Uncontrolled Disturbances Research Articles

Control problem for a parabolic system with disturbances and possible changes in dynamics

The problem of control of a parabolic system, which describes the heating of a given number of non-uniform rods, is considered. The control is point heat sources, which are located at the ends of the rods. Some boundary conditions are affected by uncontrolled disturbances. The density functions of the internal heat sources of the rods are not exactly known, but the segments of their change are given. We admit that at some moments of time, changes may occur in the equations describing the dynamics of the controlled system. These moments of time are not known in advance. The goal of choosing the control is to ensure that at a fixed moment of time, the weighted sum of the average temperatures of the rods belongs to a given segment for any admissible realizations of disturbances, unknown functions and moments of change in the dynamics. After the change of variables, this problem is reduced to a one-dimensional control problem with disturbance. Necessary and sufficient termination conditions are found.

Системно-синергетический анализ и синтез управляемого процесса резания

Currently, good progress has been produced in the creation of machine tools with CNC computer systems. They are able to ensure the coincidence of program and the trajectories of the actuators with high accuracy. But when manufacturing parts with the same accuracy it becomes possible in rare circumstances. This is because of the necessity to take into account the entire controlled dynamic cutting system when manufacturing parts, while the quality of the part depends on various physical interactions under process work. In contrast to the well-known research and development, the paper focuses on the fact that the modeling level is based on a system-synergetic representation, which includes the procedure of expansion – compression of the state space. The system takes into account elastic deformations of its elements, evolutionary changes in their properties, uncontrollable disturbances, revealing physical interactions. This is a complex system, where its individual coordinates of the state depend on programmable trajectories first of all, secondly, they are characterized by internal connections and self-organization, and finally, they affect the output properties of cutting. The output properties include parts quality parameters and specified costs for parts manufacture. The article describes the main provisions of the synergetic system analysis and synthesis of a dynamic cutting system control, provides its mathematical modeling, views a simple procedure for analyzing and synthesizing a model. The example of practical application has been also observed.

Study of Clinical Profile, Management and Outcome of Patients Presented with Seizures in Emergency Medicine Department

Background: Seizures are sudden, uncontrolled electrical disturbances in the brain that causes widerange of symptoms. Predominant causes are CNS infection, trauma, space occupying lesion, cerebrovascular accidentsetc. The goal of the emergency clinician is to differentiate seizures from mimics andidentify reversible causes.Management focuses on identifying reversible causes such as hypoxia, hypoglycemia and initiating pharmacological treatment. Aim: The aim is to study different variablesrelated to clinical profile, management and outcome of the patients presenting with seizures inEmergency Department (ED).Material & Methods: We conducted a prospective observational studyon 200 patients who presented with seizures in the emergency medicine department according toinclusion and exclusion criteria from September 2020-October 2021. In all patients of our study, primary and secondary surveys along with immediate resuscitation were done. A brief history, clinical examination and all necessary hematological and radiological investigations were done. Patients weretreated accordingly and followed-up until discharge or death.Results: Out of 200, 73% patients weremales and 27% were females. Mean age of study population was 49.3 years. Idiopathic(26%) was theleading cause followed by alcohol withdrawal seizure(20%) and cardio-vascular accident (13%) withgeneralized tonic clonic seizures (GTCS) being the commonest type (67%). Majority of patients(95%) were treated with anti-epileptic drugs (AEDs).Conclusion:Along with immediate primaryresuscitation, early identification, prevention of recurrence and treating the cause forms the basis ofmanagement of seizures in emergency department. Key Words: Seizure, Management, Idiopathic, Emergency department

Investigation of smart thermostat fault detection and diagnosis potential for air-conditioning systems using a Modelica/EnergyPlus co-simulation approach

Smart thermostats offer low-cost alternative for fault detection and diagnosis (FDD) in residential air-conditioning (AC) systems. However, smart thermostats do not directly measure AC performance, but measures indoor air conditions which reflect the indoor air responses to both AC operations and other factors like weather and building gains. Estimating uncontrollable building gain disturbances is essential to differentiate them from AC impacts. Since the uncontrollable disturbances are difficult to monitor using smart thermostat data, there is need to investigate the actual capability of smart thermostats for FDD. In this study, an integrated building and Vapor Compression cycle-based AC model was developed and simulated using EnergyPlus/Spawn and Dymola. The simulation was performed under ten scenarios covering relevant gains, low charge, and low indoor airflow faults. The sensitivity of the time-to-cool feature under these scenarios was studied. The results show about 10% time-to-cool increase from varied internal gains and infiltration. Meanwhile, low charge at 10%, 20% and 30% severity increased time-to-cool by about 3%, 6%, and 20%, respectively, suggesting that if these gains are neglected in an FDD method, it might not be possible to detect low charge below 30% using smart thermostat data since even without a fault, the combined impact of those gains already exceeded that for 20% low charge. For low indoor airflow at 10%, 20% and 30% severity, the increase in time-to-cool was about 3%, 9% and 12%, meaning that only low indoor airflow fault above 30% can be confidently detected if those gains are not captured. Thus, this study demonstrates the need to consider some of these gains in developing smart thermostat based FDD algorithms.

ПРОДОВОЛЬЧА БЕЗПЕКА: ГЕНЕЗИС ТА СУЧАСНІ ПРІОРИТЕТИ ЗАБЕЗПЕЧЕННЯ

The need to satisfy the need for food was and remains a priority for every person. Despite significant technological progress, when knowledge and information are considered more valuable resources compared to limited natural resources, the problem of ensuring food security in the future remains unsolved. The growth of the planet's population with increasing negative impact on the natural environment makes it difficult to meet the primary need for food for every person. Physical and mental activity cannot be achieved solely due to the availability of any food, it is about caloric systematic nutrition taking into account individual properties. The purpose of the research is to clarify the historical moments and modern trends in the interpretation of the concept of "food safety" in order to create the necessary basis for understanding the essence of this category. In order to clarify the theoretical basis for ensuring food security, the following methods were used: induction and deduction, comparison and systematization – in the study of the essential characteristics of the term "food security"; synthesis and analysis – to characterize the critically high share of income spent on food products in Ukraine; morphological analysis – for the prerequisites of supplementing the understanding of food security; graphic – for visual representation of theoretical and methodical material; abstract-logical – for theoretical generalizations and research conclusions. In the course of tracing the genesis of the perception of food security, it was found that the content of this category was characterized by constant rethinking, i.e. from the need to create physical availability of food to a clear formulation of requirements regarding caloric content and food safety. It has been proven that ensuring food security cannot be fully implemented at any of the hierarchical levels. Yes, the priority is food self-sufficiency of each country, but the full satisfaction of food needs cannot be realized without the import of certain food products. Hunger stimulates migration processes, therefore the implementation of international programs ensures the reduction of the risk of uncontrolled social disturbances. The conducted generalizations became the basis for modernizing the interpretation of the concept of "food safety" and provided the necessary theoretical basis for further scientific research.

Hardware implementation of deep neural network for seizure prediction

Epilepsy is a neurological disorder characterized by seizures, which are caused by a sudden, uncontrollable electrical disturbance in the brain. Recently, machine learning and deep learning techniques have been used in seizure prediction algorithms, which greatly aids epilepsy patients. Moreover, the usage of hardware that is available for both medical practitioners and epilepsy patients would help enhance the quality of life for epilepsy patients. For this purpose, a Field-programmable Gate Array (FPGA) is used in this work to implement a hardware model of a neural network that is able to predict seizures. In this research, the main aim is to implement an FPGA-based general and patient-specific seizure prediction algorithm that detects seizures for epilepsy patients using Multilayer Perceptron (MLP) neural network models. Moreover, the work will also tackle ways to optimize the FPGA resources and the computational time of the seizure prediction models. The data available for training and testing are raw electroencephalogram (EEG) signal samples provided by the Melbourne-NeuroVista seizure trial and the Melbourne-University AES-MathWorks-NIH Seizure Prediction Challenge. The results show that the general model had an Area under curve (AUC) score of 0.72 while the patient-specific model had an average AUC score of 0.8.

ОПТИМАЛЬНІ ОЦІНКИ ВЕКТОРА СТАНУ ДЛЯ ДИСКРЕТНИХ СТОХАСТИЧНИХ СИСТЕМ З НЕВИЗНАЧЕНИМИ ЗБУРЕННЯМИ ТА ШУМОМ

Assessment of the dynamic systems state is widely used in various areas of technical activity. In practice, the most well-known and common methods of estimation are the methods of the Kalman filter and Luenberger observers. Most of the results known in the scientific literature for constructing estimates of the dynamic systems state in the presence of acting uncontrolled disturbances and noise are associated with stationary systems. The insensitivity of such estimates to the influence of accompanying uncontrolled perturbations is ensured by the introduction of certain restrictions that are imposed on a number of system matrices, and their optimality is achieved by minimizing the estimation errors covariance matrix trace due to those degrees of freedom that remained after the separation procedure was performed. The aim of the work is to develop a filter capable of generating state vector optimal estimates of a stochastic linear system with changeable parameters that are insensitive to the influence of uncontrolled inputs. In this case, the conditions that guarantee the convergence of the estimates obtained must be easily verifiable. The goal is achieved by using a one-to-one transformation of the equations of systems, followed by the application of the Kalman filter. The O'Reilly functional observer is used as the specified transformation. An example is given that illustrates the effectiveness of the proposed filter.

Probable Posterior Ischemic Optic Neuropathy Associated with Acute Fungal Sinusitis

Purpose: We report a case of probable posterior ischemic optic neuropathy in a patient with acute fungal sinusitis.Case Summary: An 81-year-old male patient presented with sudden-onset visual loss in his left eye 3 weeks prior to presentation. His best corrected visual acuity was 0.6 in his right eye and light perception in his left eye. Pupillary size was 3 mm in both eyes, and a relative afferent pupillary defect was detected in his left eye. In fundus examination, diabetic retinopathy was found, and cup/disc ratios were increased in both eyes, but disc swelling and hemorrhage were not observed. Fluorescein angiography did not indicate filling delay, defects, or leakage of discs in either eye. Magnetic resonance imaging of the brain revealed multi-sinusitis in the sphenoid, ethmoid, and frontal sinuses. No bony defects or erosion were found around the optic canal or orbital apex during endoscopic surgery; however, histological examination revealed aspergillosis. The patient was diagnosed with posterior ischemic optic neuropathy caused by acute fungal sinusitis.Conclusions: When elderly patients with uncontrolled diabetes experience sudden visual disturbances without ocular pain, posterior ischemic optic neuropathy with fungal sinusitis should be considered as a differential diagnosis. Immediate imaging studies and appropriate treatment should be performed.

The link between seizures and prolactin: A study on the effects of anticonvulsant medications on hyperprolactinemia in rats

Seizures are a common neurological disorder that affects people of all ages. These sudden, uncontrolled electrical disturbances in the brain can cause a variety of symptoms, including convulsions, loss of consciousness, and abnormal sensations. While seizures have long been recognized as a potential cause of hormonal imbalances, recent research has shed new light on the link between seizures and prolactin. The study involved 30 adult female Wistar rats, which were divided into a control group (treated with normal saline) and four treatment groups: chronic group (treated with 30 mg/kg pentylenetetrazol intraperitoneally three days a week for 10 weeks), chronic + Levetiracetam (50 mg/kg, gavage), chronic + Cabergoline (0.05 mg/kg, gavage), and chronic + Levetiracetam (25 mg/kg) + cabergoline (0.025). The drugs were administered three days a week for 10 weeks. Field action potentials were recorded from the CA1 area of the hippocampus using eLab after anesthetizing the animals with a ketamine-xylazine combination (70 +7 mg/kg). The prolactin levels were measured using the ELISA method after serum preparation. The findings indicate that the use of levetiracetam as an anticonvulsant drug resulted in a significant decrease in the amount of prolactin and spike number of convulsive activities compared to the chronic group. However, the amplitudes of convulsive activities did not show a significant difference between the control and other treatment groups. In conclusion, investigating the possibility of subclinical seizures and utilizing anticonvulsant medications in hyperprolactinemia that is resistant to treatment are crucial in treating infertility.

Methods for Damping Payload Oscillations and Robust Control of an Overhead Crane Trolley Considering the Dynamics of the Electric Drive

The control plant is a trolley of a single-girder overhead crane designed to move a suspended payload along the span. Features of the plant: one control with two degrees of freedom, the uncertainty of mass-inertial characteristics, and the action of non-smooth uncontrolled disturbances. We consider the reduced dynamics of the DC motor in the mathematical model, where the power supply voltage of the armature circuit is a control. Here, parametric and external disturbances affecting the mechanical subsystem become unmatched (i.e., they act through different channels with control) and cannot be directly compensated. This paper considers two main problems, each of which uses S-shaped smooth sigmoid functions with saturation. The first problem is to design the trajectory of the trolley considering the design constraints on its velocity and acceleration. Tracking such a trajectory should ensure the smooth transfer of the payload in a given time and the damping of its oscillations. For this purpose, a reference trajectory has been developed in the form of the sum of a sigmoid function and an integral of the swing angle. The proposed solution is not inferior in the efficiency to existing analogs, while its implementation requires less computational costs. The second problem is to develop a robust tracking system. For this purpose, a procedure for block synthesis of discontinuous true control and sigmoid fictitious controls (local feedbacks) has been developed. The latter are smooth analogs of discontinuous control and make it possible to suppress unmatched disturbances with a given accuracy without identifying them. In contrast to standard linear local feedbacks, the boundness of sigmoid fictitious controls does not lead to a large overshoot of state variables, which is critical in the presence of design constraints. In addition, such fictitious controls are implemented in mechanical plants and do not contribute to the wear of the actuator, which inevitably occurs when discontinuous fictitious controls are used. We presented the results of numerical simulation and carried out a comparative analysis of closed-loop systems with various fictitious controls: linear, discontinuous, and sigmoid. The results of the numerical simulation demonstrated the effectiveness of the developed approach.

Dynamic Models with Sigmoid Corrections to Generation of an Achievable 4D-Trajectory for a UAV and Estimating Wind Disturbances

For an unmanned aerial vehicle (UAV) of an aircraft type, the problems of planning achievable trajectories as well as robust control under wind disturbances are considered. A computationally simple method for compiling a primary non-smooth 4D trajectory is proposed. Its segments connect the given waypoints and determine the desired average velocity in various sections. Instead of time-consuming methods of analytical smoothing of broken path joints using polynomials, a tracking differentiator with S-shaped smooth and limited sigmoid corrective actions is developed. This virtual dynamic model provides natural smoothing of the primary trajectory considering the design constraints on the velocity, acceleration, and thrust of the UAV. The tracking differentiator variables create an achievable trajectory and are used to synthesize the UAV tracking system. To compensate for the action of wind disturbances on the UAV, a disturbance observer is developed. It is a replica of the equations of the control plant model, which are directly affected by external uncontrolled disturbances. These algorithms also use sigmoid corrections. Unlike standard disturbances observers, this approach does not require the development of a dynamic model of external disturbances and does not assume their smoothness. The effectiveness of the developed algorithms was confirmed by numerical simulation.

Problem of Controlling a Steam Generator under Uncertainty with Constraints on the Phase Variables and Controls

The problem of controlling a steam generator is considered, taking into account restrictions on the phase variables and control under the effect of external uncontrolled disturbances. To synthesize the control law, a block approach is used with the formation of linear local relationships with saturation, which makes it possible to take into account restrictions on phase variables and control when choosing feedback parameters. Under conditions of incomplete information about the state vector and under the effect of external disturbances, an observer of states and disturbances is synthesized, which makes it possible to obtain estimates of unknown signals with the given accuracy. The efficiency of the proposed algorithms is confirmed by the results of numerical simulation.

НЕЧІТКА ЕКСПЕРТНА СИСТЕМА ДЛЯ КЕРУВАННЯ ТЕМПЕРАТУРОЮ ПОВІТРЯ У ПРИМІЩЕННЯХ ТОРГОВЕЛЬНО-РОЗВАЖАЛЬНОГО ЦЕНТРУ

Abstract The article presents the stages of developing a fuzzy expert system for the operator of a heating point of a shopping and entertainment center. The principle of operation of the air heating system of the mall is shown, implemented using computer-integrated control with a SCADA system. For the effective operation of the air temperature control system in different areas of the mall, functions for belonging to comfort zones have been developed in terms of visitors and the requirements of sanitary standards. It is indicated that typical air temperature stabilization controllers cannot always provide the desired mode due to the influence of a large number of uncontrolled disturbances on the control system. In this case, in the absence of additional blocks for adapting control algorithms, it becomes expedient to remotely control the operator using a mnemonic diagram of the ventilation process. And to improve the efficiency of the process of remote control of thermal equipment, an expert system was proposed that implements the algorithm of I. Mamdani, to control the coolant flow valves. The controller receives information from the outdoor air and air temperature sensors in the control area of the mall. After processing the signals from the sensors, the controller transmits information to a computer with an expert system. Depending on the temperature and season of the year, the program calculates the optimal position of the valve (in percentage of stroke) for the flow rate of the coolant and recommends installing it to the operator. Also, it is shown that in the process of developing a fuzzy expert system, it is recommended to choose the Gaussian type of membership functions; minimal number of terms - sets - three functions of dependency; weight coefficient of each rule in the knowledge base is the same and equal to 100; the method of defasification is the method of the center of gravity. It is indicated that the introduction of expert advice to operators can also lead to a reduction in the response time to emergency situations up to 90% increase in the reliability of the equipment as a whole.

Determination of the radius of robust stability of the automatic pressure control system in the stabilization column of a catalytic reforming unit

It is proposed to take into account the influence of uncontrolled disturbances on the regulation of pressure in the stabilization column of a catalytic reforming unit by changing the coefficients of the denominator polynomial of the transfer function of the automatic pressure control system based on robust stability methods. To describe the problem in a general form, a general view of the polynomial of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer is obtained. The purpose of the study is to determine the maximum range of change in the coefficients of the polynomial of the denominator of the transfer function of an automatic pressure control system in the stabilization column of a catalytic reformer, at which robust stability is maintained. Methods - methods of robust stability, automatic control theory. A family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of a catalytic reformer with squared uncertainty parameters is considered.The problem of determining the area of robust stability of a family of polynomials is reduced to determining the areas of stability of four edge polynomials and the intersection of all areas to determine the area of robust stability of the family. In general, the problem of determining the robust stability of each edge polynomial is described. To determine the area of robust stability of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer, three polynomials, including the nominal one, are specified. Based on the general description of the problem, the radius of stability of each edge polynomial is determined using a graphical criterion and the construction of a Tsypkin-Polyak hodograph. Results - based on the intersection of the stability regions of four rib polynomials, the robust stability region of the family of polynomials of the denominator of the transfer function of the automatic pressure control system in the stabilization column of the catalytic reformer with a stability radius of 1.5 was determined. Conclusion - this result can be used in the development of an automatic pressure control system in the stabilization column of the catalytic reformer and the choice of regulator settings.

Identifying Epileptic Seizure by Optimized Feature Extraction Process Using the Method of Feature Fusion Technique

Epilepsy is a brain disorder that results in seizures; in general seizure is a suddenly occurring uncontrollable electrical disturbance in the brain. These disturbances in the brain can lead to changes in behaviour, feelings, movements, etc. It is highly essential for the patients suffering with epilepsy to be diagnosed and treated. The normal detection of epilepsy is done using EEG signals which are time consuming. This paper aims at proposing a methodology to diagnose epilepsy by the use of EEG signals by establishing a correlation between statistical calculations and EEG signals. A various set of features are applied to the epilepsy and non-epilepsy dataset. Features such as time domain frequency which include mean, skewness, variance, kurtosis, standard deviation, approximate entropy, zero crossings, power spectrum and frequency domain features that include signal energy and total signal area, average DWT coefficient, signal relation features and human brain graph features. Further, considering these features, feature fusion and optimization aka FFO is carried out which helps in analysing the features in an optimal way for further classification. Moreover, feature fusion and its optimization helps in exploring the new features that helps in enhancing the distinguish between classes. These features help diagnosis of the brain disorder in a very time efficient manner with higher accuracy. In this paper, we propose a feature fusion methodology for the most efficient working of the system.

Chain Network Control with Delay by an Auxiliary Loop Method

The article is devoted to the development of control algorithms for a network of agents of a chain network, each agent of which is a linear plant with state delay, subject to the action of external disturbances under conditions of a priori uncertainty. In each agent of the network, the output of the previous agent is monitored, and the signal from the leading subsystem arrives only at the first agent of the network, the communication is one-way. Taking into account the time delay in the models of each agent of the network of such a structure makes them close to real ones. In agent control systems, disturbances are compensated by implementing the principle of invariance, namely, in each network agent, compensation for the action of external disturbances acting on the network agent from the outside, as well as internal disturbances caused by various modes of operation of the plant, is carried out by generating a special disturbance signal, and then it subsequent compensation with the help of an auxiliary loop and Khalil observers. A numerical example of a chain network consisting of four linear control plants is given under the conditions of interval uncertainty of the parameters of their mathematical models, state delay and the action of external uncontrolled disturbances. Numerical simulation was carried out in Matlab Simulink. Graphs of transient processes for tracking errors of agents of the chain network are presented, confirming the theoretical conclusions and illustrating the good performance of the control algorithms for the chain network.

Управление сетью цепочной структуры с использованием метода вспомогательного контура в условиях больших по амплитуде возмущений

The article presents a solution to the problem of controlling a network of a chain structure, where each agent is a linear plant influenced by the action of external uncontrolled large-amplitude perturbations under a priori uncertainty. For a chain network the auxiliary loop method is used. In each agent of the network the output of the previous agent is monitored, and the signal from the leading subsystem arrives only at the first agent of the network. The control systems of each agent are built using the measured data on the output of the agent and the agent preceding it. Compensation for the effect of perturbations is carried out by generating a special signal that carries information about all perturbations of the system, and then damping it by an auxiliary loop. Since the problem can be solved using only the measured scalar input and output signals, then two observers of the variables of the system. should be used to obtain estimates of the derivatives of these signals necessary for the formation of control actions. Thus, the chosen control laws in each agent of the chain ensure the achievability of the control goal with the required dynamic accuracy. An example of a chain network with four linear control plants is given. The proposed control is applied to the network plant. Computer simulation was carried out in the Matlab Simulink environment. Tracking error transients are presented for each of the four agents of the chain network. The simulation results confirmed the theoretical conclusions and showed the effectiveness of the proposed chain network control law under external uncontrolled disturbances of large amplitude.

Synthesis of a Control System for a Waste Heat Boiler with Forced Circulation under Restrictions on Control Actions

As is often the case in practice, classical control theory does not fully provide sufficient tools for solving applied problems of a certain specific class. Such problems include automatic control of waste heat boilers where physical restrictions are imposed on controls, namely, they must belong to the class of non-negative functions with restrictions on amplitude and growth rate. In the theoretical part of this paper, within the framework of the block approach, methods for the synthesis of general linear systems with one-sided restrictions on control actions and state variables were developed. Then, the developed algorithms were applied to the waste heat boiler control system under conditions of incomplete measurements of state variables and the action of parametric and external uncontrolled disturbances. The effectiveness of the proposed algorithms was confirmed by numerical simulation.

Оптимізація програмованих траєкторій стабілізації рухомих обʼєктів на основі систем керування змінної структури

Розглядаються оптимальні системи, що забезпечують для динамічних систем високі показники якості керування: швидкість, точність та низьку енерговитратність. Розвивається підхід до синтезу робастно-оптимальних систем на основі використання зворотних звʼязків зі змінною структурою та включає такі основні етапи: планування програмної оптимальної траєкторії; визначення моментів перемикання керуючих функцій у ланцюгах зворотного звʼязку обʼєкта; синтез керуючих функцій у відповідних ланцюгах зворотного звʼязку багатовимірного обʼєкта. Застосування запропонованого порядку синтезу систем зі змінною структурою для різних типів обʼєктів на основі попередньої побудови оптимальних програмованих траєкторій стабілізації динамічних процесів дозволяє оптимізувати процеси стабілізації нелінійних нестаціонарних систем високого порядку. Оптимальні програмні траєкторії стабілізації формуються з відрізків, усталених відносно відповідної похідної координати руху, на основі поліноміальних форм для заданих граничних умов і критерію оптимальності з урахуванням обмежених значень керування і розвʼязується для часу моментів перемикання керуючих впливів і часу закінчення перехідного процесу на основі системи алгебраїчних рівнянь. Синтез керування проводиться з урахуванням початкових значень на основі рівнянь балансу сил і моментів, що діють на рухомий обʼєкт, та їх похідних. Оптимальні траєкторія та керування формуються таким чином, що задають при синтезі додаткового робастного контуру керування (зі зворотним звʼязком за виходом обʼєкта) для компенсації неповної визначеності математичної моделі та неконтрольованих (невимірюваних) збурень і шумів, достатньо обмежені області зміни координат рухомого обʼєкта відносно заданих значень. Це в подальшому дозволяє побудову достатньо ефективних та практичних в реалізації робастно-оптимальних систем керування, наприклад морськими рухомими обʼєктами, квадрокоптерами, що функціонуть в умовах неповної визначеності.

Penetration shape control with correction of the state variables evaluation during electron-beam welding by the level of active disturbances

Penetration shape during electron-beam welding is determined in the first approximation by the vapour plasma crater shape formed by the energy source. The inability to measure the parameters of penetration shape during electron-beam welding leads to their estimation by regression equations that establish a relationship with mode parameters. However, when welding mode parameters are stabilized, the instability of penetration shape remains due to the action of uncontrolled disturbances, which in some cases lead to unacceptable deviations. A possibility of the state variables evaluation correction during electron-beam welding, namely the depth penetration and the weld shape factor, by determining the “noise component”, is considered. Such correction is carried out by the discrepancy of any measured output variable, as the difference between its estimate according to a similar mathematical model and the measured value. As such output variable, the vapour plasma torch light intensity can be used. A control algorithm and a structural diagram of the automatic control system for weld penetration shape with correction of model assessment of the process state by the measured output have been developed.