Vol 58, No 6 (2019)

In this paper, we study the process of controlling the rotation of an object relative to a rotating base using a two-stage electric drive that represents two gearless direct-current motors connected in series. The stator of one of the electric motor is rigidly fixed to the base while an object is fixed to the rotor of the other motor. Between the rotor and the stator of the second motor, there is a torsion spring (torsion) with a relatively low level of stiffness. The aim of the control is tracking by an object a specified orientation relative to the base. The drive control algorithm is built taking into account the incompleteness of the information on the dynamic parameters of the mechanical system, friction acting in it, laws of motion of the base, and changes in the tracked orientation.

Based on the multistructuredness and clustering principles, as well as the filtration theory, we develop a new estimation method for the motion parameters of a radiating target under the assumption of a fundamental indefiniteness of the operating conditions for the triangulation measurement system. The method admits anomalous measurement errors in the measurement channels (the azimuth and the angle of elevation) of particular system locators such that neither the number of uncertain channels neither the time moments of the appearance of these errors are known (only the greatest possible number of uncertain channels is known). The method is implemented in the stochastic variant with or without the participation of an operator. The implementation does not require the traditional extension of the space of states. We provide the results of the comparative analysis demonstrating the efficiency of the method.

The method of sequential modification of an objective function, which was earlier used for the classical transportation problem, is extended to the case of three indices. In the iterative process, the problem with three constraints and one binding variable is solved. Then, three independent problems with one constraint in which the coefficients for the binding variable are changed are considered. Using the suggested algorithm, a sequence of pseudosolutions with a monotonic growth of the objective function that converges to the optimum is constructed. The degeneracies are analyzed.

Within the formalism of the mathematical model of transferring a multicommodity flow, the reachability set of multiuser network systems is studied. A method is proposed for constructing an internal supporting frame based on the vectors of the maximum flows that can be transferred between all pairs of nodes in exclusive and limited exclusive modes of flow control. Using the obtained limit values, we construct a polyhedron of a simpler structure (frame) belonging to the set of reachable multi-flows and a cone of possible directions for the generation of boundary points. Methods for obtaining various multicriteria evaluations of the functional capabilities of a transmission network are considered. The developed approach can be used for the a priori analysis of the set of reachable multiflows, including quickly obtaining estimates and acceptable options for the fair distribution of the limited capacity of the transmission network.

We consider basic approaches to decision-making using computer systems. Ambiguous results in decision-making are obtained through the use of different methods for source-data processing. In order to obtain a single result from an aggregate of such decisions, it is suggested to apply the principle of selecting the decision that is most proposed by John von Neumann to increase the reliability of computers. Based on multiset theory, we develop a mathematical model of selecting a single result from an aggregate of alternatives obtained using different methods of decision-making. In this model, a decision is selected based on computing the argument of maximizing the multiplicity functions of elements for the arithmetic sum of multisets of the obtained decisions. The peculiarities of applying this approach are considered and methods of adjusting the source data for obtaining a single result are proposed. By the example of selecting a metal for electroplating products we present the results (of the decisions taken) obtained by a group of experts using the described approach. Recommendations for improving the efficiency of the proposed approach are presented.

When developing the intelligence support systems designed for the crew of anthropocentric objects that recommend a method of solving the arising tactical-level problem for the crew (real-time targeting + construction of a method for attaining a real-time assigned target of functioning), it is extremely important to adequately understand the subject domain of the database of such systems. One way to accomplish this is to use dynamic fragments of problematic subsituations in a knowledge database with intelligence agents incorporated into them. The general structure of intelligence agents used in the knowledge databases of onboard teal-time advisory expert systems for the typical situations of the functioning of anthropocentric objects is given from the viewpoint of the “Stage” conceptual model of an anthropocentric object. Certain intelligence agents and their use in the knowledge database of a certain onboard real-time advisory expert system for the typical situation of the functioning of anthropocentric objects are considered as an example.

An analytical solution of the problem of estimating the coordinates of the axis of a cylindrical surface and its radius by processing range images is obtained. The proposed methods and algorithms can detect fragments of such surfaces in range images with the prescribed confidence probability. The method is also generalized for finding spherical surfaces in range images. The efficiency of the proposed methods and algorithms is verified by simulation using real-life range images of urban industrial scenes.

The problem of joint synthesis of a modal controller and observer is solved analytically for a sixth-order system that describes the rotational motion of a spacecraft with the available measurements of five components of the state vector. The modeling results that describe the application of the synthesized control and observation laws for the construction of the orbital orientation of a spacecraft are presented in the paper.

We consider the motion of an artificial satellite of the Earth of the Progress and Foton-M4 type in different variants of the orbital orientation mode in low Earth orbit. A gyro system (a set of reaction wheels or control moment gyros) is used as the executive part of the satellite control system. The gravitational and restoring aerodynamic torques acting on the satellite are taken into account. Based on the principles of the proportional-differential regulator, we construct the control laws for the gyrostatic momentum, which allow, without its accumulation, maintaining a long and sufficiently accurate orientation of the satellite in the vicinity of gravitationally stable and unstable rest positions that exist in the simplified problem (the satellite moves in a fixed circular orbit under the action of the gravitational torque only; the gyrostatic momentum is zero).

It is shown that if a robot’s body has an upper shell in the shape of a truncated cylinder, then a six-legged insectomorphic robot can autonomously bring itself to a normal position from an abnormal upside down position using a cyclic leg motion. A method for rocking the robot that helps it to turn itself over to the normal position is proposed. An analytical analysis and computer simulation of the complete robot dynamics are performed, which confirm the effectiveness of the proposed method of recovering the normal position of the robot. The results of numerical experiments are presented.