and analysis of the corresponding output influences and analysis of the corresponding output reactions.

Testing is one of the main diagnostic procedures, the tasks of which are to determine the technical condition of the monitored object and, in case of its inoperability, to detect and localize faults.

The set of input action and the corresponding output reaction is called a test, and the ordered sequence of tests is called a test program. The control center procedure consists of developing a test program, subsequent application of input influences to the controlled device, observation of output signals and analysis of the results obtained in order to establish the suitability of the product.

The monitoring procedure provides complete (incomplete) control of the control center if it detects any (does not detect at least one) malfunction of the class of violations under consideration. Complete control is one of the main requirements for the device test program being developed. Another is the length of the test program. Depending on what is the information for creating a control center test program, two controls are distinguished: functional and structural.

In functional control, the control center functioning algorithm is used as the initial information for constructing tests. The need for functional control is caused by the lack of complete information about the causes of failures, the increased complexity of the controlled device, reduced requirements for complete control, etc. Functional control most often used by CC users.

Methods for constructing tests for structural control are focused on schematic diagram(structure) of the control center being checked. They are used at the production stage. These methods have now been most fully developed and have proven themselves in practice in monitoring and diagnosing devices consisting of types of replacement elements. Structural methods provide complete control.

Laboratory work No. 1

RESEARCH OF THE RELIABILITY OF SYSTEMS WITH A BRANCHED STRUCTURE

Purpose of the work– familiarization with the methodology for studying the reliability of systems with a branched structure using logical and probabilistic methods.

Statement of the problem: Master the methodology of reliability research computer systems using a universal software model based on the use of a logical-probabilistic display of the reliable behavior of systems, set out in.

Duration of work – 2 hours.

Theoretical information

One of the promising directions is the development of logical-probabilistic methods, the mathematical essence of which lies in the use of logic algebra functions (LOF) for analytical recording of the operating conditions of the system and in the development of methods for transition from FAL to probabilistic functions that objectively express the reliability of this system.

The calculation of numerical values ​​based on the analytical expression for the probability of failure-free operation (FFO) is reduced to performing algebraic operations of multiplication and addition. There are several methods for calculating reliability using logical-probabilistic methods: tabular, circuit-logical, cutting algorithm, orthogonalization.

Universal software model is a software implementation of a computational algorithm that performs a sequence of actions on input data characterizing the system under study. The result of such actions is to obtain a numerical value of such a reliability indicator as the FBG system r for a given time interval T. Using the algorithm under consideration, it is possible to study the reliability of non-recoverable redundant systems with a branched structure.

The input data of the algorithm are the following: number of system elements – n, values ​​of FBG elements for the studied time interval P i, as well as binary vectors X l shortest paths for the successful functioning of the system (SPUF), the principle of obtaining which will be described below. The restrictions that apply to the systems under study when applying the computational algorithm are as follows.

The system can only be in two states: in a state of full functionality ( U= I) and in a state of complete failure ( Y = 0). It is assumed that the action of the system deterministically depends on the action of its elements, i.e. is a function X 1 , X 2 ,..., X i ,..., X n , which, in turn, can also only be in two incompatible states: full functionality ( X i = 1) and complete failure ( X i = 0). Specific values ​​of binary variables X i determine the state of the system or the so-called vector of system states X = (X 1 , X 2 ,..., X i ,..., X n), which is the main parameter with which the computational algorithm operates.

In order to specify the performance function necessary to calculate the reliability indicator, it is necessary to construct a logic algebra function that connects the state of the elements with the state of the system. To obtain it, one should use the concept of a CPUF, which represents such a conjunction of its elements, none of the components of which can be removed without disrupting the functioning of the system. Such a conjunction is written as the following FAL: R l = Λ X i , Where i belongs to many numbers KR l, corresponding to this l- way.

In other words, the system’s CPUF describes one of its possible operational states (PC), which is determined by the minimum set of operational elements that are absolutely necessary to perform the functions specified for the system. Thus, for the system under study it is necessary to determine all d possible KPUF and then the system operability function is written as follows:

those. in the form of a disjunction of all available CPUFs.

When determining the reliability indicator noted above, it is necessary to calculate a probability function of the form

P [U(X 1 ,…, X n) = 1] = R c

In this case, the main difficulties arise due to the repeated form of FAL, because the same operational states will be taken into account as many times as they are associated with CPUFs.

Let's consider two computational algorithms based on the logical-probabilistic method and select the most effective one for a given version of the system.

The procedure for calculating using the first algorithm

For a given version of the system, the set of all CPUFs is determined, which are represented in the form of binary words. The number of bits in a word is equal to the number of elements in the system. A bit value equal to 1 means the element is operable; a bit value equal to 0 means the element fails.

An algorithm based on the CPUF forms all possible binary words that define all operational states of the system, selects non-repeating ones and calculates the corresponding probability for each. For example, let's say there is a bridge circuit shown in Fig. 1, consisting of 5 elements, probability of finding i – th element in working condition is equal to P i , the probability of an element being in a failure state is equal to I-P i = Q i .

For a given bridge circuit, the shortest paths are: 11000, 00110, 10011 , 01101.

Rice. 1. Bridge circuit

Each shortest path has associated operational states shown in Table 1. The first digit on the left corresponds to element number one.

Table. 1

KPUF No. BRS	1	2	3	4
1	+11000	+00110	+10011	+01101
2	+11001	+00111	10111	01111
3	+11010	+1110	11011	11101
4	+11011	+01111	11111	11111
5	+11100	+10110
6	+11101	+10111
7	+11110	11110
8	+11111	1111

Thus, 24 codes corresponding to operational states of the system were obtained. However, we see that some of them are repeated in the table columns. Let's exclude duplicate codes from all 24, and then there will remain 16 codes noted in the table. 1 + sign. These 16 codes obtained correspond to all possible operational states of the circuit under consideration. Consequently, the system will be operational when it is in one of the 16 listed incompatible states. If we calculate the probabilities of the system being in each of the 16 states and sum these probabilities, we get the probability that the system is in an operational state.

If the probability of finding i-th non-recoverable element in working condition P i is a function of time, then we obtain the FBG of the system for a given time. This is one of the main indicators of system reliability.

So, in order to obtain the probability value of the system being in one of the operational states, it is necessary to replace one in the corresponding binary word with probability P i , and zero for probability I - P i and multiply these probabilities. For example, for code 11000 this will be the product

The probability of our system being in working condition will then be determined as

Despite the simplicity of implementing this process on a computer, it has a number of disadvantages. The main ones are the requirement for large volume RAM for storing a set of binary words, as well as a rapid increase in the number of searches when comparing binary words and a loss of calculation accuracy with an increase in the number of system elements, since the value 1 - P i is usually small.

The procedure for calculating using the second algorithm

Unlike the first algorithm, in the second the reliability of systems with a branched structure is calculated using the tabular method. The tabular method for calculating system reliability is based on the use of the theorem for adding the probabilities of joint events, which are the elementary conjunctions of the conditions of operability (or inoperability) of systems described in DNF using QPUF.

According to this theorem and expression (1.1), the FBG of the system is calculated by the formula:

Where ρ l & ρ j means the joint occurrence of events related to the KPUF ρ l And ρ j, i.e. elements belonging to the minimum set are in working condition ρ j .

Despite the cumbersomeness of writing formulas, the algorithm for calculating the reliability indicator using it turns out to be simple and easy to program. The tabular calculation method is convenient for two reasons:

• 
  logical variables are automatically multiplied by themselves according to the identity

• 
  many identical conjunctions, the probabilities of which have different signs, are mutually destroyed.

The sequence of steps in the algorithm is as follows:

1. Create a special table in which you need to place n rows (according to the number of elements in the system), indicate the FBG of the elements in the table rows, and write down all possible combinations of conjunctions in the column names ρ i taken one at a time, but two at a time, three at a time, etc.

2. U show the signs of the probabilities of conjunctions alternating in accordance with formula 1.2.

3. Fill in the table with crosses and dashes, crossing out those identical conjunctions that are included in it with different signs.

4. Calculate the probabilities of failure-free operation of the system by multiplying those probabilities in each column ρ i, which are marked with crosses.

Let's consider an example of calculating FBG for a circuit - Fig. 1.

Let's denote:

The occurrence of one or another element in the corresponding conjunctions is marked with a cross in the table. Probabilities of conjunctions – ρ 1 -ρ 4 And ρ 11 - ρ 14 are taken with a (+) sign, the rest with a sign
(-). So, the FBG for the scheme under consideration is equal to

Task options

Table 2

Options FBG(P2)	1	2	3	4	5	6	7	8	9	10
P1	0,96	0,95	0,96	0,94	0,93	0,98	0,95	0,85	0,9	0,97
P2	0,94	0,945	0,97	0,96	0,95	0,85	0,99	0,9	0,92	0,95
P3	0,95	0,95	0,98	0,99	0,94	0,96	0,98	0,92	0,95	0,98
P4	0,98	0,96	0,95	0,98	0,96	0,93	0,96	0,93	0,92	0,96
P5	0,96	0,95	0,96	0,95	0,98	0,98	0,97	0,9	0,91	0,95

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

STATE EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

"KOVROV STATE TECHNOLOGICAL ACADEMY"

Department A and U

METHODOLOGICAL INSTRUCTIONS

"Reliability of control systems"

UPDATED CALCULATION

QUANTITATIVE INDICATORS OF RELIABILITY.

Kovrov, 2007

LABORATORY WORK No. 2

REFINED CALCULATION OF QUANTITATIVE INDICATORS OF CONTROL SYSTEMS RELIABILITY.

Purpose of the work: mastering methods for calculating quantitative reliability indicators, refined based on the results of detailed design, manufacturing and testing of prototypes.

1. GENERAL INFORMATION

This type of calculation is carried out in order to clarify the reliability assessment carried out at the stages of preliminary and technical design.

Based on the results of the previous stages of design and testing of prototypes, there should be:

Tests of prototypes of the product were carried out in order to determine the operating conditions and modes, taking into account the selected methods of protection from external influencing factors to ensure the specified reliability;

Calculation maps of operating modes of components and elements, updated based on test results, as well as thermal modes of their operation (overheating), taking into account measures taken cooling product blocks;

There are known functional dependences of failure rates of components and elements on electrical load, temperature, mechanical influences and other operating conditions.

2. TASK FOR WORK

Carry out a refined calculation of quantitative indicators of product reliability under given specific real operating conditions. Initial data for the fundamental option electrical diagram the product and its operating conditions, as well as the list of calculated reliability indicators are specified by the teacher (the options correspond to the options for the assignment for laboratory work No. 1).

3. MATHEMATICAL MODELS FOR CALCULATING FAILURE RATES

3.1. Mathematical model to calculate failure rates of resistors, capacitors, semiconductor elements, transformers and coil products Under real operating conditions:

font-size:13.0pt;line-height:150%"> (1)

where, λ0 is the nominal value of the failure rate of the elements and CI elements included in the product, corresponding to the electrical load coefficient Kn = 1 and the ambient temperature T 0C = +20 0C.

The values ​​of λ0 are selected from the corresponding tables:

For resistors - table 1;

For capacitors - table 2;

For semiconductor devices - table 3;

For transformers and winding products (chokes, inductors, etc.) - Table 4.

a i = f (K n ,Тhttps://pandia.ru/text/79/296/images/image003_85.gif" width="12" height="23 src=">.gif" width="12 height=23" height="23" >0С in the element zone. The coefficient values ​​are selected from the corresponding tables ( i =1,2,3,4)

a1 – correction factor for determining λe of resistors is selected from Table 5;

a2 – correction factor for determining λe of capacitors is selected from the table. 6;

a3 – correction factor for determining λe of semiconductor devices is selected from Table 7;

а4 – correction factor for determining λe of transformers and winding products (chokes, inductors) is selected from Table 8;

Ki – correction factor that takes into account the actions of external influencing factors and is selected from the corresponding tables ( i =1,2,3,4)

K1, K2 – correction coefficients that take into account the effects of vibrations and shock loads on elements and CI, respectively; the values ​​of these coefficients are selected from the table. 9;

K3 – correction factor taking into account humidity and ambient temperature, selected from Table 10;

K4 – correction factor taking into account the change in λe depending on the height above sea level, selected from Table 11.

3.2. Mathematical model for calculating relay failure rates:

font-size:13.0pt;line-height:150%">where, λ0’ is the basic value of the relay failure rate, which is calculated by the formula:

Formula (3) is used for relays with winding wire diameter d ≥ 0.35 mm;

Formula (4) is used for relays with winding wire diameter d< 0,35 мм.

N – total number of contact pairs;

n – number of contact pairs involved;

λ0 is the nominal value of the relay failure rate, selected from Table 12.

Ki – correction factor taking into account the effects of external factors. Coefficient values Ki (i = 1, 2, 3, 4) is selected accordingly from tables 9, 10, 11.

KF – coefficient that takes into account the switching frequency of the relay when operating in the product; the values ​​of this coefficient are selected from Table 13.

3.3. Mathematical model for calculating failure rates integrated circuits:

font-size:13.0pt;line-height:150%"> (5)

where - the basic value of the failure rate of integrated circuits is calculated using the following formula:

https://pandia.ru/text/79/296/images/image009_38.gif" width="136" height="44 src="> (6)

where EN-US" style="font-size:13.0pt;line-height:150%">n– the number of external involved pins of the microcircuit;

Ki – (i

3.4. Mathematical model for calculating the failure rate of switching elements (toggle switches, switches, buttons):

font-size:13.0pt;line-height:150%"> (7)

where λ0 is the nominal value of the failure rate, selected from Table 14;

K f – coefficient depending on the switching frequency, the value of this coefficient is selected from Table 15;

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

3.5. Mathematical model for calculating connector failure rates:

font-size:13.0pt;line-height:150%"> (8)

where λ0 is the nominal value of the connector failure rate, selected from Table 16;

Kcs – coefficient depending on the number of joints – divisions, is selected from table 17;

Kkk is a coefficient depending on the number of contacts involved; the value of this coefficient is calculated by the formula:

Kkk = (9)

where n – number of contacts involved;

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

3.6. Mathematical model for calculating the failure rate of electrical cables, wires, cords:

font-size:13.0pt;line-height:150%"> (10)

where λ0 is the nominal value of the failure rate of cables, wires, cords, selected from Table 18;

L – total length of cable (wire, cord); for products with L ≤ 3 m is allowed to be accepted L = 1 m;

Kf is a functional coefficient, the value of which can be determined by the formula:

Kf = (11)

where Еа – conditional activation energy, kJ/mol;

R g = 8.3144 – universal gas constant, J/Grad mol;

K t – temperature coefficient depending on operating temperature environment in equipment; determined by the formula:

Kt = (12)

where tp – operating maximum temperature in the equipment (product), 0C;

t b – base temperature equal to 25 0C at or 100 0C at (by cable type).

As a rule, the maximum temperature of the product, taking into account overheating, is in the range of 70 0C - 80 0C.

The value of the conventional activation energy varies from 40 to 120 kJ/mol (average) and has a level of

Еа font-size:13.0pt;line-height:150%">Taking into account the specified limitations for practical calculations in formula (10) at EN-US" style="font-size:13.0pt;line-height:150%" >tp = 70 0C, Kf = 200 at tp = 80 0 C and Kf = 600 at tp = 100 0 C

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

3.7. Mathematical model for calculating failure rates of connections (solder):

font-size:13.0pt;line-height:150%"> (13)

where λ0 is the nominal value of soldering failure rate;

λ0 = 0.015 10-6 1/hour

p –number of rations in the product;

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

3.8. Mathematical model for calculating the failure rate of fuses:

font-size:13.0pt;line-height:150%">where λ0 is the nominal value of the fuse failure rate;

λ0 = 0.5 10-6 1/hour

CT – thermal coefficient, depending on the temperature of the working environment surrounding the fuse; the values ​​of this coefficient are selected from table 19;

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

3.9. Mathematical model for calculating the failure rate of electrical machines:

font-size:13.0pt;line-height:150%"> (15)

where λ0 is the nominal value of the failure rate of electrical machines, selected from Table 20;

а4 – correction factor for determining λ of electrical machines, selected from Table 8;

Δλ – additional failure rate of electrical machines depending on the rotation speed, selected from Table 21;

Ki – (i = 1, 2, 3, 4) are selected respectively from tables 9, 10, 11.

4. CALCULATION PROCEDURE

4.1. The basic electrical circuit of the product is analyzed from the point of view of its elemental and quantitative composition, which is divided into K groups of equally reliable elements, pieces in each group.

It is assumed that the product in question has a sequential connection diagram for reliability calculations.

The results of the analysis are entered in table 22, columns 1 – 4.

4.2. In accordance with the nomenclature used element base From tables 1, 2, 3, 4, 12, 14, 16, 18, 20, the nominal values ​​of failure rates of elements and components (CI) used in the product are selected.

The selected nominal values ​​of CI failure rates are entered in the table. 22.

4.3. Based on the available load coefficients KN (column 6) and the operating temperature (column 7) of the environment surrounding the element (taking into account overheating), for each element and KI the values ​​of correction factors a are selected from tables 5, 6, 7, 8 i = f (KH, TEN-US">C)

i = 1, 2, 3, 4.

4.4. From tables 9, 10, 11, the values ​​of the K coefficients are selected for each element and CI i depending on the specified operating conditions (conditions of operating severity).

Selected K coefficient values i(i = 1,2,3,4) are entered in columns 9 – 12 of the table. 22.

4.5..gif" width="21" height="25 src=">= const)

font-size:13.0pt;line-height:150%">The calculation results are entered in column 16 of table 22.

4.6. The total failure rates are determined for each group of equally reliable elements and CIs, and the calculation results ( nj · λ e i ) are entered in column 14 of table 22. (where is the number of equally reliable elements in the group, https://pandia.ru/text/79/296/images/image029_9.gif" width="21" height="24 src="> = const - failure rate of each element in j-th group)

4.7. For a relay, the operational failure rate values ​​are calculated using formula (2). In this case, the values ​​of the nominal failure rates are selected from Table 12. Depending on the diameter of the winding wire, the basic values ​​of the relay failure rates are calculated font-size:13.0pt;line-height:150%">K coefficient values F are selected from table 13. Correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.8. For toggle switches, switches, and buttons, the operational failure rate values ​​are calculated using formula (7). The values ​​of the nominal failure rates are selected from Table 14. The values ​​of the K coefficients f are selected from table 15. Correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.9. For integrated circuits, the operational failure rate values ​​are determined by formula (5). In this case, the basic value of the failure rate is calculated using formula (6); - selected from table 3 (low-power transistors).

4.10. For connectors, the operational failure rate values ​​are determined by formula (8). In this case, the values ​​of the nominal failure rate are selected from Table 16,

The values ​​of the coefficients Kkc are selected from table 17. The values ​​of the coefficients Kkk are calculated using formula (9).

The values ​​of correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.11. For soldering (connections), the operational failure rate values ​​are determined by formula (13). In this case, the value of the nominal failure rate is taken equal to λ0 = 0.015 10-6 1/h.

The values ​​of correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.12. For fuses (fuse links), the operational failure rate values ​​are determined by formula (14). In this case, the value of the nominal failure rate is taken equal to λ0 = 0.5 10-6 1/h.

The values ​​of the CT coefficient are selected from Table 19 depending on the temperature values ​​of the working environment surrounding the fuse.

The values ​​of correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.13. For electric machines, the value of operational failure rate is determined by formula (15).

The nominal failure rates are selected from Table 20.

The values ​​of the correction factor a4 are selected from Table 8 depending on the ambient temperature. The additional failure rate Δλ, as a function of rotation speed, is selected from Table 21.

The values ​​of correction factors K1, K2, K3, K4 are selected from tables 9, 10, 11.

4.14. The results of calculations of the operational failure rates of elements and CIs, performed in accordance with algorithms 3.7 – 3.12, are entered in column 13 of Table 22.

4.15. The total failure rates for each group are determinednjelements (3.7 – 3.12) and calculation results (nj· λ e i ) are entered in column 14 of table 22.

4.16. The failure rate values ​​of the product as a whole are calculated by summing all the values ​​in column 14 of table 22:

5. REPORTING

The results of the refined calculation of product reliability indicators are presented in the form of a count containing:

5.1. Assignment: Option number __. Operating conditions: by type of object, for example, “airplane”

temperature range_______________________________________________

vibration loads __________________________________________

shock loads _______________________________________________

altitude______________________________________________________________

humidity_____________________________________________________

List of reliability indicators to be calculated_______________

5.2. Schematic electrical diagram of the product and list of elements.

5.3. Table 22, containing initial data (results of analysis of the electrical circuit diagram of the product, values ​​of load factors Kn, ambient temperature for each element and CI), intermediate results of calculations, values ​​of correction and other coefficients, final results of calculations of group failure rates (column 14).

5.4. The nomenclature of determined quantitative reliability indicators (required reliability indicators λс, Т, P(t)).