ДЕЦЕНТРАЛИЗОВАННОЕ УПРАВЛЕНИЕ В ЛИНЕЙНО-КВАДРАТИЧНОЙ ЗАДАЧЕ ПРИ НАЛИЧИИ ЗАПАЗДЫВАНИЯ В ИНФОРМАЦИОННОМ КАНАЛЕ

This article deals with a linear-quadratic optimal control problem for a group of dynamically coupled systems. It is assumed that each system has its own local controller, and a delay is present in the communication network. A distributed feedback control, which is linear in current and delayed states, is constructed and a sub-optimality estimate for the distributed control is obtained.Исследуется задача минимизации квадратичного функционала на траекториях группы линейных взаимосвязанных систем. Рассматривается случай, когда каждая система имеет свой локальный регулятор, и в несовершенном канале связи между ними присутствует запаздывание. Построена децентрализованная обратная связь, линейная по текущему состоянию и запаздывающей информации. Получены оценки субоптимальности децентрализованных управлений в рассматриваемой задаче

On Necessary and Sufficient Conditions for Near-Optimal Singular Stochastic Controls

This paper is concerned with necessary and sufficient conditions for near-optimal singular stochastic controls for systems driven by a nonlinear stochastic differential equations (SDEs in short). The proof of our result is based on Ekeland's variational principle and some delicate estimates of the state and adjoint processes. This result is a generalization of Zhou's stochastic maximum principle for near-optimality to singular control problem.Comment: 19 pages, submitted to journa

Optimal laser heating of plasmas with constant density

The laser heating of a plasma with constant density is analyzed using optimal control theory. Heating strategies that minimize the total energy spent, the heating time, or a linear combination of the two, for several values of weighting coefficients, are obtained by determining the optimal laser intensity associated with each point of the phase plane. A numerical example is used to illustrate the application of the theory. In this particular example, savings in the energy spent up to 75%, compared with the energy required using a constant laser pulse, are obtained when minimum energy trajectories are implemented. Strategies that minimize the heating time, however, did not yield a significant reduction in the heating time. Numerical results may depend strongly on the initial state of the system as well as on the final ion temperature of the plasma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45228/1/10957_2004_Article_BF00938468.pd

Second-order necessary conditions in optimal control: Accessory-problem results without normality conditions

An optimal control problem, which includes restrictions on the controls and equality/inequality constraints on the terminal states, is formulated. Second-order necessary conditions of the accessory-problem type are obtained in the absence of normality conditions. It is shown that the necessary conditions generalize and simplify prior results due to Hestenes (Ref. 5) and Warga (Refs. 6 and 7).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45219/1/10957_2004_Article_BF00934437.pd