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The purpose of the scientific research, results are determinated in the article, is to analytically synthesize the control law of an unmanned aerial vehicle while guiding one along the trajectory that specified by the reference points of space in an inertial coordinate system. The analysis of various existing approaches of the formation of a given flight path of an unmanned aerial vehicle based on various mathematical formulations of the problem is carried out. To achieve the goal, the flight path is considered as separate intervals, where the control optimization problem is solved. The optimization criterion in general form is substantiated and its presentation in the form of a minimized quadratic quality functional is convenient for analytical control synthesis. As components of the functional, the parameters of the deviation of the flight path of the aircraft from the specified points of space are considered, as well as the predicted parameters of the velocity vector and the control normal acceleration. Moreover, at each specified point in space, the direction of the trajectory to the subsequent point is taken into account, that ensures optimal curvature of the trajectory by specified flight speed of the unmanned aerial vehicle. As a result of analytical synthesis, mathematical dependences are obtained to determine control acceleration, which allow us to get a specified optimal control law on board an unmanned aerial vehicle, which ultimately ensures minimum energy consumption. The validity of the proposed theoretical provisions is confirmed by a clear example, where for a simplified mathematical problem statement the optimal laws of change in control acceleration and the trajectory parameters of an unmanned aerial vehicle are calculated by computer simulation.

Рассматривается метод симплексных погружений, адаптированный для решения задач выпуклой оптимизации с большим числом ограничений. Разработаны две модификации, позволяющие ускорять работу метода. Первая из них использует более экономичный способ расчета невязок ограничений, что позволяет существенно сокращать время работы алгоритма в случае большой размерности задачи. Вторая модификация основана на возможности метода определять неактивные ограничения задачи. Представлены результаты вычислительных экспериментов с использованием модифицированных версий метода симплексных погружений при решении тестовых задач квадратичной и выпуклой недифференцируемой оптимизации., A simplex embedding method adapted for solving convex optimization problems with a large amount of constraints is considered. Two modifications of the method are proposed for better performance. First of them uses a more economical approach to the residual computation for constraints, which allows one to significantly reduce the execution time of the algorithm in the case of a large amount of constraints. One of the important peculiarities of the simplex embedding method is its ability to find inactive constraints. This property of the method is used as the basis for its second modification. The numerical results obtained when solving a number of quadratic and convex nondifferentiable optimization problems show the efficiency of the proposed modifications., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 4 2019

We consider a time-delayed quadratic discrete model of population dynamics under the influence of random perturbations. Analysis of stochastic attractors of the model is performed using the methods of direct numerical simulation and the stochastic sensitivity function technique. A deformation of the probability distribution of random states around the stable equilibria and cycles is studied parametrically. The phenomenon of noise-induced transitions in the zone of discrete cycles is demonstrated.

New key parameters, namely b0 = tg0, 0 - angle of throwing, Ra - top curvature radius and 0 - dimensionless speed square on the top of low angular trajectory were suggested in classic problem of integrating nonlinear equations of point mass projectile motion with quadratic air drag. Very precise formulae were obtained in a new way for coordinates x(b), y(b) and fly time t(b), b = tg where is inclination angle. This method is based on Legendre transformation and its precision is automatically improved in wide range of the 0 values and drag force parameters . The precision was monitored by Maple computing product.