SU458833A1 - Device for determining reliability by gradual failures - Google Patents

Description

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The invention relates to instrumentation engineering and is intended to automate the process of investigating the reliability of gradual failures of electronic devices using physical modeling techniques.

Devices are known that automate the process of investigating the reliability of functional units of electronic devices using f.physical modeling methods, which include a brute force block of implementations, a dial-in field, a control block, and a computation block (for example, an electronic computer).

However, known devices are characterized by a large amount of physical model testing to obtain a given accuracy and reliability of the results of a reliability study, difficulties in modeling the required random laws for the distribution of internal parameters in the process of testing a physical model, obtaining random combinations of internal parameters with a given probability, and analyzing statistical data. z between internal and output parameters.

The proposed device differs from those known in that it additionally includes a series-connected random time interval generator, a multi-channel converter of a random number of pulses, and a channel switch. The outputs of the channel switch are connected to the unit for switching internal parameters of ICD of digital devices. A random time interval generator is connected to a channel switch that is connected to the measurement unit, and the output of the calculation unit is connected to a channel switch.

These differences make it possible to increase the accuracy of the results of the research. Reliability, reduce the laboriousness, and investigate the statistical relationship of the output parameters with the internal ones.

FIG. 1 shows the scheme of the proposed device; .on FIG. 2, a – d — timing diagrams for the operation of the device.

The device contains a generator of 1 random time intervals, generating random time intervals T (FIG. 2, d). distributed according to an equal law (Fig. 2, e) in the normalized time interval m (Fig. 2, e).

The generator is connected to the input of a multichannel converter 2, which converts random time intervals into a random number of pulses, the distribution law of which is set by the operator.

The converter 2 is connected to the switch 3, which produces the switching of the channels of the converter 2, as well as the channels of the switching unit 4 of the internal parameters with which it is connected. Block 4 is associated with a physical model 5, on which the test device is mounted. By this connection, commands are issued for switching the values of the internal parameters of the physical model 5, which is connected to the measurement unit. Unit 6 measures the output parameters of the device under study, converts them into a digital code, and n enters into unit 7 the computations with which it is associated. Block 7 produces a fixation and processing of the values of the output parameters in each experience according to a given program. The computing unit is connected to the 3-channel switch. This connection receives signals that determine the end of processing the values of the output parameters of the previous experiment.

The Katsal switch 3 is also connected to the generator 1 and to the converter 2. The signals for switching the switch 3 are received via the first connection, and the channel 2 of the converter 2 is switched over to the second connection. The converter 2 is connected to the measurement unit 6. This link provides information on the values of the internal parameters in each experiment for entering it into the computing unit 7, which is necessary to determine the statistical relationship between the internal and output parameters of the devices under study.

The proposed device works as follows.

The converter 2, the switch of the 3 channels and the block 4 contain on each of the n channels in each. This number determines the number of internal parameters that can be varied during testing. Each internal parameter Xg (r 1,2, ..., and) in the physical model 5 is represented in a given interval mk 1-- max set m of a certain number of ki discrete values (X, Xzi, V This number is determined by limits of variation and the required discretization of internal parameters. Depending on the order of distribution of the internal parameter t-ro in a given interval, each discrete value of this internal parameter should appear with a certain probability when conducting tests: Xi - with probability Pii, 2i - with probability, with - with probability P / if (Fig. 2, a).

This happens as follows.

The generator 1 fixes the beginning and the end of the time interval m (Fig. 2, d). In this interval, a pulse appears at a random moment of time (Fig. 2, d). The random temporary diptep that is generated by the Operator 1 is the time interval T (Fig. 2, d) from the moment this appearance of the impulse until the end of the time interval t.

Thus, random time intervals Γ can have a duration from 0 to m. The law of distribution of the random variable T is equal to each other (fig. 2, c). With the help of i-ro k.a.nala converter 2 ,, time interval t is divided by ki time intervals tif, t2t, ..., thi (Fig. 2, b). These durations are chosen to be proportional to the required probability of occurrence of discrete values of the i-ro values of the internal parameter, namely 2g t-H2, ..., tk r-Pki. The end of each time period is recorded by the appearance of the pulse (Fig. 2, b). These pulses can pass through the switch of 3 channels to the corresponding channel of block 4 only for a random time interval T. Thus, a single pulse appears at the output of the j-ro channel of switch 3 if the pulse fixes 1, and the beginning of the random time interval T, falls into the time interval, two pulses, if this impulse falls into the time interval 2; etc. That is, the number of pulses appearing on the output of the rth channel of converter 2, in each experiment depends on the time interval j; (, 2, ..., ki) impulse that fixes the beginning random time interval T. With an even distribution of the random variable T, the probability that the impulse that fixes the beginning of T falls in the time interval tjf is proportional to the duration

of this gap, i.e. Pj, -. Thus, the assignment of the required law of the distribution of the number of pulses at the output of the converter 2 in each channel is reduced to the division of the time interval τ by the time intervals of the corresponding duration in each channel. Obviously, pr.and this

A, + 2i + ... + Ji + ..- + 4, T.

The required distribution law in each channel of the transducer 2 is described in the above way, it is calculated by the controller before the test begins.

The commutation of the values of the internal parameters of the device under investigation in each experiment is carried out as follows. The random time interval T from the generator 1 enters. The first channel of the converter 2, where it is converted into a random number of i.pulses. These pulses through the switch 3 channels are transmitted to the first channel of block 4, which switches the corresponding discrete value of the first internal parameter, and the sequence number of the switched on discrete value of the first internal parameter corresponds to the number of pulses received on the first channel of block 4.

The impulse, fixing the end of the time interval t, from the generator 1 enters the switch of 3 channels and switches it to one step. In this case, the next random time interval T from generator 1 comes already on the second channel of converter 2, where it is converted into a random number

pulses that go to the second channel of block 4, as a result of which the corresponding discrete value of the second inner pair will be switched on, etc. until the discrete values of all n internal parameters are switched on. This completes the switching of the internal parameters for one experiment. At the end of the commutation, a pulse arrives from the coaxial switch of the 3 channels to the measuring unit 6, which is the signal for starting the measurement and entering the block 7 for calculating the values of output parameters corresponding to this experience. After the end of the measurement and the input of all output parameters to the computing unit, a pulse arrives at the switch 3. This is the command to implement the next one. When analyzing the statistical connection between input and output parameters and parameters from converter 2 through block 6, in block 7 of calculation, information is entered on the value of the corresponding internal parameter in each experiment. Entering into the block of calculations the values of the virtual and output parameters in each experiment allows production according to the program,

embedded in the block of calculations, the study of the statistical relationship between the input and output parameters (for example, to build the regression curves of the output parameters on the internal).

Subject invention

A device for determining reliability by gradual failures, containing serially connected switching unit of internal parameters, physical model, measuring unit and computing unit, characterized in that, in order to improve the accuracy of the results, it additionally contains a series connected random time interval generator, which is often used. a random converter of a random number of pulses and a channel switch, the outputs of which are connected to the switching unit of internal parameters, the measuring unit and Go-channel converter, the output of which is connected to the measuring unit, moreover, the random time interval generator and the computing unit are connected to a commutator.

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