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Vol 17, No 11 (2016)
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METHODS OF THE THEORY OF AUTOMATIC CONTROL

723-731 798
Abstract
The article is devoted to approaches to determination of the degree of observability, controllability and identifiability of the parameters in the linear dynamical systems. Well-known criteria for determination of the observability, controllability and identifiability of the dynamical objects were presented. Those criteria only allow us to determine, which component of the state vector is observable or controllable better. They can only give a relative assessment of the quality of the observability and controllability ofa specific component ofthe state vector ofthe system, whereas, it is impossible to compare the quantitative characteristics of the state variables and parameters in various systems. Numerical criteria for calculation of the degree of observability and controllability of the state variables, as well as the degree of identifiability of the model parameters of the dynamical objects were researched using the scalar methods. The proposed numerical criteria have a clear physical meaning, and are characterized by simplicity and versatility. They allow us to determine the quality of the observability, controllability and identifiability in a scalar form, which can be very convenient for practical applications.
732-740 521
Abstract
The authors present the task of control with account of the significant uncertainty of the dynamic structures and non-stationary parameters of objects. Using the analogy between the task and the ways of functioning of the biological systems, one can conclude that it is possible to solve this problem on the basis of the homeostatic control. This technology combines the principles of a multilevel structure of the information control system, its modular structure and the division of each level. This possibility is demonstrated by the example of control of the process of a double-loop counterflow heat exchange, where the primary loop includes an operated heater and the secondary one is intended for a heat supply ofthe external end-users. By the temporal and spatial discretization ofthe process a mathematical model ofthe heat exchange in a different form was developed and imitated in MatLab. It demonstrates that implementation of those principles is advisable in the class of the fuzzy algorithms, which uses a composition ofthe local control in each subsystem. The multi-alternative control system of the process ofthe counterflow heat exchange is synthesized, wherein: we use a controller with five independent channels, which start by the distance of the rated state and ensure the property of homeostasis; an alternative channel of the input disturbance, which operates at a high-speed system, is implemented; an additional control loop of the primary coolant flow, which prevents critical temperature conditions in the heat exchanger is constructed. By a simulation model the quality indicators of the system are checked and the effectiveness of the multi-alternative principles is confirmed. The article ends with a discussion of the concrete practical results, obtained by multilevel processing of information in the system, modular formation of the control solution and variety of processing and separation methods of the subsystem function. Good prospects for use of the multi-alternative concept for the control systems with a fundamental indeterminacy of the structure and the parameters are confirmed.

ROBOTIC SYSTEMS

741-749 497
Abstract
This work is devoted to the topical problem of elaboration of new principles of a decentralized cooperation of the computer systems, which will create a new class of unmanned robotic productions (URP). In the shortest possible time they could produce a variety of prototypes and individual items meeting the remote customers' requirements. Use of the principles of decentralized multiagent scheduling of URP ensures: firstly, high availability of the system, because it lacks the 'bottleneck" in the form of a central controller, and a failure of any of the agents does not lead to the catastrophic consequences for the entire URP; secondly, a possibility of virtually unlimited increase of the number of nodes as a part of URP because of an easy connectivity to the information communication channel; and, finally, thirdly, a reduction of the computational load on an individual software agent in the solution of the scheduling tasks, which in turn, makes it possible to get solutions in real time. This article describes the generic principles of organization and functioning of the unmanned robotic productions with a decentralized controller. Implementation of these principles ensures: - a possibility of automation of the approach to the flow of tasks of production of various products coming from customers in advance and in unknown times; - an adaptive quasi-optimal allocation of resources based on their expertise in the real-time of receipt of the assignments; - a high payload operation of the nodes in the URP; - a possibility of unlimited scalability; - an increased fault tolerance, since it lacks components, the failure of which could lead to a failure of the entire system.
750-761 849
Abstract
The problems of the analysis and passage of the unknown medium by wandering automata over it is the subject of the study of the theoretical computer science. The maze is very popular geometric model of such medium. The mazes as the artificial testing medium for the experimental research of traffic control algorithms of the autonomous mobile robots are widely used in robotics. The paper is dedicated to the problems of maze passage by robotic intelligent agents (IA). The most principle aspects of the algorithmization of mobile robots conduct may be study by means of computer simulation of maze search. The conception of virtual mazes and virtual robots living in them is discussed in the article. It is given the short review of the results of the theoretical researches of the final automata conduct in chess mazes. They permit to understand the possibilities of mazes passage by the reactive agents. The problem of going around of mazes by the IA occupies the central place in the article. The IA in contrast to the reactive agents are capable to analyze the habitat, to design and optimize its own conduct. In connection with it the statement of the maze problems is changed cardinally. The architecture of the IA which are able to decide the wide class of the maze problems is analyzed. The question of the structure of the situating models of IA conduct occupies the central place in the article. The simplest situating model of the agents' conduct is the static one and it is constructed on the basis of the productions "situation-action". But for the planning ofIA conduct it is necessary the dynamic situating model complemented with the event mechanism of the situations control. In this case the cycle of control by the agent conduct has the following stages: the analysis of the situation - the generation of local purpose - the planning of actions - the fulfillment of plan. The formal scheme of the structure of the mathematical models of the situating control processes and the planning of the actions of the IA is proposed. The considerations about the co-ordination of the agents' actions are reduced. The method of the optimization of the routes of the movement in the maze based on the reduction of the initial optimization problems for the checked maze to more simple problem of search of the shortest route of the weigh graphs is suggested.
762-768 489
Abstract
The topic of the article is the problem of the actuator dynamics simulation for the training complexes. Usually, when the mathematical model for a motor is formulated, its passport parameters are used: starting torque, idle speed and electromechanical time constant. The actuator creates the control action, which makes it possible to control the relative motion of the two joining rigid bodies. For the real-time dynamic simulation of the articulated rigid bodies the method of the sequential impulses is proposed. within this method the actuator dynamics is realized by means of a special constraint, which correlates the bodies' coordinates with the engine's angle rotation. In order to model the complex mechanisms, which are controlled by a single motor, a special "repeater" constraint is proposed. This constraint allows us to simulate the movement of the manipulator gripper jaws. The method of the sequential impulses with stabilization on the basis of the split impulses is iterative, while the use of the specific criterions for the end of iteration allows a real-time simulation. jhe proposed algorithms and methods are implemented in the software modules written in C+ +. Their approbation was carried out in a dynamic subsystem for a robot simulator. The studies demonstrated that the proposed methods and algorithms allow us to solve the problems, associated with implementation of different kinds of robots control. Such technologies can also be used in the virtual labs, simulation complexes, systems of augmented virtual environment and other applications.
769-775 354
Abstract
One of the promising directions of robotics is the aggregate-modular method of construction of the industrial robots. The aggregate-modular method of construction of the industrial robots has many advantages. One of the positive factors of the aggregate-modular approach to construction of robots is a possibility to formalize the design process of robots. In this connection, one of the urgent tasks is development of the methods and algorithms for synthesis and analysis of the industrial robots on the basis of the aggregate-modular approach. The basic algorithm for an automated synthesis of the industrial robots is the synthesis of the structure of an industrial robot. The synthesis is performed on the basis of a model range of the standard modules, settings, operations and settings of the working environment, in which the functions of a robot are synthesized. The author proposes a recursive algorithm for a structure synthesis of the robot manipulators for building a robot based on the aggregate-modular approach. The proposed synthesis algorithm allows us to reduce the computing resources procedure required for the synthesis compared with a full search of all the possible variants and selection of the most suitable option of a robot. The results of the synthesis are converted into a format, readable by a dedicated system of simulations. This allows us to evaluate the synthesized version of the robot when performing scheduled operations in the external environment.

CONTROL IN AEROSPACE SYSTEMS

774-782 1100
Abstract
In this article the authors propose a decentralized control algorithm for a swarm consisted of quadcopters, which are unmanned aerial vehicles (UAV) lifted and propelled by four rotors. The first step was derivation of a quadcopter flight dynamic (math) model and its further linearization. The math model was derived on the basis of Newton and Euler equation of motion. The next step was to design a trajectory control algorithm by using PD regulator for the trajectory error minimization. After designing and approbation of the control algorithm of a unit quadcopter, the authors proceeded further with the task of a group control. Originally, the authors set several requirements to the control algorithm of the quadcopter for a group flight, e.g. cohesion and safety of the flights, decentralization and scalability of the control algorithm. As a ground algorithm they selected C. Reynolds rules designed for "boids". In order to make it possible to switch a quadcopter group flight from the swarm mode to the formation mode, in addition to Reynolds rules the authors developed the forth rule called "Formation". Before designing of the decentralized control for a quadcopter swarm, the authors solved similar tasks related to the kinematic control and dynamic control of the agents moving in 2D. The authors set several experiments in a "Universal Mechanism" and "Matlab" of the quadcopter group flight of10 agents with independent control systems. The above-mentioned experiments proved the efficiency of the designed decentralized control algorithm. The modeling details and experiment results are also presented in the paper.
783-791 409
Abstract
Below is a solution for a direct-sales representative in case of a two-dimensional routing of a flight, which differs by formation of two initial matrixes of the distances between the points of two unlinked routes, which are analyzed in turn with a coordinated selection of the element of the minimal length in each of them. In comparison with the known branch and bound method, there is no need in an additional choice for an alternative, which is essentially new in the solved task - to which of the two routes the element should belong to. For this purpose it is necessary to know, to what route it is closer to, and for evaluation of this proximity two criteria are used: - at the first stage of calculation on each step it is the calculation of the minimal distance from an element to the center of gravity of each of the routes by using the triangular model of approximation of the flight trajectory. This allows us to part gradually step by step the centers of gravity at a certain distance, sufficient to continue the calculations; - at the second stage of calculation, the minimal distances from the element to the approximated trajectories of each route are calculated, which allows us to refuse in case of their equality in general accession of the element to any route and by that to avoid an unnecessary inclusion of the crossing points between them. Examples of the calculations proving the efficiency of the offered approach and indicating reduction of the performance of the flight of points more than twice are presented.


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