Mathematical modeling of vibrodiagnostics latent defects in the construction of electronic means
The article discusses the application of statistical modeling for the durability prediction of electronic equipment. Durability indicators are one of the important characteristics of onboard electronic equipment of spacecraft with long terms of active existence. The purpose of the study is to improve the quality of design work by improving the method of calculating the life of electronic equipment, taking into account the probabilistic characteristics of the life components of its electronic components. The object of the study is a typical procedure for calculating the life of electronic equipment at the design stage from data on the characteristics of the durability of electronic components. The subject of the study are methods, models and algorithms applicable to the analysis of the design level of the durability of electronic equipment. To study the effectiveness of statistical modeling, software was developed and the reliability of its work was tested. With the help of this software, computational experiments were carried out. Comparison of the results of statistical modeling and calculations by a typical methodology made it possible to identify a number of significant limitations of the deterministic method. In the standard methodology, it is assumed that the variation coefficient of life is a constant for all electronic components. But the analysis of Data Sheet of electronic components has shown that the values of the variation coefficient can be different for electronic components of different types. The calculations have confirmed the need to take into account the values of the variation coefficient of life in predicting the durability of electronic equipment. In addition, in the standard methodology it is assumed that the life of electronic equipment that contains electronic components with the same life values will be equal to the life of electronic equipment that contains only one such electronic component. Computational experiments have shown that the life of electronic equipment that contains electronic components with the same life values will be less than the life of electronic equipment that contains only one such electronic component. Based on the studies, the scope of the standard methodology was determined and the effectiveness of statistical modeling was proved. However, the results obtained by the statistical modeling method should be corrected by the results of the tests and the controlled operation of electronic equipment.
In order to assess the level of electronic means reliability, it is necessary to have a methodology for analyzing the results of calculating its reliability indicators, such as the probability of failure-free operation or mean time between failures, which allows to evaluate which of the parameters most strongly affects the final value of the failure rate of electronic component particular type. As a result of analyzing the reliability of electronic mean all-levels components, the engineer should obtain the values of the reliability indicators, the boundary values of the controlled parameters, and also give recommendations on certain changes necessary to improve the reliability, thereby implementing the reliability management methodology. This technique, in contrast to the already known ones, will allow analyzing the calculated values of the indicators and using the relative sensitivity function to determine the contribution made by specific parameters: temperature, element ratings, their operating voltage, current, power, tolerance level, while previously contribution was estimated by the numerical value of a separate correction factor. Application of the developed methodology for analyzing the results of calculating the reliability of electronic means allows to specify the recommendations for changing parameters in order to improve the reliability of the elements that make up the product in question.
This paper presents a system that automates the process of ensuring testability in the design of electronic equipment. Developed and presented algorithms of basic modules. Discussed in detail module for selecting diagnosed elements.
This article describes how to make the block navigation system redundancy scheme and design in the form of built-in emulator to detect latent defects, to experimental verification of the developed method of vibration diagnostics.
Authors are proved need of contact control methods application of electronic means elements when carrying out thermal diagnosing in the closed constructive volume. The method of the error calculation brought by the sensor at measurement of element temperature is described. In article topological thermal models of electronic component mounted on the printed circuit board and a pair of electronic component-sensor are presented and investigated in thermal modeling subsystem ASONIKA-T. This models are proposed to use in a new calculate method of error introduced by the sensor. The authors done the experimental check of the presented calculate method. The creation stages of thermal processes models are described in detail. In article is proved that the developed topological models and method fully meets requirements. The conclusion is drawn that their use in the process of electronic means thermal diagnostics will allow to increase the accuracy of temperature measurements due to compensation of the systematic error brought at measurement by the contact thermal sensor. As a result it will positively affect the reliability of definition of defective electronic components and the reliability of electronic means.
Indicators of maintainability of modern electronic devices greatly depend on the characteristics of reliability of electronic components. The impact of catastrophic electrical overstress due to electrostatic discharge can lead to failures of integrated circuits, which are widely used in electronic tools. The article considers the issues of assessing the impact of electrostatic discharges on the performance of maintainability of electronic means.