0000000000400595

AUTHOR

S. M. Seledzhi

Hidden oscillations in SPICE simulation of two-phase Costas loop with non-linear VCO

Simulation is widely used for analysis of Costas loop based circuits. However it may be a non-trivial task, because incorrect choice of integration parameters may lead to qualitatively wrong conclusions. In this work the importance of choosing appropriate parameters and simulation model is discussed. It is shown that hidden oscillations may not be found by simulation in SPICE, however it can be predicted by analytical methods. peerReviewed

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Hidden oscillations in stabilization system of flexible launcher with saturating actuators

Abstract In the paper the attitude stabilization system of the unstable flexible launcher with saturating input is considered. It is demonstrated that due to actuator saturation the system performance can significantly degrade. The analytical-numerical method is applied to demonstrate possibility of hidden oscillations and localize their attractor.

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Hidden oscillations in nonlinear control systems

Abstract The method of harmonic linearization, numerical methods, and the applied bifurcation theory together discover new opportunities for analysis of hidden oscillations of control systems. In the present paper new analytical-numerical algorithm for hidden oscillation localization is discussed. Counterexamples construction to Aizerman's conjecture and Kalman's conjecture on absolute stability of control systems are considered.

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UAV control with switched GNSS-Estimator navigation system∗∗This work was supported by Russian Scientific Foundation (project 14-21-00041) and Saint-Petersburg State University.

Abstract In the paper the switched GNSS-Estimator navigation system, recently proposed by the authors, is described and numerically studied in the framework of evaluation of the overall UAV control system accuracy.

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Nonlinear analysis of phase-locked loop

Abstract New method for the rigorous mathematical nonlinear analysis of PLL systems is suggested. This method allows to calculate the characteristics of phase detectors and carry out a rigorous mathematical analysis of transient process and stability of the system.

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Combining Academic Education With Soft Skills Development: Some Common Aspects of Educational Preparation of IT Professionals and Schoolteachers

In the modern educational process aimed on preparing professionals in the applied areas, it’s crucial, along with purely professional training, to provide students both with solid theoretical background and help them to develop “soft skills” that will facilitate their smooth and efficient adaptation to the industry realities when they start their professional careers. In this paper we consider practical cases of acquiring soft skills through intensive field experience in two areas related to mathematical education.

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