Continuous Control Systems Research Articles

An Adaptive Dynamic Programming Scheme for Nonlinear Optimal Control With Unknown Dynamics and Its Application to Turbofan Engines

In this article, a novel adaptive dynamic programming (ADP) approach is proposed for the optimal control problem of nonlinear continuous control systems with unknown dynamics. First, an alternating iteration algorithm based on Hamilton-Jacobi-Bellman equation is proposed for the optimal control of known nonlinear control systems. Then, the convergence results of the alternating iteration algorithm are obtained by using mathematical induction and monotone bounded convergence theorem. Moreover, the global asymptotic stability of the nonlinear closed-loop system is proved. Second, based on the scheme of alternating iteration algorithm, an ADP algorithm for the optimal control problem with unknown nonlinear dynamic model is developed by using the basis function approximation method and Newton-Leibniz formula, which can update the control strategy online by utilizing input and output information of the system. In addition, the convergence analysis of the proposed ADP algorithm is derived. Finally, the feasibility of the established results is verified by two examples, and the ADP method is applied to the optimal tracking fuel control problem of turbofan engines.

The use of the localization method for calculation of the robust PID regulator parameters for unmanned aircraft servo motor

The problem of controlling a typical nonlinear servo motor of an unmanned aercraft with non-stationary parameters using a robust PID controller is considered. The procedure for calculating the parameters of a robust PID controller based on the localization method (further - LM PID controller) for continuous and discrete control systems is studied. The influence of disturbing factors (internal and external) acting on the servo motor is considered. It is established that the main perturbations acting on the servo drive include internal perturbations, which are changes in the time constant and its gain from the temperature of the environment and the quality of the supply voltage. The simulation in the class of linear and nonlinear continuous systems showed that a servo drive with a ML PID controller has the property of robustness in the working range of changes in both the input signal and the parameters of the servo drive and controller. Simulation results showing the research are presented. When describing a servo motor with an LM PID controller in the class of linear discrete systems, its robustness is limited by a narrow range of variation of both its parameters and the quantization period of the input signal. As the degree of uncertainty in the parameters of the servo motor increases (approaching the working range of their change), the discrete system loses stability. For the synthesis of robust control circuits of an unmanned aercraft with given characteristics, mathematical dependences of the settling time and static error of a typical servo motor with LM PID controller from the quantization period of the input signal and the degree of uncertainty in its parameters are presented.

АВТОМАТИЧНА СИСТЕМА БЕЗПЕРЕРВНОГО КОНТРОЛЮ СТАНУ НАСАДКИ ДОМЕННОГО ПОВІТРОНАГРІВАЧА

The analysis of the existing methods for assessing the hot blast stove state, in particular its checkerwork was carried out. Based on the existing methods, the task of creating an automatic control system of the hot blast stove checkerwork state was set. The main operational parameters of the hot blast stove affecting the efficiency of its operation were selected. The structure of an automatic continuous control system of the hot blast stove state was developed, which includescontinuous monitoring of the differential pressure in the nozzle, the casing temperature various levels, and the composition of the exhaust gases. Selected modern automation equipment. Using adatabase of the values of the main technological parameters of the operation of a real hot blast stoves block, a regression dependence was built, allowing to calculate the efficiency of each of thehot blast stoves. It was found that the regression dependence also shows the "direction" and the degree of influence of each operating parameter on the heat engineering efficiency of the hot blaststove. The calculation of the efficiency for each hot blast stove was performed. A comparative analysis of the calculated efficiency with technological efficiency was carried out. It was shown thatthe calculated value practically coincides with the technological value. With the possibility of obtaining regression dependences of the efficiency and nozzle resistance on the main parameters characterizing the nozzle and blast heating, in real time it is possible to predict the dynamics of the hot blast stove state or to simulate various modes of operation of the unit. According to the results of the research, it is arguable that the developed control system can be successfully implemented and used in the blast furnace process.

Motor Imagery Based Continuous Teleoperation Robot Control with Tactile Feedback

Brain computer interface (BCI) adopts human brain signals to control external devices directly without using normal neural pathway. Recent study has explored many applications, such as controlling a teleoperation robot by electroencephalography (EEG) signals. However, utilizing the motor imagery EEG-based BCI to perform teleoperation for reach and grasp task still has many difficulties, especially in continuous multidimensional control of robot and tactile feedback. In this research, a motor imagery EEG-based continuous teleoperation robot control system with tactile feedback was proposed. Firstly, mental imagination of different hand movements was translated into continuous command to control the remote robotic arm to reach the hover area of the target through a wireless local area network (LAN). Then, the robotic arm automatically completed the task of grasping the target. Meanwhile, the tactile information of remote robotic gripper was detected and converted to the feedback command. Finally, the vibrotactile stimulus was supplied to users to improve their telepresence. Experimental results demonstrate the feasibility of using the motor imagery EEG acquired by wireless portable equipment to realize the continuous teleoperation robot control system to finish the reach and grasp task. The average two-dimensional continuous control success rates for online Task 1 and Task 2 of the six subjects were 78.0% ± 6.1% and 66.2% ± 6.0%, respectively. Furthermore, compared with the traditional EEG triggered robot control using the predefined trajectory, the continuous fully two-dimensional control can not only improve the teleoperation robot system’s efficiency but also give the subject a more natural control which is critical to human–machine interaction (HMI). In addition, vibrotactile stimulus can improve the operator’s telepresence and task performance.

CONTROLLABILITY AND GRAMIANS OF 2D CONTINUOUS TIME LINEAR SYSTEMS

The controllability of a class of 2D linear time varying continuous time control systems is studied. The state space representation is provided and the formulas of the states and the input-output map of these systems are derived. The fundamental concepts of controllability and reachability are analysed and suitable controllability and reachability Gramians are constructed to characterize the controllable and the reachable time varying systems. In the case of time invariant 2D systems, some algorithms are developed to calculate different controllability Gramians as solutions of adequate Lyapunov type equations. Corresponding Matlab programs are implemented to solve these Lyapunov equations.

Снижение мощности высокочастотных помех в сигнале управления автоматических систем гребенчатыми фильтрами

The article addresses the matter of reducing the power of high-frequency noise in the control signal produced by industrial automatic systems through the use of algorithms implementing the properties of comb filters in microprocessor controllers. The specific features relating to the frequency responses of open- and closed-loop automatic control systems of industrial facilities are analyzed - both taken alone and in combination with the characteristics of comb filters. The frequency properties of three filter groups that are conventionally used in continuous automatic control systems are compared with three groups of comb filters that implement similar functions. As applied to control tasks, such filters include real differentiating sections or first-order high-pass filters, first-order lag sections or low-pass filters, and proportional sections. The ratios between the parameters of continuous filters and comb filters at which their frequency properties coincide in the operating frequency band are determined. These ratios known, it becomes possible to synthesize the controllers of systems using the existing techniques. It is shown that the amplitude-frequency responses of comb filters have dips in the high-frequency band, due to which the high frequency noise power is finally decreased by up to 30%. The advantage of comb filters in control systems lies in simplicity of implementing them in digital form in a microprocessor controller. The application of comb filters in automatic control systems makes it possible to cut undesirable harmonic noise of large amplitude in the control signal.

Gıda Endüstrisinde Kullanılmak Üzere Keggin Tipi Polioksometalat/İletken Polimer Kompozitine Dayalı Glukoz Sensörü Hazırlanması

Otomasyonun gerektirdiği sürekli izleme ve kontrol sistemlerinde biyosensörler hassasiyetleri, kararlılıkları, kullanım kolaylıkları ve cevap hızları ile büyük ölçüde avantaj sağlamaktadır. Bu çalışmada, sektörün ihtiyaçlarını karşılamak üzere Keggin tip Polioksometalat (POM), (nBu4N)3[PW9O34(tBuSiOH)3], varlığında amino grubuna sahip karbazol türevinin (3-amino-9-etilkarbazol (AAC)) elektrokimyasal polimerizasyonu tarafından hazırlanan kompozit filme dayalı yeni amperometrik glukoz sensörü geliştirilmiştir. POM/PAAC kompozit ile modifiye edilen yüzeye Glukoz Oksidaz (GOx) enzimi immobilize edilerek enzimatik biyosensör hazırlanmıştır. Biyosensörün hazırlama ve çalışma koşulları optimize edilerek analitik karakterizasyonları gerçekleştirilmiştir. POM/PAAC-GOx modifiyeli yüzeylerin farklı derişimlerdeki glukoz miktarına karşı -0.7 V(Ag/AgCl) potansiyelde elektrokimyasal yanıtları incelenmiştir. Kısa zamanda hazırlanabilen bu yüzeylerden elde edilen veriler incelendiğinde kola ve meyve suyu gibi gıda örneklerindeki glukoz varlığına karşı hassas olduğu belirlenmiştir. Bu çalışmanın literatüre ve endüstriye kattığı yenilik hem düşürülen cevap süresi hem de biyosensörün hazırlanması için geliştirilen yöntemdir. Gıdalardaki glukoz içeriğinin belirlenmesinde yüksek doğrusallık, kısa cevap süresi ve uzun raf ömrü avantajlarının yanı sıra kolay hazırlana bilirliği, uygulamada kolaylık sunması, ölçümlerde zaman ve kimyasallardan kazanım sağlamasıyla ekonomik bir alternatif olacağı düşünülmektedir.

Wheel Slip Control for the Electric Vehicle With In-Wheel Motors: Variable Structure and Sliding Mode Methods

The article introduces four variants of the controller design for a continuous wheel slip control (WSC) system developed for the full electric vehicle equipped with individual in-wheel motors for each wheel. The study includes explanation of the WSC architecture, design of controllers, and their validation on road tests. The investigated WSC design variants use variable-structure proportional-integral, first-order sliding mode, integral sliding mode controllers as well as continuous twisting algorithm. To compare their functionality, a benchmark procedure is proposed based on several performance factors responsible for driving safety, driving comfort, and control quality. The controllers are compared by the results of validation tests done on low-friction road surface.

Semi-continuous electrochemical extraction of lithium from brine using CF-NMMO/AC asymmetric hybrid capacitors

Compared to traditional extraction of lithium using solar evaporation, the electrochemical extraction is advantageous in many aspects, including elevated efficiency, superior selectivity, and low environmental pollution. In this study, LiNi0·038Mo0·012Mn1·95O4 (LNMMO) with good lattice structure and nano morphology was successfully prepared and confirmed by XRD (X-ray diffraction), SEM-Mapping (scanning electron microscope mapping), SEM (scanning electron microscope), and EDX (Energy-dispersive X-ray spectroscopy) analyses. The pairing of LNMMO with activated carbon (AC) yielded obvious cost-effective and environmentally friendly composite when compared to conventional Noble metals used for battery anodes, such as Ag and Pt. A hybrid supercapacitor was assembled using delithiated LNMMO cathode (NMMO) and AC anode to form NMMO/AC. The cell showed high capacity, high rate performance, and excellent cyclic stability. A continuous flow NMMO/AC hybrid supercapacitor (CF-NMMO/AC) was developed for selective capture of Li+ in aqueous solution by combining NMMO/AC hybrid supercapacitor with self-designed continuous flow control system. The device delivered high Li+ extraction efficiencies reaching 14.4 mg/g per one cycle in simulated brine by consuming only 7.91 W h/mol Li+. The overall process produced 97.2％ Li+ in simulated brine at optimized operating conditions. Overall, CF-NMMO/AC system provided higher efficiency, superior selectivity, and moderate energy utilization for Li+ recovery from brine.

Modification of the solar heating system diagnostic method under operating conditions

One of the problems with the operation of solar heating systems is the variable capacity of the system dependent on the prevailing operating conditions. One of the methods for increasing the capacity of a solar system is to control the volume flow of the working medium. Volume flow of working medium in solar heating installation should be follow operating conditions. Designing a continuous control system based eg. on the PID controller requires knowledge of the dynamic properties of a solar system under operating conditions: gain coefficient, equivalent time constant and delay time of the solar collector response to a change in solar radiation intensity and the inlet temperature of a working medium. To date, the delay time has been omitted in the analyses. It is necessary to know the value of the delay time for proper design of the solar system controls, because the object response cannot be simultaneous with the moment of the input function. The paper presents the method for determining the dynamic properties of a solar system under operating conditions. The method is based on the comparison of two models: an analog model based on the energy balance of a collector and a digital model developed with the use of parametric identification based on a short-term measurement of solar radiation intensity and working medium temperatures. In the collector analog model, on the basis of the design and operating parameters of the collector, the transport delay time has been defined, which is an innovative aspect of this study. The modified analog collector model was verified on the basis of the step response determined experimentally in accordance with the applicable ISO 9806: 2017 standard. A very good convergence of the model with actual data was achieved for the time constant – 87%, effective thermal capacity – 85.9%, and the delay time – 96%. Practical application of the modified diagnostic method is presented on the example of a solar heating system composed of five flat-plate collectors with a total absorber area of 10 m2.

PREVENTIVE METHODS IN REDUCTION OF MASTITIS PATHOGENS IN DAIRY COWS

Mammary gland tissue inflammation (mastitis) is the most frequent disease in dairy cattle in the world, and negatively influences the milk quality having consequences for the dairy processing industry. The aim of the study was analyze designed preventive and control methods focused to reduction of mastitis in herd of Slovak pied cattle in the east of Slovakia during two years of experiment. From 180 cows at quarterly intervals in the 3rd, 6th, 9th and 12th month was performed a complex examination of health udder including an assessment clinical signs of mammary gland, abnormal udder secretions, Californian Mastitis Test (CMT) with subsequent collecting of milk samples for bacteriological examination. In the first year during the first two complex examinations, treatment of mastitis caused by coagulase positive staphylococci (S. aureus), coagulase negative staphylococci (S. haemolyticus, S. warneri, S. epidermidis) and Str. agalactiae, a reduction in prevalence from the original 41.3 % to 32.1 % was achieved. During the last two complex examinations in the first year the prevalence decreased to 25.2 % and then at the end to 21.1 %, respectively. The reduction of mastitis during the second year is characterized by a 22.1 %, 19.2 %, 12.2 % to 7.3 % mastitis, when the prevalence dropped by 5.5 %, respectively. Coagulase negative staphylococci and Str. agalactiae were the most numerous in each case during the second year and their occurrence subject to a proportional reduction. Proposed antimastitis methods and their implementation of continuous mastitis control system during two years, significantly reduced prevalence of mastitis by 34.0 % and influenced the occurrence of the most common pathogens of the mammary gland in monitored herd of dairy cows. Recorded reduction of mastitis in monitored dairy herd is an example of using available scientifically validated methods in a rationally compiled mastitis control program for the specific conditions of each dairy farm in the long period.

Modernization of time scale control unit for «Glonass-K» spacecrafts

Navigation spacecraft’s atomic clocks suffer from sudden small frequency jumps. These jumps lead to a decrease of user’s positioning accuracy and should be considered. Traditional method to detect these frequency jumps with the use of ground control segment does not ensure early user alert of increasing range error. A perspective way to improve global navigation satellite system’s signal integrity is the use of satellite on-board autonomous system for continuous control of board synchronization equipment time scale. This paper describes a novel diagram of frequency comparator – the main element of such system. The main difference of proposed solution is an application of time-to-digital converter for estimation of time error which allows to decrease mass, dimensions and power consumption. The paper deals with the particularities of direct frequency comparator implementation for on-board equipment of space vehicle and describes structure of implemented breadboard model.

Hydroacoustic Rupture-Detection System for Major Underwater Pipelines

In modern conditions, a continuous monitoring system for major underwater pipelines is an essential part for maintenance of their normal operating. One of the possible approaches to the development of a continuous control system for the pipeline technical condition can be the method that is based on the luminal echo sounding. The work contains numerical experiments for the analysis of influence of leaks and ruptures of gas pipelines on the structure of the illuminated acoustic fields in conditions of natural stochasity of water environment. In the quantitative experiment, the emitter was located on the axis of underwater acoustic channel (UAC). In this case, all the acoustic energy spreads along the UAC axis and there are no shade zones. As a result of the numeric experiments, correlations between the acoustic field distribution along the axis of underwater acoustic channel with and without gas pipeline ruptures at the range of 1 km and different levels of the random componentry were obtained. In the numeric experiment, the random componentry of the acoustic velocity field was discretely changing from 0,05 m/s to 0,5 m/s. The pipeline rupture was modelled at the ranges of 35; 70; 100 km. Pipeline rupture shifts the UAC axis; consequently, the acoustic field range rapidly drops at the depth of emitter. This effect is observed at all levels of the random componentry of the acoustic velocity field in the numeric experiments. Hydroacoustic leak-detection system for major gas pipelines is suggested based on the obtained results; it consists of the emitter and discrete receivers located along the UAC axis. The allocation precision is determined by the intervals between receiver along the UAC axis.

Application of fuzzy logic in optimization of continuous discrete control systems for multi-operational technological processes

Application of fuzzy logic in optimization of continuous discrete control systems for multi-operational technological processes

Semiglobal Nonmemoryless Attitude Controls on the Special Orthogonal Group

This paper presents tracking strategies for the attitude dynamics of a rigid body that are global on the configuration space SO(3) and semiglobal over the phase space SO(3)×ℝ3. It is well known that global attractivity is prohibited for continuous attitude control systems on the special orthogonal group. Such topological restriction has been dealt with either by constructing smooth attitude control systems that exclude a set of zero measure in the region of attraction or by introducing discontinuities in the control input. This paper proposes nonmemoryless attitude control systems that are continuous in time, where the region of attraction guaranteeing exponential convergence completely covers the special orthogonal group. This provides a new framework to address the topological restriction in attitude controls. The efficacy of the proposed methods is illustrated by numerical simulations and an experiment.

System for Continuous Analytical Control of Burden Materials for the Production of High-Quality Sinter

The capabilities of analytical control systems and their applicability in sinter production are considered. Industrial experiments showed that continuous control of the chemical composition of the components of sinter burden can improve the quality of sinter and save up to 8 kg of limestone and 1 kg of coke per ton of sinter produced.

Research, monitoring and diagnosis of continuous control systems IT capacity of information flows in of metallurgical enterprises

The article analyzes the effectiveness of the development, implementation and operation of information systems, IT infrastructures the system of metallurgical enterprises and government agencies. Identifying existing problems of the life cycle of IT systems. Some aspects of the development of information technology and the prospects for their use. Prospects of virtualization technologies with the existing development pattern element base processors. Developed IT strategy, which is the link between the strategy of development of the enterprise and the IT department. A comparative analysis of international experience in the application of foreign methodologies, ITIL, COBIT, offering tools to build systems that can provide solutions to highly targeted IT issues. Defined the scope of application of these methodologies in the development of information systems of national importance. A model of the efficiency of public services through information technology. We consider methodologies to gather in a single system the various methodologies, guidance, and legal aspects. The methods for evaluating the effectiveness of information systems. The analysis of simulation systems of information technologies in which they are applied.

Balance control systems in Parkinson's disease and the impact of pedunculopontine area stimulation.

Impaired balance is a major contributor to falls and diminished quality of life in Parkinson's disease, yet the pathophysiology is poorly understood. Here, we assessed if patients with Parkinson's disease and severe clinical balance impairment have deficits in the intermittent and continuous control systems proposed to maintain upright stance, and furthermore, whether such deficits are potentially reversible, with the experimental therapy of pedunculopontine nucleus deep brain stimulation. Two subject groups were assessed: (i) 13 patients with Parkinson's disease and severe clinical balance impairment, implanted with pedunculopontine nucleus deep brain stimulators; and (ii) 13 healthy control subjects. Patients were assessed in the OFF medication state and blinded to two conditions; off and on pedunculopontine nucleus stimulation. Postural sway data (deviations in centre of pressure) were collected during quiet stance using posturography. Intermittent control of sway was assessed by calculating the frequency of intermittent switching behaviour (discontinuities), derived using a wavelet-based transformation of the sway time series. Continuous control of sway was assessed with a proportional-integral-derivative (PID) controller model using ballistic reaction time as a measure of feedback delay. Clinical balance impairment was assessed using the 'pull test' to rate postural reflexes and by rating attempts to arise from sitting to standing. Patients with Parkinson's disease demonstrated reduced intermittent switching of postural sway compared with healthy controls. Patients also had abnormal feedback gains in postural sway according to the PID model. Pedunculopontine nucleus stimulation improved intermittent switching of postural sway, feedback gains in the PID model and clinical balance impairment. Clinical balance impairment correlated with intermittent switching of postural sway (rho = - 0.705, P < 0.001) and feedback gains in the PID model (rho = 0.619, P = 0.011). These results suggest that dysfunctional intermittent and continuous control systems may contribute to the pathophysiology of clinical balance impairment in Parkinson's disease. Clinical balance impairment and their related control system deficits are potentially reversible, as demonstrated by their improvement with pedunculopontine nucleus deep brain stimulation.

Investigation of the State of the Radiation Control Systems and the Actions of the Competent Authorities and the Population in the Event of a Change in the Radiation Background in Bulgaria

Abstract After the Chernobyl and Fukushima accidents, the monitoring of radiation at a real-time and timely publishing the information about the changes in order to inform the population has a major importance nowadays. In Bulgaria this system is working since 1997 to nowadays, and over the years it has been retrofitted twice. I made a research among 38 specialists in this field, 158 others trained to operate in a nuclear, chemical or other accident and 196 randomly selected representatives from the society. The results of my survey show the state of the radioactive background control systems and the knowledge about their working process by the specialists and also the population. The number of people that are familiar with the National Automated System for Continuous Control of the Radiochemical Background and the Radiation Population Disease Forecasting System in the Event of a Major Nuclear Accident of the National Institute of Meteorology and Hydrology is extremely low. The responses to the issues of coordination of the responsible authorities and agencies give us a real picture of the population's interest in the real situation of a radiation. The picture in the assessment of the coordination between the departments which announce the changing in the radiation situation on the territory of Bulgaria is similar. Most of the people who take part into the survey did not make suggestions on improving the situation, but on the other side there are also very reasonable and argumented ones. First of all, the participants indicate an increase in the population training about the real problem and conduction of such a regular and quality exercises

STPA for continuous controls: A flight testing study of aircraft crosswind takeoffs

A light aircraft crosswind takeoff is a risky operation. The purpose of this paper is to demonstrate the feasibility of applying STPA (Systems-Theoretic Process Analysis) to closed-loop continuous controls, identifying the hazards of crosswind takeoffs with light aircraft and the mitigating actions that could make its execution safer. The paper analyzes the variables that affect the response of the aircraft when subjected to severe crosswind, considering how aircraft characteristics affect its stability. The hazard analysis technique STPA is a tool based on the conceptual accident causality model called STAMP (System-Theoretic Accident Model and Processes), which in turn is based on systems theory. To deal with closed-loop actions on continuous control systems, a new approach to STPA was developed and effectively used to analyze data collected on a crosswind flight test campaign. This campaign, conducted by the Flight Test and Research Institute, led to a flight envelope extension of the Embraer’s training aircraft Super Tucano. The demonstration analysis showed the need for new, previously unidentified mitigating measures to be assigned to aircraft manufacturers, operators or owners, and their pilots.