Vol 56, No 3 (2017)

This paper proposes a criterion based on which, using methods of mathematical programming, an algorithm is constructed for successively reducing the limit complexity of a controller.

The optimal stabilization problem is considered for bodies in electromagnetic suspensions. To solve this problem, we form a linear stationary control law for the linearized system. This law is based on the feedback principle and uses the measuring of the current intensity in the circuit of the electromagnet, while the location of the body and its velocity are not measured. The optimality criterion is the generalized H_∞-norm of the linearized system: it characterizes the extinguishing level for perturbations generated by external actions and unknown initial conditions. To compute the feedback parameters, the technique of linear matrix inequalities is applied. We provide mathematical simulation examples for the dynamics of a body in an electromagnetic suspension.

This work considers nonautonomous control systems with uncertain nonlinearities subjected to the impact of external disturbances which are continuous functions bounded by the L₂-norm. Based on the method of matrix comparison systems and technique of differential linear matrix inequalities, it is proposed to solve problems of finite time stability and boundedness with respect to the given sets, as well as suppress the disturbances and initial deviations using the state feedback with an estimation of the performance by the H_∞-criterion.

In 2014, P.S. Krasnoshchekov, Academician at the Russian Academy of Sciences, offered A.A. Belolipetskii to continue research on the collective behavior of people by generalizing his earlier static model to the dynamic case. For this reason, this work is regarded as a tribute to commemorate Krasnoschekov, an outstanding scientist. The fundamental quantitative model Krasnoshchekov proposed in his works studied a static model of collective behavior when people can change their original opinion on a subject after one stage of informational interaction. Opinions are assumed to be alternatives. A person can support his country to join the WTO with probability p and object to it with probability 1 - p. In this work, multistep opinion exchange processes are considered. Quantitative characteristics of values of probabilities p (of people’s opinions) are obtained as functions of the step number and the rate of change of these probabilities. For instance, the way the mass media can control the opinions of their target audience if this audience has certain psychological characteristics is studied.

The redundant equipment system configuration control problem is considered. The proposed method is based on the use of software and hardware, called supervisors, the number of which corresponds to the number of possible configurations. Each supervisor monitors its system configuration with the determination of its readiness index. Then, the preferred configuration is selected and implemented by performance indicators based on arbitration between supervisors with positive readiness indices. An example of redundancy control in a simplified aircraft navigation system is presented.

It is proposed to estimate the energy consumption of logic circuits implementing digital devices using the results of rapid modeling of both the structure descriptions of logic circuits and the original algorithmic descriptions of the devices by which the logic circuits are designed. The energy consumption estimation is reduced to finding power-hungry test suites that cause increased energy consumption. Two methods for the algorithmic description of digital devices are proposed. The algorithmic descriptions are used to design logic circuits that differ in energy consumption, area, and speed. The experiments show that the proper description of the device operation at the algorithmic level helps significantly reduce its energy consumption.

This review is devoted to the control problem with constraints on the magnitude and rate of change of the control action in aircraft control systems. In engineering practice, it is accepted to use actuators with a sufficiently large level of magnitude and energy supply. Theoretical investigations in the field of systems with saturation in the control loop should provide engineers with design methods for the minimization (as much as possible) of the weight–size and energy characteristics of actuators. Therefore, such investigations are highly relevant for practice. The review is focused on a specific effect that can occur when there is an integral component in the control law, the so-called integrator windup, that leads to the deterioration of the quality of system processes, a significant increase in control errors, sometimes to the loss of function associated with the occurrence of large amplitude limit cycles, and even to a loss of stability. The occurrence of this effect in aircraft flights can have dramatic consequences. Thus, the suppression of this effect is an urgent task for designing aircraft control systems. The main part of this review is devoted to the corresponding methods.

We consider the problem of attitude control of a descent vehicle in the Earth’s atmosphere returning from the Moon. A stabilization algorithm with a deadband and the optimal parameters, obtained with the numerical method, provide adequate landing accuracy and an allowable load factor under the influence of a set of disturbances. Using the method of mathematical simulation, it is shown that the fuel consumption is reduced by ~30% in comparison with the initial stabilization parameters for the descent from a near-Earth orbit.

A way to maneuver a high-speed aeroballistic missile (AMB) flying over an area where it can be shot down by enemy air and antimissile weapons is presented. It involves configuring the maneuver and setting reference points’ coordinates in a conditional coordinate system in advance. For setting the trajectory of an ABM with an anti-interception maneuver, the ABM is homed-in step-by-step to each reference point, whose coordinates are transformed in advance into a coordinate system connected with a certain area on the Earth. This offers the advantage of the possibility to plan maneuvers with any configuration without breaking the restrictions set on the controlling parameters.

We construct a programmed motion of the drive to adapt a walking mover to the supporting surface based on the optimality criterion that takes into account the energy costs of movement, the shockless interaction with the ground, and the traction–coupling properties in stepping.