The Structure of the Exciter of a Dielkometric System for Research of Biological Objects Using an Adaptive Interference Canceller

An important task in the development of sources of electromagnetic vibrations used in the design of dielkometrical systems for biological objects is to reduce the level of interference of the electromagnetic vibrations source in the output spectrum. Methods for suppressing side components in the output spectrum conflict with the dynamic characteristics of the electromagnetic vibrations source, in particular, they do not meet the requirements for the tuning speed in the specified wave ranges. (Research purpose) The research purpose is in developing the basic structure of the exciter of the dielkometric system for the study of biological objects, allowing obtaining previously unacceptable values of suppression of the comparison frequency and its harmonics. (Materials and methods) Authors applied the compensation method to obtain the required spectral and dynamic characteristics of the electromagnetic vibrations source. The article sets the problem of adaptive noise compensation, which was solved using a quasi-optimal method, the method of the minimum of the average square error. (Results and discussion) The article proposes the basic structure of the exciter of the dielkometric system for the study of biological objects. It was shown that the adaptive method results in suppression of side components in the spectrum of the output signal source while maintaining the required speed. The spectral components of the output signal of the electromagnetic source were studied using a functional method. It was found that there is an effective convergence of the transfer functions of adaptive filters of the adaptive compensator of side components to the nonlinear transfer function of the corresponding orders of the dynamic system. (Conclusions) The article presents the developed structure of the exciter of the dielkometrical system using an adaptive compensator of side components, which allows to obtain previously unacceptable values of suppression of the comparison frequency and its harmonics. It was found that the use of this structure of the exciter will improve the dynamic characteristics of the dielkometrical system as a whole. It was found that the use of adaptive filters increases the speed of the exciter by 5-10 times.

Adaptive compensation control of an electromagnetic active suspension system based on nonlinear characteristics of the linear motor

With the electrification and intellectualization of vehicle systems, electromagnetic active suspension has been paid more and more attention. Linear motor is one of the effective actuators of the electromagnetic active suspension system. The nonlinear factors of linear motor, such as nonlinear friction force and ripple force, as well as power limit and magnetic saturation, will reduce the performance of electromagnetic active suspension. However, the current research rarely considers the effect of these nonlinear factors on active suspension control. In this article, the effect of nonlinearities of linear motors on electromagnetic active suspension performance and the ways to improve their performance are studied. An adaptive filtering compensation method is proposed to reduce the influence of nonlinear factors on the electromagnetic active suspension control. According to the simulated calculations, performance degradation of the active suspension is observed in both the primary control objective and high-frequency range due to inherent disturbance from the nonlinear factors. Also, the electromagnetic nonlinearities will reduce the active suspension effective force output. By proposing an adaptive compensator based on the filtered-x recursive least squares algorithm, the first-order resonance of the suspension system could be controlled and the electromagnetic active suspension effective force could be magnified. Also, convergence of the adaptive compensator is found to be rapid and reasonable.

Результаты экспериментальных исследований по обнаружению пловцов при развитой структуре интерференционного гидроакустического поля в прибрежной акватории берегового клина

В статье показано, что прилегающая к особо важным объектам акватория берегового клина, остается не освещенной, и при подсветке высокочастотным сигналом, в ней формируется интерференционное гидроакустическое поле, в котором можно регистрировать движущихся пловцов. Рассматривается механизм возникновения амплитудной модуляции при отражении гидроакустического сигнала от взволнованной морской поверхности. Приведены результаты компьютерного моделирования, а также лабораторных исследований, показывающие принципиальную возможность выделения на приемном устройстве амплитудных флуктуаций, вызванных движением подводного объекта в созданном интерференционном поле. Представлена модель адаптивного компенсатора помех, а также приведены результаты натурных экспериментальных исследований, которые показывают, что предлагаемый компенсатор позволяет подавить помеху, вызванную отражением высокочастотного сигнала от взволнованной поверхности на приемном устройстве и выделить амплитудные флуктуации, вызванные движением пловца. Показана эффективность снижения среднеквадратической ошибки помехи на измерительном приемном устройстве после адаптивного компенсатора, а также предложена схема обнаружителя движущегося подводного объекта.The article shows that the water area of the coastal wedge adjacent to particularly important objects remains unlit, and when illuminated by a high-frequency signal, an interference hydroacoustic field is formed in it, in which moving swimmers can be registered. The mechanism of occurrence of amplitude modulation at reflection of a hydroacoustic signal from the agitated sea surface is considered. The results of computer simulation and laboratory studies are presented, showing the principal possibility of isolation on the receiving device amplitude fluctuations caused by the movement of an underwater object in the created interference field. The model of adaptive interference canceller and the results of field experimental studies, which show that the proposed compensator can suppress interference caused by reflection of high-frequency signal from the rough surface on the receiving device and to allocate the amplitude fluctuations caused by the movement of the swimmer. The efficiency of reducing the RMS error of interference on the measuring receiver after the adaptive compensator is shown, and the scheme of the detector of a moving underwater object is proposed.