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Vol 21, No 2 (2020)
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SYSTEM ANALYSIS, CONTROL AND INFORMATION PROCESSING

67-74 871
Abstract
The design of adaptive controllers allows to solve the problem of control of the object with non-stationary parameters. However, if the parameters of the object do not change too much or if only a certain interval of their change is known, it may turn out that an adaptive controller is not required, since the problem can be solved with the help of a robust controller. The robust controller allows to provide an acceptable quality of control even if the parameters of the mathematical model of the object change in some predetermined interval. A method of designing such controllers is known as the method of numerical optimization of the controllers used in the ensemble of systems in which the models of objects are different and the models of controllers are identical. The ensemble uses object models with extreme parameter values. The disadvantages of this method are too many systems that need to be modeled and optimized at the same time if there are several parameters to be changed. In addition, the worst combination of model parameters may not be boundary, but middle, in this case this method is not applicable. This article offers and analyzes an alternative method of designing a robust controller on a numerical example. The essence of this method is the numerical optimization of the regulator for the model with the worst combination of the values of all modifiable parameters. The search for the worst combination of parameters is also carried out using the method of numerical optimization. In this case, a combination of model parameters is found in which the best relation of regulator coefficients gives the worst result of the system. The problem is solved in several optimization cycles with alternating cost functions. The utility of the method is illustrated numerically by an example of a third order dynamic object with a series linked delay element.
75-85 644
Abstract
Communication networks in space systems involving the use of satellite constellations are DTN networks (Delay and Disruption Tolerant Networks). The establishment of communication channels in space communication networks has certain specifics: communication channels can be planned. In this regard, the CGR approach (Contact Graph Routing) is considered as the most promising solution to the problem of data routing. At the basis of this approach, taking into account this specificity, the calculation of the contact plan is considered. On the basis of this plan in the network nodes contact graphs are calculated, which are used to search the shortest data transmission routes. The paper proposes two interrelated solutions as a modification of this approach: the route search based on the contact plan, i.e. without calculation and use of the contact graph, and an adaptive method of finding the set of shortest routes required for routing. The essence of the first solution is as follows. In the standard CGR approach, the graph vertices correspond to the planned contacts between the network nodes, and the edges correspond to the data storage processes in the network nodes. In contrast, in the proposed approach, the vertices of the graph correspond to the nodes of the network, and the edges of the graph and their weight are determined dynamically, in the process of finding the shortest routes. The second solution is based on the concept of the planning front, which means a list of the closest contacts in time. The required routes are divided into a certain number of pools. Each pool combines the routes that use the specified contact from the planning front. The planning front is updated in two cases. If the network topology changes, the completed or not established contacts are replaced by subsequent ones with the same network nodes that are closest in time. If message traffic grows, a certain extension of the planning front and the use of additional route pools are performed. The article concludes with a description and justification of the expected advantages of the proposed approach.
86-92 507
Abstract
The general principles of automatic control of aircraft engines and functionally related systems in the conditions of their stand tests are suggested. These principles are prospectively reduced to six sequentially implemented procedures or steps. In accordance with these principles, the control of aircraft engine parameters is carried out by a computer-aided test equipment (CTE) based on a computer complex that implements algorithms based on Boolean algebra and the algebra of events and states. These algorithms allow control procedures to be carried out in dynamic mode in accordance with the schedule of testing an aircraft engine. With this control, the specified sequence of operating modes of the aircraft engine undergoing testing is observed without fixing them in time and with the possibility of skipping or repeating individual modes. Parameters are monitored at each of the next aircraft engine operating modes only after all parameters are checked in the previous mode and the value of the main determining parameter reaches the value determined for this mode. During the period of transient processes, parameters are controlled only at the points of extremum of the values of the main determining parameter with fixing the time of transient processes and determining that. "In the tolerance" or "not in the tolerance" is the checked parameter and the fixed time interval. Upon arrival of the signals from the monitoring object, the time of occurrence of which is unknown, and only the time interval during which they can appear is known, any of the CTE operation modes are terminated, tolerance control of the parameters provided by the program is performed, and the previously interrupted mode is restored. Simultaneously with the tolerance control of the parameters, the time of arrival of the above signals is recorded. The group of emergency parameters is monitored continuously throughout the entire period of stand test.
93-101 584
Abstract
The article deals with the issues related to the possibility and limitations of technological creation of artificial systems endowed with consciousness and acting subject existing in the world of artificial subjective reality. The problems of creating an artificial personality in the given parameters are shown. The main obstacle to the creation of intelligent systems is the lack of progress in our understanding of the nature and mechanisms of the brain in the process of generating mental image and organization of purposeful activities. The transfer of psychology data to the engineering sphere is ineffective due to the difference in conceptual and instrumental areas of these disciplines. The approaches of synthetic psychology and pedagogy designed to provide a solution to the problem of creating an artificial subjective reality and techno-genic modification of man are presented.

AUTOMATION AND CONTROL INDUSTRIAL PROCESS

102-109 3905
Abstract
The article is devoted to the analysis of actual problems of automation of control of the installations of electric centrifugal pumps (ESPs) of oil producing wells and modern approaches to their solution. The solution of the problem requires the creation of complex multi-level systems for the adoption and implementation of control decisions. The top (planning) level of control requires the development of decision support systems that perform real-time collection and analysis of large amounts of information about the various work processes with ESPs. Actual tasks of this level are the development of models for identification and forecasting of oil production processes, as well as algorithms for finding control solutions aimed at optimizing these processes. Lower (operational) levels of management require the development of emergency and regulatory control systems that implement decisions taken at the upper levels. The actual tasks of this level of management are the development of dynamic models of the ESP process that provide the synthesis of optimal algorithms for implementing top-level management solutions, such as stabilization, I/O, emergency control. The main goals, tasks of these systems and approaches to the solution are considered. The analysis of ESP as a complex multiply connected control object is given. Controllable parameters, parameters of controlling and disturbing influences are distinguished. The generalized multilevel structure of the ESP control system and approaches to the construction of subsystems solving management tasks at various levels are considered. The approach to the construction of the system of the upper — planning level of the ESP control, the principles of its interaction with higher and subordinate systems is considered. The approach to the construction of the subsystem of the lower — operational level of the ESP control is considered. The tasks of this level of control are considered, including such as emergency control, regulation of the mode parameters, output to the operating mode. The classification of groups of emergency control tasks on protection from the most significant types of negative factors and approaches to their solution is given. The approach to the solution of the problem of ensuring the maximum oil production, as a problem of stabilizing the critical pressure at the pump inlet, is considered. Continuous and positional variants of algorithms for solving this problem are presented.

ROBOT, MECHATRONICS AND ROBOTIC SYSTEMS

110-116 657
Abstract

In this paper a simulation model of cutting speed stabilization for numerical control machines was developed. The mode of cutting speed stabilization allows solving a number of technological problems, including the increase in machining productivity and the quality of the part surface, the increase in durability of the cutting tool.

Access to the functions of the basic software of CNC systems is limited. Taking this into account, this paper considers the functional and algorithmic features of the power parameter stabilization systems, as the basis for the further development of intelligent algorithmic support and software. The existing guidance on cutting conditions is based on empirical dependencies, the use of which for direct application in algorithms for the cutting process automatic control is difficult, since these dependencies determine the predicted, not the current, parameters. The non-stationary model was adopted as the basic structure of the process of shaping parts, the main non-stationary model parameters are determined by the three-dimensional kinematics of the universal machine. The generalized approach to the power parameter systems and the synthesis of the regulators of their main circuits made it possible to identify the simplest version of the structures based on the use of the regulators with parametric feedback. The functional model contains the main components of the CNC system: an interpolator, servo drives of feeds and main motion, as well as additional cycle and analysis modules. The high-speed processing of end surfaces and the conditions for the implementation of cyclic control tasks are considered. The simulation results confirming the performance of functional algorithms and the possibility of their use in intelligent CNC systems are presented.

DYNAMICS, BALLISTICS AND CONTROL OF AIRCRAFT

117-128 595
Abstract
The process of deployment elements of constructions and adjustment of the radio-reflecting network of large-sized transformable space-based reflector is considered. The reflector consists of a frontal network, which is stretched on the power frame, cables, with which the front network is pulled to the rear network to set the desired shape of the reflecting surface. The problem of setting and determining the shape of the radio-reflective network is solved both in one plane and in three planes. In general, the task of adjusting the form of a radio reflecting reticle is solved by affecting the design of the actuators — the element of the control system. For the correct functioning of the reflector in orbit, it is necessary to control the shape of the reflecting surface by stretching the frontal network. For the formation and maintenance of the shape of the reflector, the frontal and rear networks are connecte d by cable-stayed reinforcements (tie rods). The cable connect the opposite network nodes. The cable system is the basis for building a sub-system. Miniature mechatronic modules can be located on each of the adju stable guys. To adjust the shape in one plane, the technique of flexible threads is applied. The possibility of changing the surface by simultaneous action of one or more actuators is sho wn. To adjust the shape in space, the membrane method described by the Laplace equation is used. The piezo actuator, DC motor and servomotor are considered as actuators for setting t he shape. As a mathematical model of the piezoactuator, the model of A. A. Nikolsky is considered. The system is solved taking into account rigid fixation of the reflector response. A comparison of the use of PID-controller and optimal controller. The structure of optimal control is revealed from the maximum principle. The arising two-point boundary value problem is solved by the methods of the steepest descent and Newton. It is shown that the use of optimal control can reduce the time of the transition process. A similar problem was solved for DC motor and servo motor. The advantage of using optim al control methods is shown for all actuators. The solution of the problem with the help of algorithm with correction of parameters of control structure is offered.


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ISSN 1684-6427 (Print)
ISSN 2619-1253 (Online)