INCREASING THE ACCURACY OF ELECTROSTATIC FIELD STRENGTH MEASUREMENT BY USING AN IMPROVED DIFFERENTIAL TRANSIMPEDANCE AMPLIFIER CIRCUIT (р. 6–14)

An electrostatic field mill (EFM) is widely used to measure the strength of electrostatic fields, the main drawback of which is the occurrence of large measurement errors (up to 15 % in the range from 0 to 1 kV/m). This paper examines the aspects of using transimpedance amplifiers (TIAs) for the tasks of converting the current received from the EFM sensor into voltage, which will make it possible to reduce the instrumental error and ensure the linea rity of the atmospheric electrostatic field strength measurement. In the general case, for the functional circuits of the electrostatic field mill, which include a differential transimpe-dance amplifier, there is the use of two TIA circuits, which are connected in parallel. Despite the simplicity of implementation, such a configuration contains a number of disadvantages and is not optimal. In the paper, a comparative analysis of a typical circuit of a differential TIA and a circuit of an ungrounded differential transimpedance amplifier with zero voltage drop proposed by the authors is carried out

The problem of the reliability of measurements of rotational parameters of electric motors was solved, which was focused on the development of an algorithm for evaluating measurements under conditions of additional noise.An analysis of methodological approaches and mathematical tools used to process and interpret the uncertainty of measurement results was carried out.Cases where they may not be effective due to high noise levels were considered.To detect anomalies in the signal, an algorithm for assessing the reliability of measurements using fuzzy logic was proposed.A structural diagram of the model for measuring the torque of an electric motor under the conditions of a noisy signal was developed, where transfer functions were used to model the angular velocity and torque parameters.A method for detecting anomalies in noisy signals is presented, which identifies the amplitude and time characteristics of spiking pulses.The method includes the application of a wide range of analytical tools for deep analysis of signals and is particularly effective for detecting anomalies that may be hidden in background noise.A prototype of a measuring bench was developed, which uses neural networks to detect anomalies when measuring the rotational parameters of electric motors, which made it possible to obtain a training sample using a sample electric motor and apply it to evaluate the parameters of another electric motor.In a practical aspect, the developed methods and technological solutions for improving the reliability of measurements of rotational parameters of electric motors could be used to make corrections in existing systems.In particular, they could be used in industry, electric transport, as well as in the aerospace and military sectors where the reliability of measuring systems is important.
Keywords: assessment procedure, torque, electric motor parameters, neural network, fuzzy logic.The research focused on two-mass electromechanical systems widely utilized in industry.The challenge addressed in this work was to improve the synthesis of controllers for such systems to simplify it and enhance the quality of transition processes.Traditionally, the synthesis of control system loops for these systems was carried out using integer controllers and standard forms.However, this approach led to the synthesis of complex integer controllers that are difficult to implement.To overcome this issue, an original approach to the synthesis of control system loops based on the fractional characteristic polynomial is proposed.The fractional characteristic polynomial ensures the desired quality of the transition process given the implementation of a specified structure of the fractional controller.A new method of structural-parametric synthesis of fractional-order controllers is developed for the case of their cascade connection in multiloop two-mass electromechanical systems.Additionally, an algorithm for synthesizing fractional-order controllers for the corresponding control loops is presented.This enabled the structural-parametric synthesis of fractional-order controllers for a two-mass electromechanical system with the cascade connection of controllers.Such an approach provides better quality of transition processes compared to classical integer controllers, simplifies the synthesis, and thereby enhances the quality of the synthesized systems.The impact of the synthesized fractional-order controllers using the proposed approach on the dynamic properties of the two-mass «thyristor converter -motor» system was investigated.The research results demonstrated the practical applicability of fractional controllers designed using the proposed method for the synthesis of automatic control systems of two-mass electromechanical systems in the industry.

Dmytro Tsibulnikov
Kharkiv National University of Radio Electronics, Kharkiv, Ukraine ORCID: https://orcid.org/0000-0001-5658-6862 The object of this study is the process of detection and tracking of air targets.
The task being solved is to choose priorities between hardware and software solutions to eliminate structural contradictions in the design of a supporting and rotating device, which at the same time should ensure high speed and accuracy of tracking aerial objects for the optical-electronic station.
A prototype of an optical-electronic station was designed and built.The study of the effect of eliminating structural contradictions by hardware and software methods on the accuracy characteristics of the supporting and rotating device was carried out.We have developed original specialized software for testing the accuracy of command execution.
A procedure for testing the optical-electronic station has been devised.All conducted tests were performed in compliance with accepted norms and standards.
The mechanism of influence of the method of controlling the servo drives of the supporting and rotating device on the characteristics of the optical-electronic station has been established.In this case, the program method has priority.In contrast to existing solutions, the developed software method of controlling the support-turning device makes it possible to exclude stops at the limits of the servo control period and to realize a smooth transition to a new value of the tracking speed.Owing to the improvement of forecasting and synchronization of servo parameters with the period of its control, it was possible to solve the investigated problem by the software method.
The mechanism of influence of the inertia of the supporting and rotating device on the characteristics of the optical-electronic station has been established.In this case, the hardware method has priority.
The results could be used to improve the characteristics of optical-electronic stations in the detection and high-precision tracking of moving objects in the air environment.
Keywords: optical-electronic station, supporting and rotating device, control of servo drives, software method.The theoretical possibilities of increasing the resolution and sensitivity of a time-of-flight mass spectrometer with orthogonal ion injection are considered.The effects are achieved by using inhomogeneous electrostatic fields of special configurations both in the accelerating and focusing parts of the device -a cylindrical immersion objective and a transaxial mirror, respectively.It is shown that the use of an inhomogeneous cylindrical field of a special configuration as an ion accelerator opens up the possibility of a multiple reduction in the energy spread of ions in injected ion packets, associated with the so-called «turnaround time» and, there-fore, a significant (two or more times) increase in the limiting resolution of the mass spectrometer.The use of a transaxial electrostatic mirror as a time-of-flight mass analyzer makes it possible to significantly increase the sensitivity of the mass-spectrometer due to the implementation of triple spacetime-of-flight focusing of ion packets.Key features include reduced ion energy spread, increased maximum resolution, and improved sensitivity due to triple focusing in space and time of flight.This research lays the foundation for expanding the capabilities of time-of-flight mass spectrometry, providing a more efficient and powerful tool for a wide range of scientific and industrial applications.The effects are achieved by using inhomogeneous electrostatic fields of a special configuration in both the accelerating and focusing parts of the device -a cylindrical immersion lens and a transaxial mirror, respectively.Numerical calculations of the systema four-electrode cylindrical immersion lens in combination with a three-electrode transaxial mirror -are presented, which confirm the conclusions of the theory.