Грачев Николай Николаевич

The Prediction of Contact Radio Interference in the Tasks of Ensuring Electromagnetic Compatibility of Radioelectronic Means on Mobile Objects

2023 · CHAPTER · en

This article discusses the forecasting of contact radio interference, which is an essential aspect in maintaining the necessary electromagnetic compatibility level of electronic devices installed in mobile objects. The presented algorithm for predicting contact radio interference makes it possible to expand the possibilities in the design of radio communication systems in the presence of a variety of electronic devices on mobile objects. After analyzing the methods of predicting contact radio interference, recommendations were developed to reduce the impact of this type of interference. Contact radio interference is a type of interference that occurs due to the reemission of a secondary electromagnetic field from mobile conductive structures containing detachable circuit connections. The use of uneven spectral density of contact noise makes it possible to correctly distribute the frequencies of radio equipment, placing the receiving frequencies in areas with low spectral density of contact noise.

Review and Analysis of Methods for constructing Mathematical Models of Electrical Contacts for Predicting of Contact Radio Interference on Mobile Objects

2022 · CHAPTER · en

STUDY OF THE MECHANISMS OF CONTACT RADIO INTERFERENCE ON MOVING OBJECTS USING PROBABILISTIC CHARACTERISTICS

2022 · CHAPTER · en

Within the framework of this article, the results of a study of the mechanisms of formation of contact radio interference from mobile structural elements of radio electronic means using probabilistic characteristics are presented. Obtained results allow to analyze the spectral composition of contact radio interference and can serve as a basis for the construction of effective algorithms for predicting the levels of contact radio interference to ensure inter-system electromagnetic compatibility of elements of radio electronic systems of the required noise immunity.

MОDЕL ОF АDАPTIVЕ MАTCHЕD FILTЕRING UNDЕR THЕ IMPАCT ОF NАRRОWBАND INTЕRFЕRЕNCЕ

2022 · CHAPTER · en

Оnе оf thе mоst dеstructivе typеs оf intеrfеrеncе is strоng nаrrоwbаnd intеrfеrеncе thаt еxcееds thе lеvеl оf usеful signаls. This prоjеct аttеmpts tо implеmеnt аn аlgоrithm thаt cаn еffеctivеly supprеss nаrrоwbаnd intеrfеrеncе whеn sеlеcting usеful signаls frоm thе bаckgrоund оf nоisе. Tо аchiеvе this gоаl, wе prоvidе а mаthеmаticаl mоdеl оf аn аdаptivе mаtchеd filtеr fоr impulsе signаls. Hеrе, thе mаin оptimizаtiоn critеriоn is thе mаximum SNR - signаl / (intеrfеrеncе + nоisе) rаtiо аt thе оutput оf thе аdаptivе mаtchеd filtеr. Thе rеsults оf cоmputеr simulаtiоns whеn thе vаluе оf thе intеrfеrеncе pоwеr аnd thе аmоunt оf аctivе intеrfеrеncе аrе diffеrеnt shоw thаt thе prоpоsеd filtеr supprеssеs аll thе intеrfеring signаls with high еfficiеncy

Investigation of the Characteristics of the Transient Electrical Resistance of Contacts in the Designs of Radio Electronic Devices in the Conditions of the Formation of Contact Radio Interference

2021 · CHAPTER · en

The article discusses the characteristics of the total transient electrical resistance of the contact. The coefficients of the influence of the active and reactive components on the contact impedance are estimated. The dependences of the active and reactive components of the total electrical resistance of the contact on various factors are shown. The studies of the behavior of contact resistances of structural elements carried out in this work make it possible to predict the level of contact interference to radio reception in the future. This is due to the expansion of the spectrum of re-emitted electromagnetic radiation, which occurs due to the irradiation of structural elements with standard devices emitting electromagnetic waves.

Method for Transmitting Information underConditions of Excess of Interference Level over Useful Narrowband Signal

2021 · CHAPTER · en

There are various methods for suppressing radio interference in communications. In particular, interference exceeding the useful signal level. However, these methods in most cases are based on the parameters of the interference in the spectrums' range, the occurrence's time, the action's direction, polarization, etc. It is known that radio systems with a single receiver do not have effective suppressions' means of powerful broadband interference. In addition, there are fundamental limitations of single-channel information transmission systems formulated in the Shannon-Hartley theorem. We have developed a digital signal processing algorithm. It suppresses radio interference and selects a narrowband useful signal. This algorithm is based on the method of spatially spaced two-channel synchronous reception. The research results show high efficiency. The theoretical model allows error-free transmission of information with a signal-tonoise ratio up to minus 26.5dB. This method will significantly improve information transmission systems for their key parameters. These include the frequency range used and noise immunity.

Analysis of functional parts and technological software of the control device for a two-phase synchronous electric motor

2021 · CHAPTER · en

This article analyzes the functional parts and technological software for the developed device for a control of a two-phase synchronous electric motor. An experimental model of a control system for a two-phase synchronous electric motor and software for its operation were designed. The device consists of a source of driving action, a microcontroller that outputs signals to drivers that perform the role of converting the output signals of the microcontroller, filters that smooth out ripples of current flowing through the motor windings, a power source and a two-phase synchronous electric motor. Based on the results obtained, one will plane to create prototypes and conduct their experimental studies in order to further introduce the development into production.

The assessment of the impact of contact radio interference on a communication radio engineering system.

2021 · CHAPTER · en

This article deals about the analysis of works devoted to the issue of contact radio interference and the assessment of their impact on the device was carried out. This analysis was carried out as a preparatory stage for conducting a study to assess the impact of contact radio interference on a communication radio engineering system. An interface has been developed that allows the calculation of the module and phase of the electric contact transmission coefficient model for the inductive, capacitive branch and the full transmission coefficient model.

Portable gamma radiation detector

2021 · CHAPTER · en

The article presents the results of research on the creation of a device for monitoring the radiation background of the environment. A distinctive feature of the developed device is its compactness and high reliability of results. The device registers ionizing radiation and, via a USB port, transmits the processed information to a personal computer or laptop to obtain amplitude spectra of ionizing radiation for the purpose of their further processing and interpretation.

Local computer network data protection device with voice warning of unauthorized access

2021 · CHAPTER · en

This article presents a hardware-software complex for monitoring a LAN with voice audio notification of unauthorized access, developed and used to protect a local area network from unauthorized access. The process of designing a device, the choice of the main components of the device, the selection of auxiliary functional modules, the choice of the system software part and the development of the applied software part of the device are considered. A brief overview of the capabilities of the developed device is carried out.