SYSTEM ANALYSIS, CONTROL AND INFORMATION PROCESSING
The article discusses using discrete-event models to control the coordinated behavior of groups of agents and proposes a mechanism for organizing behavior control based on a hierarchy of finite state machines (FSM). The basic level of agent movement control uses a continuous model of joint movement — the method of potentials, in which the direction of movement is determined by the total sum of the forces of "repulsion", "attraction" and "course alignment". The paper describes a set of independent rules for the group movement of agents — cohesion, distribution, leader following, movement along a chain of landmarks, pursuit, etc. Moreover, all of them are interpreted in terms of the results of the operation of FSM models. Mathematical modeling of controlling a group of agents was carried out using the independent rules of group movement, which confirmed their efficacy. Computational experiments were also carried out using the Gazebo 3D simulator. In addition, the paper describes an experimental group of three underwater vehicles that were used to test the independent rules of group movement: cohesion, distribution, leader following. Communication between the devices was carried out using a system of infrared transceivers via a pseudo-analog channel. The experiments were carried out in a laboratory pool and were successful.
The paper shows that the technology for creating group control systems based on the hierarchy of FSM (meta-FSM) allows solving control problems not only at the level of abstract models and simulation modeling, but also at the level of creating real robotic complexes.
AUTOMATION AND CONTROL TECHNOLOGICAL PROCESSES
The level control of the precarbonised solution in a soda ash production plant requires intelligent approaches that can tackle process complexity, nonlinearity and industrial environment impact. Therefore, model-free fuzzy logic controllers (FLC) with empirical tuning are suggested which are implemented in a general purpose programmable logic controller (PLC) and operate in real time control. Online adaptation improves the FLC parameters tuning. The aim of the present research is to optimise the adaptation strategy and the parameters of an adaptive PLC PID FLC using genetic algorithms (GA) and simulations for reducing both the system error and the control variance. The PID FLC is based on a PD FLC and a parallel integrator of the system error. A Sugeno model is used for adaptation of the PID FLC tuning parameters. Depending on the level it defines empirically via its input membership functions three linearisation zones and performs soft blending of the local for each zone PD FLC gains and integrator time-constants. Two adaptation strategies are suggested for online auto-tuning of the integrator time-constant only, and together with the PD FLC gain. The local parameters, in turn, are GA optimised. Simulations show that the best system performance is achieved by auto-tuning both PID FLC parameters with optimised local values.
Modern capabilities of intelligent control systems are increasingly being used in areas previously considered the exclusive work of people — experts with relevant experience in a particular field. Machine learning capabilities in the field of electric power industry, obtaining forecasts based on the data of intelligent sensors of various purposes are not an exception. At present the Russian Government has adopted a program for the development of the manufacturing industry until the end of 2035: during this time manufacturing output should grow by 192 %. It is obvious that this program should also meet the requirements of the modern scientific concept of industrial revolution "Industry 4.0", when manufacturing enterprises and corporations begin to develop and apply subsystems and elements of "smart manufacturing", which help to build intelligent communications between individual tasks and operations during the entire life cycle of production, in accordance with the principles and methods of systems engineering. It is important to note that the issues of intelligent management in the subject-oriented area of electric power industry (in our case — energy saving), as the basis of any industrial production in modern conditions, require the development and implementation, first of all, of new solutions based on modern IT-technologies. It is known that energy intensity in Russia, according to the World Bank, is 3-4 times lower than in European countries. It is also known that in connection with the new provisions in the field of housing and communal services, aimed at improving economic efficiency in terms of electricity consumption, it becomes very important to ensure its accurate and operational accounting with the possibility of further forecasting of electricity consumption and the state of power grid facilities, which will allow specialized organizations and services, as well as the managing bodies in the shortest time to make a balanced specialized decisions This paper proposes the concept of intelligent control system to manage the process of condition monitoring based on data from intelligent sensors. The novelty of the concept is to consider a variant of solving the problem of integration of information systems associated with weakly structured subject-oriented information flows in the electric power industry enterprise by using methods of set theory and category theory.
In the article, an automatic system for radiation power control of lasers excited by а nonself-sustained glow discharge is studied using industrial lasers of the Lantan series as an example. They are designed for cutting, welding and surface modification of various materials as part of laser machines. The power of laser radiation is one of the most important parameters of a laser that determines its technological capabilities. The radiation power is controlled by changing the ionization pulses frequency of high voltage pulses with duration of 100 ns, given with a frequency of 1-5 kHz. The step response of the laser is experimentally obtained. Laser radiation is fed to a thermoelectric mirror-detector with thermo-EMF anisotropy, which measures its power. After preliminary amplification, the differential signal from the mirror-detector is recorded by a digital oscilloscope. A delay in the change in the laser radiation power relative to the control signal was established. The delay is 1487 ms that is explained by the fact that several ionization pulses are required for the initial exciting of the gas volume before the start of radiation generation. The initial section of the step response and damped oscillations are explained by the presence of a protective choke in the main discharge source connection circuit. The choke slows down the rise in current during the short circuit of discharge, allowing circuit breakers to turn off the power supply. To simulate the transient process, the step response of the oscillating circuit is used. The original signal was filtered to remove noise that does not al[1]low determining the parameters of the step response. To determine the spectrum of the step response, fast Fourier transform is carried out, frequencies introducing noise were cut out, and the inverse fast Fourier transform is performed. According to the step response obtained after filtering, the parameters of the modeling step response are determined. Based on the parameters of the step response, the laser transfer function is calculated. It makes possible to proceed to the calculation of the optimal radiation power controller, which ensures the best quality of the transient process.
ROBOT, MECHATRONICS AND ROBOTIC SYSTEMS
Regular visual inspection of the underwater surface of the ship’s hull to check its integrity and the degree of biofouling is necessary to ensure the safety and efficient operation of the ship. The article proposes a method for the automated solution of this problem using an autonomous uninhabited underwater vehicle (AUV) equipped with a stereo camera controlled by a tilt actuator. The movement of the AUV is carried out along equidistant lines along the ship’s hull with simultaneous video filming of the hull surface. The AUV trajectory is calculated using the visual navigation method (visual odometry). Estimated data on the localization of the AUV relative to the ship’s hull are used in the method of controlling the movement of the vehicle to ensure the stable movement of the vehicle at a given distance from the inspected surface. Direct calculation of AUV localization data is done using the proposed original algorithm, which is implemented in the form of a software tool "stereo rangefinder". The operation of the "stereo rangefinder" is based on the matching of features in images using the SURF detector, followed by the construction of a 3D point cloud. The technique for performing automatic inspection of the ship as a whole is described. Fixed stereo images are also used to build a 3D model of the surface being examined. The applied method of constructing a global spatial model of the surface is based on the union of 3D point clouds obtained for local views. The construction of a 3D point cloud for a particular view is based on a matching of 2D point features on images of a stereo pair (SURF detector / correlation calculation), followed by the use of the ray triangulation method to obtain the spatial coordinates of the points. The presence of a 3D model makes it possible to conduct a detailed visual analysis of the state of the ship’s hull. Simulation modeling of the functioning of the developed tools on virtual scenes was carried out. Quantitative and qualitative performance evaluations obtained as a result of testing showed the acceptability of the proposed method for automatic inspection of the underwater part of the ship’s hull.
DYNAMICS, BALLISTICS AND CONTROL OF AIRCRAFT
Nowadays there are many non-functioning spacecraft in orbit that have run out of fuel, or have failed due to breakdown. Therefore, the concept of a serviced space and the development of space manipulation robot for extending the spacecraft service life are becoming expedient. Space manipulation robot will be able to perform a variety of tasks, from inspecting malfunctions of a serviced spacecraft, to performing repairs and refueling the target vehicle. The article proposes a strategy and algorithms for the guidance and motion control of a space manipulation robot at the stage of rendezvous with a non-cooperative spacecraft to perform maintenance tasks. The purpose of the article is to synthesize the control of the translational and rotational motion of the space manipulation robot for its convergence with the target satellite at a given distance. The control system is presented in the form of a hierarchical two-level "guidance-stabilization" system. At the guidance level, a transition quaternion of the associated coordinate system to the required position is formed, as well as thrust engine control, which ensures the translational motion of the space manipulation robot at the required velocity. At the stabilization level, a control is formed that superpose the associated coordinate system of the space manipulation robot with the direction to the served satellite. The article proposes a scheme and a mathematical model of the propulsion system, angular and translational motion of the service satellite. The modeling of the developed guidance and motion control algorithms in the SIMULINK environment has been carried out.
ISSN 2619-1253 (Online)