Discrete Stochastic Regulator on a Manifold, Minimizing Dispersion of the Output Macrovariable

2019 ◽  
Vol 20 (12) ◽  
pp. 707-713 ◽  
Author(s):  
A. A. Kolesnikov ◽  
S. I. Kolesnikovа ◽  
S. A. Tsvetnitskaya
Keyword(s):  
Control System ◽  
Classical Method ◽  
Control Strategies ◽  
Stochastic Matrix ◽  
Center Of Mass ◽  
Target Manifold ◽  
Third Stage ◽  
Initial Control ◽  
Variable Dispersion ◽  
Linear Object

A theoretical result is presented in the form of a new algorithm for the synthesis of a control system over a non-linear object, whose mathematical model represents a stochastic matrix difference equation having noise with a zero mean and finite dispersion in the righthand part. The new algorithm for synthesizing stochastic control for such an object is based on a three-stage procedure. In the first stage, the structure of the control system is formed in accordance with the classical method of analytical design of aggregated regulators (ADAR) in a fixed-noise assumption. In the second stage, the conditional mathematical expectation of the resulting expression for the first-stage control is determined. In the third stage, the control model is refined by excluding the noise variable from the control formula based on decomposing the initial control system affected by the new control. It is shown that the proposed control strategies minimize the target macro variable dispersion and ensure a stable, on average, achievement of the target manifold. A detailed example of an application of the algorithm for synthesizing control over the motion of an immobile center of mass is given, whose analog is represented by the objects such as by robot-manipulators, is given. The results of numerical modeling are presented, which confirm the operability of the constructed controller. Numerical simulations of the designed control system was performed using the authentic working equipment data.

scholarly journals Satellite Attitude Control System Design Taking into Account the Fuel Slosh and Flexible Dynamics

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Alain G. de Souza ◽  
Luiz C. G. de Souza
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Center Of Mass ◽  
Rigid Motion ◽  
Linear Quadratic Regulator ◽  
Comparative Investigation ◽  
Attitude Control System ◽  
Linear Quadratic ◽  
Deformable Structure ◽  
Fuel Slosh

The design of the spacecraft Attitude Control System (ACS) becomes more complex when the spacecraft has different type of components like, flexible solar panels, antennas, mechanical manipulators and tanks with fuel. The interaction between the fuel slosh motion, the panel’s flexible motion and the satellite rigid motion during translational and/or rotational manoeuvre can change the spacecraft center of mass position damaging the ACS pointing accuracy. This type of problem can be considered as a Fluid-Structure Interaction (FSI) where some movable or deformable structure interacts with an internal fluid. This paper develops a mathematical model for a rigid-flexible satellite with tank with fuel. The slosh dynamics is modelled using a common pendulum model and it is considered to be unactuated. The control inputs are defined by a transverse body fixed force and a moment about the centre of mass. A comparative investigation designing the satellite ACS by the Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian (LQG) methods is done. One has obtained a significant improvement in the satellite ACS performance and robustness of what has been done previously, since it controls the rigid-flexible satellite and the fuel slosh motion, simultaneously.

Comparative assessment of the dynamics of the incidence of pulmonary and etraulmonary tuberculosis in St. Petersburg for half a century of observation

MedAlliance ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 6-14
Keyword(s):  
Control System ◽  
Incidence Rate ◽  
Extrapulmonary Tuberculosis ◽  
High Rate ◽  
Tb Control ◽  
Complete Restoration ◽  
Third Stage ◽  
High Level ◽  
Clinical Awareness ◽  
Positive Effect

This article describes the results of comparative analysis of the dynamics of incidence of pulmonary tuberculo-sis (TBP), extrapulmonary extrarespiratory tuberculo-sis (TBER) and respiratory extrapulmonary tuberculosis (TBREP) in St. Petersburg (Leningrad) from 1970 to 2019. Throughout the 50 years of observation, epidemiological situation for TBP, especially for TBER, hasmuch improved, with incidence of the latter going down 30 times. Five stages (decades) were identified, within which the factors demonstrate practically the same impact, the growth rate of indicators was calculated for each stage (the value of indicators at the beginning of each stage taken as 100%).The first stage was a simultaneous reduction in the inci-dence rate in all categories of TB localization against the background of socio-economic factors positive effect and organization of effective and comprehensive an-ti-TB measures. In the second stage (1980ies, a period of growing socio-economic problems), the positive dynam-ics of TB incidence stopped and switched to stabilization at a low level. Indicators became more volatile, while TB dynamics by localization more and more desynchro-nized. Тhe third stage (1990iеs, a period of social and economic crisis) was char-acterised by a sharp increase of TB incidence, especially TBREP, with a switch to stabi-lization at a high level. The fourth stage (2000 through 2009, the beginning of TB control system restoration) demonstrated the indicators’ dynamics desynchroniza-tion: the incidence of TBP and TBREP has stabilized, and TBER continued to decline. The fifth stage (2009 through 2019, complete restoration of TB control system) showed a steady trend of incidence rate reduction and return of uniformity in incidence rate of various localizations.There is no increase in the proportion of extrapulmonary TB expected for the incidence decline. TBER incidence had been declining in most stages, with the exception of the 90ies, which could be explained by substandard work in identifying patients, and the rarity of TBER etiological verification. It is necessary to raise the clinical awareness of narrow specialists and general practitioners in the di-agnostic problems associated with TBER.The coincidence of the rate of TB incidence decrease in main localizations in the 1970ies and 2010s proves that a comprehensive state strategy to combat tuberculosis can provide a high rate of TB incidence decrease in various social layers with positive social and economic conditions of life of the population.

Energy consumption optimization for AC drives position control

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Branislav Ftorek ◽  
Milan Saga ◽  
Pavol Orsansky ◽  
Jan Vittek ◽  
Peter Butko
Keyword(s):  
Control System ◽  
Energy Saving ◽  
Energy Savings ◽  
Position Control ◽  
Control Strategies ◽  
Content Type ◽  
Ac Drives ◽  
Energy Demands ◽  
Wide Range ◽  
Energy Consumption Optimization

Purpose The main purpose of this paper is to evaluate the two energy saving position control strategies for AC drives valid for a wide range of boundary conditions including an analysis of their energy expenses. Design/methodology/approach For energy demands analysis, the optimal energy control based on mechanical and electrical losses minimization is compared with the near-optimal one based on symmetrical trapezoidal speed profile. Both control strategies respect prescribed maneuver time and define acceleration profile for preplanned rest-to-rest maneuver. Findings Presented simulations confirm lower total energy expenditures of energy optimal control if compared with near-optimal one, but the differences are only small due to the fact that two energy saving strategies are compared. Research limitations/implications Developed overall control system consisting of energy saving profile generator, pre-compensator and position control system respecting principles of field-oriented control is capable to track precomputed state variables precisely. Practical implications Energy demands of both control strategies are verified and compared to simulations and preliminary experiments. The possibilities of energy savings were confirmed for both control strategies. Originality/value Experimental verification of designed control structure is sufficiently promising and confirmed assumed energy savings.

scholarly journals Non-coplanar interplanetary flight simulation considering motion relative to the center of mass peculiarities of solar sail spacecraft

2020 ◽  
Vol 4 (3) ◽  
pp. 141-150
Author(s):  
R. M. Khabibullin ◽  
O. L. Starinova
Keyword(s):  
Thin Film ◽  
Center Of Mass ◽  
Control Program ◽  
Solar Sail ◽  
Flight Simulation ◽  
Light Pressure ◽  
Second Stage ◽  
Third Stage ◽  
Angular Velocities ◽  
The Hill

The paper is devoted to the non-coplanar interplanetary Earth–Venus flight of a spacecraft equipped with a non-perfectly reflecting solar sail, the magnitude and direction of acceleration from which is calculated taking into account specular and diffuse reflections, absorption and transmission of photons by the surface of the solar sail. The goal of the heliocentric motion is to transfer the solar sail spacecraft into the Hill sphere of Venus with zero hyperbolic excess of speed. A feature of the paper is the study of the motion of a non-perfectly reflecting solar sail spacecraft taking into account the motion relative to the center of mass. The problem is divided into three stages. At the first stage, a nominal program for controlling the motion of the spacecraft center of mass is formed. At the second stage, sufficient angular velocities are determined to ensure the obtained nominal control program and the parameters of the spacecraft controls – thin-film controls located along the perimeter of the solar sail – are calculated. The operating principle of the thin-film controls is quite simple. When the voltage applied to the thin-film controls changes, they become transparent or opaque, there is a difference in the normal components of the light pressure forces, which provides a control torque for changing the orientation of the spacecraft in space. At the third stage, the joint motion of the center of mass and relative to the center of mass of the spacecraft is simulated to demonstrate the feasibility of the obtained control program. As a result, a comparison is made of non-coplanar interplanetary Earth–Venus flights with and without thin-film control elements.

scholarly journals Experimental implementation of artificial neural network-based active vibration control & chatter suppression

2021 ◽  
Author(s):  
Yong Xia
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Network ◽  
Control System ◽  
Vibration Control ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Chatter Suppression ◽  
Active Vibration ◽  
Artificial Neural

Vibration control strategies strive to reduce the effect of harmful vibrations such as machining chatter. In general, these strategies are classified as passive or active. While passive vibration control techniques are generally less complex, there is a limit to their effectiveness. Active vibration control strategies, which work by providing an additional energy supply to vibration systems, on the other hand, require more complex algorithms but can be very effective. In this work, a novel artificial neural network-based active vibration control system has been developed. The developed system can detect the sinusoidal vibration component with the highest power and suppress it in one control cycle, and in subsequent cycles, sinusoidal signals with the next highest power will be suppressed. With artificial neural networks trained to cover enough frequency and amplitude ranges, most of the original vibration can be suppressed. The efficiency of the proposed methodology has been verified experimentally in the vibration control of a cantilever beam. Artificial neural networks can be trained automatically for updated time delays in the system when necessary. Experimental results show that the developed active vibration control system is real time, adaptable, robust, effective and easy to be implemented. Finally, an experimental setup of chatter suppression for a lathe has been successfully implemented, and the successful techniques used in the previous artificial neural network-based active vibration control system have been utilized for active chatter suppression in turning.

scholarly journals Analysis of Platform Leveling Systems for Tracked Feller-Buncher Machines

Inventions ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 96
Author(s):  
Andronov Alexandr ◽  
Bacherikov Ivan ◽  
Zverev Igor
Keyword(s):  
Mathematical Model ◽  
Center Of Mass ◽  
Slope Angle ◽  
Hydraulic Cylinder ◽  
Second Stage ◽  
Modeling Methods ◽  
The Third ◽  
Support Reaction ◽  
Third Stage ◽  
The Stability

The study was devoted to the analysis of feller buncher platform leveling systems. The widespread use of these systems in the design of modern feller-buncher machines makes the study relevant to assess operational efficiency. The analysis was conducted in five stages using analytical and stochastic mathematical modeling methods. In the first stage, the existing layouts of alignment systems were analyzed from the position of force on the hydraulic cylinder rods of the platform tilt drive. The three-cylinder layout scheme, where the force on the hydraulic cylinder rod was 50…60% less than that on the two-cylinder layout, appeared to be the most expedient. In the second stage, a mathematical model for determining changes in the position of the center of mass of the feller-buncher depending on the inclination angle of the platform was derived. In the third stage, a mathematical model was derived for determining the limiting angle of slope of the terrain when the feller buncher moved up the slope. For this purpose, two calculation schemes were considered when the machine moved up the slope without and with a tilted platform. Zero support reaction on the front roller was taken as the stability criterion. In the fourth stage, a mathematical model for determining the limiting angle of slope of the terrain during the roll of the feller-buncher machine was obtained. In the fifth stage, the efficiency of the application of leveling systems was evaluated. A graph of the dependence of changes in the terrain slope angle on the platform slope angle was plotted, and a regression dependence for an approximate estimate was obtained. A regression analysis was also carried out, and dependencies were obtained to determine the weight of a feller-buncher with a leveling system and the added pressure on the ground caused by the increase in the weight of the base machine. The analysis of platform leveling systems showed the effectiveness of their application in the designs of feller-buncher machines, as it allows the machines to work on slopes with an inclination of 50…60% more than without them.

scholarly journals The control system of the yeast drying process

2018 ◽  
Vol 241 ◽  
pp. 01022 ◽  
Author(s):  
Piotr Wolszczak ◽  
Waldemar Samociuk
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Temperature Control ◽  
Object Identification ◽  
Control Methods ◽  
Drying Process ◽  
Process Flow ◽  
Non Linear ◽  
Linear Object

The article presents the results of choosing how to control a real non-linear object. Yeast drying requires a precise temperature control due to the possibility of overheating. The object changes properties during of the process flow. Object identification is used and a mathematical model is developed. The model is used to select roboust control methods. The results are compared to the system of two PID regulators used in practice.

scholarly journals Performance Assessment of Cascade Control System with Non-Gaussian Disturbance Based on Minimum Entropy

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 379 ◽  
Author(s):  
Qian Zhang ◽  
Ya-Gang Wang ◽  
Fei-Fei Lee ◽  
Wei Zhang ◽  
Qiu Chen
Keyword(s):  
Control System ◽  
Performance Assessment ◽  
Chemical Engineering ◽  
Control Strategies ◽  
Thermal Power ◽  
Cascade Control ◽  
Effective Control ◽  
Minimum Entropy ◽  
Non Gaussian ◽  
Cascade Control System

Due to the fact that cascade control can improve the single-loop’s performance well and reduce the integral error from disturbance response, it has been one of the most important control strategies in industrial production, especially in thermal power plant and chemical engineering. However, most of the existing research is based on the Gaussian system and other few studies on the non-Gaussian cascade disturbance system also have obvious defects. In this paper, an effective control loop performance assessment (CPA) of cascade control system for many non-Gaussian distributions even the unknown mixture disturbance noise has been proposed. Compared to the minimum variance control (MVC) approach, the minimum entropy control (MEC) method can obtain a more accurate estimate. In this method, like MVC, the primary loop output and secondary loop output can be represented as invariant and dependent terms, then adopted estimated distribution algorithm (EDA) is used to achieve the system model and disturbances. In order to show the effectiveness of MEC, some simulation examples based on different perturbations are given.

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