Abstract
Abstract. The stability problem of a system of differential equations with a right-hand side periodic with respect to the phase (angular) coordinates is considered. It is convenient to consider such systems in a cylindrical phase space which allows a more complete qualitative analysis of their solutions. The authors propose to investigate the dynamic properties of solutions of a non-autonomous system with angular coordinates by constructing its topological dynamics in such a space. The corresponding quasi-invariance property of the positive limit set of the system’s bounded solution is derived. The stability problem with respect to part of the variables is investigated basing of the vector Lyapunov function with the comparison principle and also basing on the constructed topological dynamics. Theorem like a quasi-invariance principle is proved on the basis of a vector Lyapunov function for the class of systems under consideration. Two theorems on the asymptotic stability of the zero solution with respect to part of the variables (to be more precise, non-angular coordinates) are proved. The novelty of these theorems lies in the requirement only for the stability of the comparison system, in contrast to the classical results with the condition of the corresponding asymptotic stability property. The results obtained in this paper make it possible to expand the usage of the direct Lyapunov method in solving a number of applied problems.
Highlights
The authors propose to investigate the dynamic properties of solutions of a non-autonomous system with angular coordinates by constructing its topological dynamics in such a space
The stability problem with respect to part of the variables is investigated basing of the vector Lyapunov function with the comparison principle and basing on the constructed topological dynamics
Theorem like a quasi-invariance principle is proved on the basis of a vector Lyapunov function for the class of systems under consideration
Summary
Достаточно широкий класс дифференциальных уравнений, изучаемых при моделировании ряда задач механики, физических процессов, систем автоматического регулирования, составляют уравнения с угловыми координатами. Развитие теоремы Барбашина-Красовского о полной асимптотической устойчивости [3] и принципа инвариантности Ла-Салля [4] на системы с угловыми координатами в автономном случае со скалярной функцией Ляпунова, имеющей знакопостоянную производную, приведено в работах [5,6], а в неавтономном случае с такой же функцией Ляпунова – в работе [7]. Широкое применение соответствующих результатов в решении прикладных задач продолжает стимулировать интенсивные исследования этих направлений теории устойчивости [12,13,14,15,16]. Целью настоящей работы является изучение малоисследованной задачи о частичной устойчивости системы дифференциальных уравнений с угловыми координатами на основе векторной функции Ляпунова. В третьем разделе исследуется применение векторной функции Ляпунова с принципом сравнения для решения исследуемой задачи.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
