Control Theory Research Articles

PATENT ANALYSIS OF EXOSKELETON MECHANISMS AND WAY TO IMPROVE THEIR COMFORT. Continuation*

The issue of creating robotic anthropomorphic mechanisms called exoskeletons for humans is relevant. The exoskeleton design became practically possible due to technological developments, creating powerful computers, sensors, and detectors, collecting info about human movements, and advances in control theory. Introduction of available achievements in the domain of exoskeleton engineering and design, as well as exoskeleton parts and their control methods, protected by patents, to a general audience is the objective of the article. The research methods are analysis of patents and scientific publications on the topic of exoskeletons, and graphical processing of research results. The result of the conducted research is the survey of the patented exoskeletons available in the scientific world. It has been found that the available exoskeleton models are still not user-friendly enough. Therefore, the authors of the article developed and patented a model of an exoskeleton with variable-length links. The model of practical implementation of variable-length link based on using magneto-rheological fluid and adjusting the link stiffness by applying an external magnetic field has been proposed. The proposed model augments the exoskeleton user experience. It has been found that intense publication growth in scientific journals on researched topics started after 2011. The number of published exoskeleton patents increased almost tenfold in the past ten years by 2021. All these demonstrate significant interest in exoskeletons design.

A new method for the approximation of certain non-linear systems

Abstract A common problem in systems and control theory is to provide an approximation to non-linear systems. We provide a novel approach as a general solution to this problem originally conceived by Gamkrelidze. We consider and solve a general approximation problem which provides the fundamentals for various switching-type systems thus encompassing a wide range of systems theory problems.

Electrophysiological correlation between executive vigilance and attention network based on cognitive resource control theory

Attention is comprised of three independent and interacting attention networks: phasic alertness, orienting, and executive control. Previous studies have explored event-related potentials associated with these attention networks and executive vigilance, there is a lack of research on the relationship between executive vigilance and the three attention networks. However, there is a lack of research on the relationship between executive vigilance and the three attention networks. The present study aims to investigate this relationship. Based on the theory of cognitive resource control, two experimental blocks were designed with the vigilance task as the control variable. A total of 39 participants completed both ANTI and ANTI-V trials (two variants of the traditional attention network test ANT) in the same period. Through analysis of behavior measures (RT) and electrophysiological results related to phasic alertness (N1, P2, and contingent negative variation), orienting (P1, N1, and P3), and executive control (N2 and slow positive potential), we found that the reaction time of the ANTI block was lower than that of the ANTI-V block under all conditions, This suggests that adding a vigilance task may lead to reduced allocation of attention resources across all three attention networks. Furthermore, the orienting ability was weaker in the ANTI-V experimental block compared to that in the ANTI block due to effects on P1 and P3 regulation by the vigilance task. The N2 amplitude of the ANTI-V block was consistently reduced under similar conditions, indicating a weakening of executive control ability. The electrophysiological results revealed that executive vigilance inhibited the component of early attention perception related to the orienting network and was also related to the ability to detect conflict in the executive control network.

Three-dimensional line-of-sight-angle-constrained leader-following cooperative interception guidance law with prespecified impact time

To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight (LOS) angles in Three-Dimensional (3D) space, this paper proposes a 3D leader-following cooperative interception guidance law. First, in the LOS direction of the leader, an impact time-controlled guidance law is derived based on the fixed-time stability theory, which enables the leader to complete the interception task at a prespecified impact time. Next, in the LOS direction of the followers, by introducing a time consensus tracking error function, a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the time-to-go. Then, in the direction normal to the LOS, by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control (SMC) theory, an innovative 3D LOS-angle-constrained interception guidance law is developed, which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy consumption. Moreover, it effectively suppresses the chattering phenomenon while avoiding the singularity issue, and compensates for unknown interference caused by target maneuvering online, making it convenient for practical engineering applications. Finally, theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness, superiority, and robustness of the investigated guidance law.

In silico validation of a customizable fully-autonomous artificial pancreas with coordinated insulin, glucagon and rescue carbohydrates

Artificial pancreas systems should be designed considering different patient profiles, which is challenging from a control theory perspective. In this paper, a flexible-hybrid dual-hormone control algorithm for an artificial pancreas is proposed. The algorithm handles announced/unannounced meals by means of a non-interacting feedforward scheme that safely incorporates prandial boluses. Also, a coordination strategy is employed to distribute the counter-regulatory actions, which can be delivered as a continuous glucagon infusion via an automated pump, as an oral rescue carbohydrate recommendation, or as a rescue glucagon dose recommendation to be administrated through a glucagon pen. The different configurations of the proposed controller were evaluated in silico using a 14-day virtual scenario with random meal intakes and exercise sessions, achieving above 80% time-in-range and low time spent in hypoglycemia.

Research of integrated spiral maneuvering and guidance based on virtual target

To address the issue of interception, maneuvering, and precise guidance during the final stage of gliding flight, a study was conducted on the design of integrated maneuvering and guidance using a spiral trajectory as the focus. Firstly, the spiral trajectory was decomposed into an optimal reference trajectory considering the glide angle constraint and a relative motion trajectory. Then, virtual circular moving targets were introduced to meet the requirements of spiral maneuvering and virtual trajectory moving targets were introduced to ensure trajectory convergence, based on the task division of different flight stages. Finally, the guidance rate of the reference trajectory was designed based on optimal control theory, and the guidance rate of the spiral maneuver was designed based on pure proportional guidance. Simulation results show that this guidance method can enable the vehicle to perform active spiral maneuvers, and control the landing deviation and impact angle deviation to within 2.5 m and 1 degree, respectively.

Preface

Abstract In order to bring in the latest progress in theory, technology and application in the fields of electrical engineering and information technology at home and abroad in recent years, and show the latest research achievements, 2024 3rd International Conference on Electrical, Control and Information Technology (ECITech 2024) was held from January 19th to 21st, 2024 in Xiamen, China via virtual form. It was attended by about 120 participants from different countries and regions. At this conference we had a comprehensive overview of this fascinating field and of future scenarios thanks to the participation of distinguished delegates around the globe, including Prof. Hamid Reza Karimi (Politecnico di Milano, Italy), Prof. Mouquan Shen (Nanjing Tech University, China), Assoc. Prof. Jamaludin Jalani (Universiti Tun Hussein Onn Malaysia, Malaysia), and Assoc. Prof. Wenfeng Hu (Central South University, China). The experts performed wonderful keynote speeches, and the participants raised questions based on the speeches and interacted with the speakers and people around, leading to a heated discussion on the latest research findings and trends in related fields. As one of the important outcomes of ECITech 2024, this proceedings contains excellent academic contributions from all over the world, demonstrating the latest research results and innovative ideas in this field. These papers not only cover theoretical explorations of electrical, control and information technology, but also numerous practical application cases, which provide us with valuable experiences and insights. In this collection of papers, the authors, with profound academic background and keen insight, have discussed the hot issues in the field of electrical, control and information technology in depth. They have systematically analyzed and elaborated on the latest advances in electrical engineering, innovative applications of control theory, and the integration and development of information technology from different perspectives and at different levels. These papers not only enrich our understanding of the field, but also provide new ideas and directions for future research. We would like to thank all the experts, scholars and authors who participated in this conference for their hard work and excellent contributions, which made this conference a complete success and the publication of the proceedings. At the same time, we would also like to thank all the guests and attendees, whose enthusiastic participation and active support have made this conference a real academic feast. Finally, we sincerely hope that this proceedings will bring inspiration and harvest to the readers, and we also look forward to exploring more mysteries and possibilities in the field of electrical, control and information technology with you in the future academic exchanges and cooperation. The Committee of ECITech 2024 List of Committee Member is available in this Pdf.

A control theoretic analysis of oscillator Ising machines

This work advances the understanding of oscillator Ising machines (OIMs) as a nonlinear dynamic system for solving computationally hard problems. Specifically, we classify the infinite number of all possible equilibrium points of an OIM, including non-0/π ones, into three types based on their structural stability properties. We then employ the stability analysis techniques from control theory to analyze the stability property of all possible equilibrium points and obtain the necessary and sufficient condition for their stability. As a result of these analytical results, we establish, for the first time, the threshold of the binarization in terms of the coupling strength and strength of the second harmonic signal. Furthermore, we provide an estimate of the domain of attraction of each asymptotically stable equilibrium point by employing the Lyapunov stability theory. Finally, we illustrate our theoretical conclusions by numerical simulation.

LQR controller design for portable power supply based on flyback converter

Abstract The stability of the power repair equipment guarantees the reliability of the repair of electrical equipment. The following problems exist in the power supply of the emergency equipment: the load equipment randomly cuts in the power supply network; load equipment requires fast dynamic performance of the power supply. This challenges the stability of the portable power supply with the Flyback converter as the core. In this paper, an optimal feedback control strategy based on linear quadratic regulator (LQR) theory is proposed to improve the dynamic and steady-state performance of the Flyback converter. First, the state-averaged space model of the Flyback is derived and established. Second, an output voltage feedback integral controller is introduced to eliminate the steady-state error of the output voltage. Next, according to the LQR optimal control theory, the control model of the Flyback converter has been established, and the parameter design of the controller has been carried out by obtaining the optimal feedback gain matrix of the system. Finally, the simulation models are implemented with an output power of 120 W and a switching frequency of 50 kHz. The simulation results prove that the LQR controller provides superior performance than the traditional PI controller.

Dynamical Behaviors and Abundant New Soliton Solutions of Two Nonlinear PDEs via an Efficient Expansion Method in Industrial Engineering

In this study, we discuss the dynamical behaviors and extract new interesting wave soliton solutions of the two significant well-known nonlinear partial differential equations (NPDEs), namely, the Korteweg–de Vries equation (KdVE) and the Jaulent–Miodek hierarchy equation (JMHE). This investigation has applications in pattern recognition, fluid dynamics, neural networks, mechanical systems, ecological systems, control theory, economic systems, bifurcation analysis, and chaotic phenomena. In addition, bifurcation analysis and the chaotic behavior of the KdVE and JMHE are the main issues of the present research. As a result, in this study, we obtain very effective advanced exact traveling wave solutions with the aid of the proposed mathematical method, and the solutions involve rational functions, hyperbolic functions, and trigonometric functions that play a vital role in illustrating and developing the models involving the KdVE and the JMHE. These new exact wave solutions lead to utilizing real problems and give an advanced explanation of our mentioned mathematical models that we did not yet have. Some of the attained solutions of the two equations are graphically displayed with 3D, 2D, and contour panels of different shapes, like periodic, singular periodic, kink, anti-kink, bell, anti-bell, soliton, and singular soliton wave solutions. The solutions obtained in this study of our considered equations can lead to the acceptance of our proposed method, effectively utilized to investigate the solutions for the mathematical models of various important complex problems in natural science and engineering.

Применение принципа Понтрягина для оптимального отключения энергетического ядерного реактора

The theory of optimal control is based on two approaches, the dynamic programming method (Bellman equation) and Pontryagin maximum principle. Pontryagin maximum principle is applied in the physics of nuclear reactors when optimizing various transient processes. The mathematical justification of this theory is based on the elements of convex analysis, which is not used by physicists and engineers, so the physical issues are less studied in scientific literature. The subject of the study is a nuclear power reactor of the WWER type. The problem of minimizing its shutdown time, bypassing the iodine pit is solved and it is possible to start up the reactor at any moment after its shutdown. Analytical and numerical methods are used. The paper considers an example of applying the maximum principle for optimal control of the process of shutting down a nuclear reactor bypassing the iodine pit. A physical mathematical model of the Pontryagin principle is formulated. The process of optimal control of reactor shutdown for large and small reactivity margins is justified and calculated. Pontryagin principle does not contain an algorithm to find an optimization process; the stages of the process must be selected based on physical considerations, but these stages must satisfy the specified principle. Based on the Pontryagin principle, the results of the study make it possible to draw up a step-by-step action plan when shutting down a WWER-type reactor with any value of the reactivity margin and its switching is possible at any time after the transition process, which avoids downtime. The proposed plan can be used both in mathematical modeling of transient processes in a reactor and in reactor control systems to improve its controllability and, consequently, to improve safety.

SUSTAINABLE COVID-19 CONTROL MEASURES: A MATHEMATICAL MODELLING STUDY

Mathematical modelling techniques have become essential in predicting the consequences of viral disease outbreaks and in planning sustainable preventative measures to curb their transmission dynamics. To better understand the sustainable evolution of the control measures’ impacts on COVID-19 transmissions, a reaction-diffusion system is employed to describe the epidemiological phenomenon through two processes: (i) A reaction process of SEIRS-type (Susceptible, Exposed, Infected, Recovered, and Susceptible) kinetics; and (ii) a diffusion process that models local dispersal of individuals through the incorporation of spatial dimension. Optimal control theory and numerical simulation studies are performed to examine the combined effects of reinfection, spatial dispersal process, and distinct control measures on the severity of the outbreaks. The results indicate the effectiveness of implementing adequate control measures vaccination and treatments to prevent further disease outbreaks and minimise the number of infected cases. The insights from these modelling studies benefit different stakeholders, e.g., public health practitioners and policymakers in devising sustainable COVID-19 management plans to prepare for endemicity and deal with large-scale disease outbreaks in the future.

Parametric Correlation Analysis between Equivalent Electric Circuit Model and Mechanistic Model Interpretation for Battery Internal Aging

In modern electric vehicle applications, understanding the evolution of the internal electrochemical reaction throughout the aging of batteries is as relevant as knowing their state of health. This article demonstrates the feasibility of correlating a mechanistic model of the battery internal electrochemical reactions with an equivalent electrical circuit (EEC) model, providing a practical and understandable interpretation of the internal reactions for electrical specialists. By way of electrochemical impedance spectroscopy analysis and automatic control theory, a methodology for correlating the resistance and capacitance variations of the EEC model and how they reflect the electrochemical reaction changes is proposed. These changes are represented through the time constants of the three RC parallel arrays from an EEC model. PS-260 lead–acid batteries were analyzed throughout the SOC and their useful life to validate this methodology. The result analysis allows us to establish that the first RC array corresponds to the negative electrode reactions in the range of 1.48 Hz to 10 kHz, the second RC array to the positive electrode reactions and generation of sulfates in the range of 0.5 to 1.48 Hz, and the third RC array to the generation of sulfates and their diffusion in the range of 0.01 to 0.5 Hz.

Multi-Agent System Based Cooperative Control for Speed Convergence of Virtually Coupled Train Formation.

This paper investigates the problem of spacing control between adjacent trains in train formation and proposes a distributed train-formation speed-convergence cooperative-control algorithm based on barrier Lyapunov function. Considering practical limitations such as communication distance and bandwidth constraints during operation, not all trains can directly communicate with the leader and obtain the expected trajectory it sends, making it difficult to maintain formation consistency as per the predetermined ideal state. Furthermore, to address the challenge of unknown external disturbances encountered by trains during operation, this paper designs a distributed observer deployed on each train in the formation. This observer can estimate and dynamically compensate for unknown reference trajectories and disturbances solely based on the states of adjacent trains. Additionally, to ensure that the spacing between adjacent trains remains within a predefined range, a safety hard constraint, this paper encodes the spacing hard constraint using barrier Lyapunov function. By integrating nonlinear adaptive control theory to handle model parameter uncertainties, a barrier Lyapunov function-based adaptive control method is proposed, which enables all trains to track the reference trajectory while ensuring that the spacing between them remains within the preset interval, therefore guaranteeing the asymptotic stability of the closed-loop system. Finally, a practical example using data from the Guangzhou Metro Line 22, specifically the route from Shiguang Road Station to Chentougang Station over three stations and two sections, is utilized to validate the effectiveness and robustness of the proposed algorithm.

Navigating Hybrid Governance

The governing balance between civilian regime and military leadership has become an important aspect of governance in Pakistan. When military and civilian life are pragmatically in touch with each other, both become an asset, otherwise, they are an aggressor to each other. It is their integration that ensures the convergence of their goals and directions as well as values and ideologies, as both depend on each other. This not only leads to the consolidation of democracy but also fulfills the effective civilian oversight over the military. For this, an efficient governing structure can keep in check the state’s civil-military equation and ensure that the incidence of military intervention or influence is minimized. The theoretical and structural construction of this integration and ideological alignment is particularly relevant to civil-military interaction under the National Security Committee (NSC) in Pakistan. This paper analyzes the civil-military relations in Pakistan under two different models i.e., ‘control theory’ and ‘convergence theory’ to bring a new perspective to the analysis of the topic. The paper begins with a brief review of both theoretical frameworks, followed by the history of civil-military relations under military rule, civilian setup, and NSC governance in Pakistan. The paper then looks into the case of hybrid governance under the NSC in line with the tenets of the 1973 Constitution of Pakistan. It suggests that far-reaching national strategic concerns and governing balance issues can be addressed under NSC, which is currently not being utilized to its full potential; instead it should function as a regular forum of dialogue and consultation, and not as an irregular decision-making entity. A consistently functional consultative NSC can help diffuse the ideological differences between civil and military elements of governance, creating more prospects of integration and decreasing chances of outright interference , as postulated by Janowitz in the convergence theory.

Application of two-step input to reduce overshoot of the transient response at automated control systems

The problems of quality improving for technology control are very important and are considered in works on the theory of automatic control and related fields. Various approaches to solving the problems are known especially by the decreasing overshoot of step response. To provide this the most of existing methods require: to adjust a controller parameters; development of a mathematical model of a controlled object; additional filters applications, that as a whole is difficult to implement under industrial conditions. The authors have proposed another approach to solving the above problems, contrary to the known ones. Namely, to apply two successive inputs with lower amplitudes and delay in time instead of the known one step input. The response of the controlled system on the complex two step inputs was considered and the optimal time delay was defined. The investigations were conducted by the modelling a typical classic linear automation control system that consists of a static control object of the first order with time delay, proposal - integration - difference controllers. The modelling results for a transient under the various applied one and two step inputs, including their ramp variation were obtained. It was shown that the two-step inputs with their ramp application gives the decreasing of the maximum displacement for a transient in a typical control system: more than 3 times increase was shown comparing with the one-step approach. The optimal time interval between the steps was determined that leads to the maximum effectiveness of the technology application. The procedure to define the details of the approach application was developed

Development path of digital cultural industry by integrating proportional integral and differential algorithm from the perspective of cultural innovation

The digital culture business benefits from quick technical updates, digital manufacturing, communication networks, and customized consumption, which promotes new supply and consumption. The innovation and development of the digital cultural industry cannot be separated from the physical industry. The efficient production of the physical industry can ensure the innovative development of digital cultural industry. Therefore, to improve the production efficiency of physical industry, this research proposes a temperature control model combining whale optimization algorithm and fuzzy proportional integral differential algorithm based on the traditional temperature control in ceramic firing and wine making process. Firstly, fuzzy control theory is used to improve the proportional integral differential algorithm, and a fuzzy proportional integral differential model with adaptive adjustment function is established. On this basis, to quickly confirm the optimal parameters of the proportional integral differential model, the whale optimization algorithm is introduced to further optimize its weight factors. It was verified that the temperature control adjustment model combining whale optimization algorithm and fuzzy proportional integral differential model was 2.77 s, which was shortened by 1.11 s, 2.37 s and 3.13 s, respectively than the other three models. Therefore, the constructed temperature control model can effectively realize high-precision intelligent temperature control in industrial production, laying the cornerstone for promoting the innovative development of digital culture industry. The proposed model can improve the production efficiency of physical industries, promote digital transformation, and optimize the innovative development of digital cultural industries.

A Digital Twin Infrastructure for NGC of ROV during Inspection

Remotely operated vehicles (ROVs) provide practical solutions for a wide range of activities in a particularly challenging domain, despite their dependence on support ships and operators. Recent advancements in AI, machine learning, predictive analytics, control theories, and sensor technologies offer opportunities to make ROVs (semi) autonomous in their operations and to remotely test and monitor their dynamics. This study moves towards that goal by formulating a complete navigation, guidance, and control (NGC) system for a six DoF BlueROV2, offering a solution to the current challenges in the field of marine robotics, particularly in the areas of power supply, communication, stability, operational autonomy, localization, and trajectory planning. The vehicle can operate (semi) autonomously, relying on a sensor acoustic USBL localization system, tethered communication with the surface vessel for power, and a line of sight (LOS) guidance system. This strategy transforms the path control problem into a heading control problem, aligning the vehicle’s movement with a dynamically calculated reference point along the desired path. The control system uses PID controllers implemented in the navigator flight controller board. Additionally, an infrastructure has been developed that synchronizes and communicates between the real ROV and its digital twin within the Unity environment. The digital twin acts as a visual representation of the ROV’s movements and considers hydrodynamic behaviors. This approach combines the physical properties of the ROV with the advanced simulation and analysis capabilities of its digital counterpart. All findings were validated at the Point Rouge port located in Marseille and at the port of Ancona. The NGC implemented has proven positive vehicle stability and trajectory tracking in time despite external interferences. Additionally, the digital part has proven to be a reliable infrastructure for a future bidirectional communication system.

Application of locally regularized extremal shift to the problem of realization of a prescribed motion

Abstract A controlled system of differential equations under the action of an unknown disturbance is considered. The problem discussed in the paper consists in constructing algorithms for forming a control that provides the realization of a prescribed motion for any admissible disturbance. Namely these algorithms should provide the closeness in the metric of the space of differentiable functions of a phase trajectory of a given controlled system and some etalon trajectory of an analogous system functioning when any outer actions are absent. As the space of admissible disturbances, we take the space of measurable square integrable (with respect to the Euclidean norm) functions. The cases of inaccurate measurements of phase trajectories of both systems at all times and at discrete times are under study. Two computer oriented algorithms for solving the problem are designed. The algorithms are based on the (well-known in the theory of guaranteed control) method of extremal shift. In the process, its local (at each time of control correction) regularization is performed by the method of smoothing functional (the Tikhonov method). In addition, estimates for algorithm’s convergence rate are presented.

Quantum Brain Dynamics and Virtual Reality

In this paper we propose a control theory of manipulating holograms in Quantum Brain Dynamics (QBD) involving our subjective experiences, i.e. qualia. We begin with the Lagrangian density in QBD and extend our theory to a hierarchical model involving multiple layers covering the neocortex. We adopt reservoir computing approach or morphological computation to manipulate waveforms of holograms involving our subjective experiences. Numerical simulations performed indicate that the convergence to target waveforms of holograms is realized by external electric fields in QBD in a hierarchy. Our theory can be applied to non-invasive neuronal stimulation of the neocortex and adopted to check whether or not our brain adopts the language of holography. In case the protocol in a brain is discovered and the brain adopts the language of holography, our control theory will be applied to develop virtual reality devices by which our subjective experiences provided by the five senses in the form of qualia are manipulated non-invasively. Then, the information content of qualia might be directly transmitted into our brain without passing through sensory organs.