2021 International Seminar on Electron Devices Design and Production (SED)
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 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.
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.
The research provides a review and analysis of the existing mathematical model of the pumping flashtubes operational failure rate. They are used in various spheres of human activity, such as: industry (laser welding, balancing devices), medicine (laser devices, endoscopes, blood analyzers), photography (high-speed cameras). A computational assessment was carried out using a decision support system, which makes it possible to numerically determine the importance of the factors considered in the work in assessing the operational failure rate. As a result of the study, the main parameters have been determined that have the greatest impact on the pumping flashtubes dependability. Mathematical models considering these parameters have been identified. Reliable mathematical model is proposed, suitable for evaluating the dependability characteristics of pulsed pump lamps.
Automation of control methods of necessary requirements fulfilment or non-fulfilment while ensuring dependability and quality for wireless devices (WD) are necessary at design stages. However, this approach is not used in enterprises. Companies are limited only to expert assessment (non-automated external audit) and assessment of efficiency private criteria in the quality management system (QMS). The existing statistics of failures of radio engineering devices installed on unmanned automatic spacecraft indicates that there are shortcomings of ensuring the dependability and quality of the WD strategy. Therefore, in this paper, the method of dependability assessment of the WD considering the quality management system is proposed. The paper presents a mathematical model of dependability assessment of the WD considering not only the categories of the WD failures but also the private criteria contribution of the QMS functioning efficiency. Automation of the method is achieved by using the developed software.
The article studies the mutual influence of electrical and thermal processes due to their simultaneous occurrence in the printed circuit assemblies of optoelectronic devices (OEDs) in real operating conditions. An increase in the accuracy of computer modeling of electrical and thermal processes can be achieved by switching from the separate modeling of these processes used in engineering practice to their joint simultaneous modeling according to the proposed unified integrated electrothermal model. The authors use the existing in physics electrothermal analogy of mathematical descriptions of these processes. The resulting loads of heat dissipations power and temperatures of electrical radio products placed on the OED printed circuit boards makes it possible to identify hidden potential failures in them during design. When using integrated digital twin, it is possible to identify pre-failure situations during the operation of the OED.
The last decades have witnessed rapid IoT technologies development, which provided ubiquitous human-computer interactions. Building intelligent systems of various types, among which emotion recognition systems, is important challenge nowadays. Especially pressing problem is to build a real-time portable system which can be embedded in low performance hardware. We propose a high accuracy emotion recognition system, which can be deployed on a single board Raspberry Pi computer to perform real-time recognition of 4 facial expressions: neutral, angry, surprised, and happy. Recognition pipeline is divided into two main stages: human face detection and facial expression classification. Both stages are performed by deep neural networks with simple yet effective design. Several optimization techniques, such as weights quantization and model tracing, were applied after model training, to gain extra execution time reduction. The introduced system is lightweight and fast, is executed locally on a cost-effective single board computer, and requires minimum resources to make and transmit predictions, what makes proposed system an effective IoT device.
This article studies the operation of an optical sensor with a cylindrical measured surface. Various options for positioning the sensor are considered. The study provides an estimation of the influence of the radius of the cylindrical reflective surface on the sensor transmission function.
A computer simulation of the depth course of the absorbed dose as a function of the electronic irradiation energy of the acting in the range of 30 – 60 keV was performed, and calculations of the dose accumulation factor under these conditions were performed for polyethylene terephthalate, polymethylmethacrylate, polystyrene and low-density polyethylene, as model polymers of microelectronic device housings. It is shown that the electron energy values corresponding to the maximum dose accumulation factor depend on the polymer density. The conducted studies allow us to determine with great accuracy the conductivity of plastic cases of microelectronic devices under conditions of electronic irradiation, which is of particular interest to exclude the physical possibility of the occurrence of electrostatic discharges that lead to failures of the onboard electronics of spacecraft.
The signal processing method based on extremal filtration in low signal-to-noise ratio conditions was proposed. The extremal filtration is similar to the empirical mode decomposition (EMD) method, but complex mathematical calculations are absent that is the main advantage. Using it in real measuring devices significantly increases the speed rate. The extremal filtration process is an algorithm that involves sequentially repeating until an optimal result. The disadvantage of this method is decreasing the spatial resolution since every iteration due to a reduction in the number of samples. It is an especially negative fact in areas of sharp signal change. This paper demonstrates how to solve this problem using linear interpolation and to improve the result obtained by simple extremal filtration.