Calculation of stable and unstable periodic orbits in a chopper-fed DC drive

It is well known that electric drives demonstrate various nonlinear phenomena.  In particular, a chopper-fed analog DC drive system is characterized by the route to chaotic behavior though period-doubling cascade.  Besides, the considered system demonstrates coexistence of several stable periodic modes within the stability boundaries of the main period-1 orbit.  We discover the evolution of several periodic orbits utilizing the semi-analytical method based on the Filippov theory for the stability analysis of periodic orbits.  We analyze, in particular, stable and unstable period-1, 2, 3 and

On the asymptotic output sensitivity problem for a discrete linear systems with an uncertain initial state

This paper studies a finite-dimensional discrete linear system whose initial state $x_0$ is unknown.  We assume that the system is augmented by two output equations, the first one $z_i$ being representing measurements made on the unknown state of the system and the other $y_i$ being representing the corresponding output.  The purpose of our work is to introduce two control laws, both in closed-loop of measurements $z_i$ and whose goal is to reduce asymptotically the effects of the unknown part of the initial state $x_0$.  The approach that we present consists of both th

Application of frequency stability criterion for analysis of dynamic systems with characteristic polynomials formed in j1/3 basis

This paper considers the stability of dynamical systems described by differential equations with fractional derivatives. In contrast to a number of works, where the differential equation describing the system may have a set of different values ​​of fractional derivatives, and the characteristic polynomial is formed on the basis of the least common multiple for the denominators of these indicators, this article proposes forming such a polynomial in a specific

Study of the processing of small diagnostic creations on a fluid sourcing by spiral survivals

The article considers the features of the drilling process where there is a change in temperature, hole diameter, and displacement relative to the axis and the impact on the tool, when machining holes with high-speed steel drills there is wear of the transverse edge which is completely rounded to create a conical surface. There is a decrease in the negative value of the front corners on the transverse edge of the decrease in axial force, which led to a decrease in the intensity of wear of the transverse edge.

Positivity and stability of descriptor linear systems with interval state matrices

The positivity and asymptotic stability of descriptor linear continuous-time and discrete-time systems with interval state matrices and interval polynomials are investigated. Necessary and sufficient conditions for the positivity of descriptor continuous-time and discrete-time linear systems are established. It is shown that the convex linear combination of polynomials of positive linear systems is also the Hurwitz polynomial. The Kharitonov theorem is extended to the positive descriptor linear systems with interval state matrices.

Ensuring the stability of voltage-to-current converter with complex load

In this paper, the method of determining the stability of the voltage-to-current converter (VCC) with complex load, which is built on the DC amplifier with a deep negative feedback (NFB) by current. The feedback signal is formed on precise resistor, which is connected in series with an inductive load. The deep feedback and complex load can cause a violation of the stability of the VCC across the whole dynamic range of operation.

Investigation of Stability of Parametric Amplifiers in an Environment MAOPCs

The paper considers the question of the research of assessment of the stability of linear periodically time-variable circuits by the frequency symbolic method. The function system MAOPCs, which is based on the frequency symbolic method, is an effective tool of investigation of linear periodically time-variable circuits and in particular parametric amplifiers.

Визначення розрахункової довжини стрижня з пружним закріпленням кінців

The paper proposes the equation of stability compressed bar with elastic supports, which takes into effect of displacement one support to the other. Solution of the equation allows computing a coefficient of reduced length μ of the bar in the frame structure.

Розрахунок стійкості залізобетонних пологих оболонок з урахуванням дефектів при виготовленні

The minimal critical loadings and forms of the stability lost of the symmetric positive gayssian curved models of the shells with local imperfections were determined.