Networked Control Systems Research Papers (original) (raw)

The present study deals with the analysis of a Lotka-Volterra model describing competition between tumor and immune cells. The model consists of differential equations with piecewise constant arguments and based on metamodel constructed by Stepanova. Using the method of reduction to discrete equations, it is obtained a system of difference equations from the system of differential equations. In order to get local and global stability conditions of the positive equilibrium point of the system, we use Schur-Cohn criterion and Lyapunov function that is constructed. Moreover, it is shown that periodic solutions occur as a consequence of Neimark-Sacker bifurcation.

- by
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- Functional Analysis, Algorithms, Networked Control Systems, Adaptive Control

It has never been accomplished to describe our behavior mathematically. Due to the fact that human behavior is highly erratic even the understanding of its causes are still sketchy. Assuming that we are all equal in our regulation of thought and behavior there are simply too many differences and partially inconsistencies, the attempts stopped in its onset. For having defined the five major groups of mankind, the sociopath, the artist, the median, the, and the psychopath［1］each group is related to each other but his decision making is hardwired differently and thou probably more easy to grasp than sticking to the consistency of all appearance for the regulation of behavior is quite similar in the five groups but different in its limits. Using the more formalistic tools of mathematics, this can open the review of the equations in verifying or falsifying the predictions on future behavior in an individual, at least after defining the group affiliation. Therefore a self-test has been established［2］to predetermine the group. In a hybrid-species ［3］, the eight main neuro-receptors in each group to have two optional origins. Measuring each by its own dominating patterns not only the amalgamation in each group can be defined but also the native patterns of the non-hybrid ancestry ［4］. Not only the variance of possible combination can distribute to the limits of brain-equations but also the time-axis of our memory, being rather different, illuminating the highly different decision making among offspring of hunters and farmers. A phenomenon probably explaining the variance in processing memory by peripheral distributed groups of ADHD and autism for ADHD memorizes in combining data with importance and such is been given an emotional response to the recall, while autism is mainly been given the exact time reference stored in a continuous frame of time-preference. The latter therefore have problems to distinguish between important and not important and the former lacks a passing timeframe, mirroring the primary form of acquiring resource, farming or hunting. With the boundaries set the graphs of the equation on resource-projection looks highly different by only changing its limits. Having not only focussed on the designation of human groups but also in behavioral shifts over time (from social to non-social) and the exact denomination of similar behavior, some rather simple equation could be defined to predict and consequently proof the predicate. Not only the proper use of words is necessary but also awareness that non-social individuals will often not answer truthfully. A topic that also can be mathematically predicted. The outcome will revolutionize our perception of mankind and ourselves, dawning more than one academic discipline, probably enabling us to go virtual and back again.

Networked Control System (NCS) has recently been a hotspot in the research fields of control theory
and control engineering application, where control system components (controller and controlled system or
plant) are connected via a shared network. Taking a third-order DC motor as the plant and using the TrueTime
toolbox in MATLAB, a NCS model is designed with Ethernet network as the communication channel. Through
the simulation, different traffic scenarios on Ethernet network are studied. Different load conditions induce
time-varying delays between measurements and control. To face these variations a delay-dependent gain
scheduling Proportional - Integral – Derivative (PID) controller has been designed.

Networked control systems are spatially distributed systems in which the communication between sensors, actuators, and controllers occurs through a shared band-limited digital communication network. Several advantages of the network architectures include reduced system wiring, plug and play devices, increased system agility, and ease of system diagnosis and maintenance. Consequently, networked control is the current trend for industrial automation and has ever-increasing applications in a wide range of areas, such as smart grids, manufacturing systems, process control, automobiles, automated highway systems, and unmanned aerial vehicles. The modelling, analysis, and control of networked control systems have received considerable attention in the last two decades. The ‘control over networks’ is one of the key research directions for networked control systems. This paper aims at presenting a survey of trends and techniques in networked control systems from the perspective of ‘control over networks’, providing a snapshot of five control issues: sampled-data control, quantization control, networked control, event-triggered control, and security control. Some challenging issues are suggested to direct the future research.

In software engineering, a design pattern is a general reusable solution to a commonly occurring problem within a
given context in software design. A design pattern is not a finished design that can be transformed directly into code.
It is a description or template for how to solve a problem that can be used in many different situations. Patterns are
formalized best practices that the programmer must implement themselves in the application. Object-oriented
design patterns typically show relationships and interactions between classes or objects, without specifying the final
application classes or objects that are involved. Many patterns imply object-orientation or more generally mutable
state, and so may not be as applicable in functional programming languages, in which data is immutable or treated as such.

The phenomenon of mixed-mode is one of the most important characteristics of switched delay systems. If a networked control system (NCS) with network induced delays and packet dropouts (NIDs & PDs) is recast as a switched delay system, it is imperative to consider the effects of mixed-modes in the stability analysis for an NCS. In this paper, with the help of the interpolatory quadrature formula and the average dwell time method, stabilization of NCSs using a mixed-mode based switched delay system method is investigated based on a novel constructed Lyapunov-Krasovskii functional. With the Finsler's lemma, new exponential stabilizability conditions with less conservativeness are given for the NCS. Finally, an illustrative example is provided to verify the effectiveness of the developed results.

This paper describes a dissipative controller design for networked control systems modeled by the Markovian jump system. Dissipativity refers to the existence of a supply rate dealing with the system such that the closed-loop system has a dissipative property. The main result of this paper is a solvability condition in terms of linear matrix inequalities for achieving dissipativity of a dynamic output feedback problem in networked control systems via the Markovian jump system approach. A numerical example is given to show the efficacy of the proposed design.

Efficiency and reliability have been essential requirements for energy generation in smart cities. This study presents the design and development of dependable control schemes for microgrid management, which can be seamlessly integrated into the management system of smart buildings. Here, to recover from failures in the solar energy system of a building microgrid, dependable controllers are proposed along with their hardware implementation. The system features the use of Internet of Things (IoT) as its core to coordinate the operation of multiple subsystems in a scalable manner. The control scheme uses a number of controllers cooperatively functioning via a token-based mechanism within the network to provide redundancy and thus reliability in solar tracking. The system exploits data from not only local in-situ sensors but also online sources via IoT networks for fault-tolerant control. Experiments conducted in a 12-storey building indicate that the harvested solar energy meets the design requirement while the control reliability is maintained in face of communication or hardware disruptions. The results confirmed the validity of the proposed approach and its applicability to energy management in smart buildings.

- by Manh Duong Phung
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- Networked Control Systems, Solar Energy, Smart Cities, Smart Buildings
- by Antonella Ferrara and +1
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- Networked Control Systems, Traffic control, Ramp Metering, Freeway Traffic Control

Control and Automation (IJITCA) is a Quarterly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Information Technology (IT), Control Systems and Automation Engineering. The journal focuses on all technical and practical aspects of IT, Control Systems and Automation with applications in real-world engineering and scientific problems. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on information technology, control engineering, automation, modeling concepts and establishing new collaborations in these areas. Authors are invited to contribute to this journal by submitting articles that illustrate research results, projects, surveying works and industrial experiences that describe significant advances in Information Technology, Control Systems and Automation.

Network control system (NCSs) are used for controlling remote plants via shared –band data communication networks. Due to some problems like communication time delay, data packet loss, network interference, signals jamming, it's difficult to achieve a satisfactory result when using the conventional control algorithm. In this paper, focusing on the above problems in Network Control Systems, a new kind of controller is designed that is the " Fuzzy PID " controller. When compared with conventional PID controller the dynamic performance of proposed " Fuzzy PID " controller is improved in terms of overshoot, settling time. This suggested design has been applied to control the speed of DC Servomotor as a remote plant using MATLAB SIMULATION. Thus the results shows that the designed controller used in this paper can increase the adaptability of the system and obtain a better control effect.

- by GRD JOURNALS
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- Fuzzy Logic, Networked Control Systems, Pid Controller, Smith Compensator

This paper reports on the empirical evaluation of five machine learning algorithm such as J48, BayesNet, OneR, NB and ZeroR using ten performance criteria: accuracy, precision, recall, F-Measure, incorrectly classified instances, kappa statistic, mean absolute error, root mean squared error, relative absolute error, root relative squared error. The aim of this paper is to find out which classifier is better in its performance for intrusion detection system. Machine Learning is one of the methods used in the intrusion detection system (IDS).Based on this study, it can be concluded that J48 decision tree is the most suitable associated algorithm than the other four algorithms. In this paper we compared the performance of Intrusion Detection System (IDS) Classifiers using seven feature reduction techniques.

In a network centric warfare environment, the commander may become the "weakest link" in the system of systems. With
increased number of sensors and network coverage, he will be overwhelmed with information that is beyond his cognitive
capacity to handle. This will impair his ability to make effective decision.
To alleviate information overload, we leverage the commander's cognitive limitation to design C2 systems differently to
present the right information and the right amount of information. The design will incorporate 3 aspects, viz., (a) intuitive
human-computer interactive interface to help the commander make sense of the voluminous information, (b) Decision support
tools to help him to make quality decision, (c) information processing to develop information to a form that is easily
understood by the commander. In this paper, we look at how cognitive science is applied in designing a real-time situation
awareness and planning system to facilitate quality decision making in real time.

- by See Chuan
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- Information Systems, Cognitive Science, Networked Control Systems, Cognitive Sciences

Applied Mathematics and Sciences: An International Journal (MathSJ ) aims to publish original research papers and survey articles on all areas of pure mathematics, theoretical applied mathematics, mathematical physics, theoretical mechanics, probability and mathematical statistics, and theoretical biology. All articles are fully refereed and are judged by their contribution to advancing the state of the science of mathematics.

We consider the implementation of simple process control applications through a CAN network. The goal of this paper is to study modifications on-line of controller parameters according to the global time delay in the control loop. Two methods that we use are the phase margin method and the dominant pole one. We evaluate the performances of the two methods in terms of the time response.

- by Xuan Hung NGUYEN
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- Networked Control Systems, QoS, QoC, Time Delay Compensation

This paper presents a distributed optimization scheme over a network of agents in the presence of cost uncertainties and over switching communication topologies. Inspired by recent advances in distributed convex optimization, we propose a distributed algorithm based on a dual sub-gradient averaging. The objective of this algorithm is to minimize a cost function cooperatively. Furthermore, the algorithm changes the weights on the communication links in the network to adapt to varying reliability of neighboring agents. A convergence rate analysis as a function of the underlying network topology is then presented, followed by simulation results for representative classes of sensor networks.

Abstract: this paper presents a framework to enable the analysis of the influence of the transmission faults on the reliability of a networked control system (NCS). The approach is composed of two parts: a modelling part in which all the basic components of a networked control system are modelled and a simulation part in which simulation is done on the models to evaluate the reliability. Due to external perturbations transmission faults may occur on the medium decreasing network quality of service and system performance. These aspects are difficult to assess with traditional dependability method like fault trees and reliability blocks. Our approach is applied to a case study example. The results show that our framework is an effective way for the reliability evaluation of networked control systems (Copyright IFAC 2008).

- by Rony Ghostine
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- Networked Control Systems, Reliability Analysis, Petri Net

Toeplitz Hermitian Positive Definite (THPD) matrices play an important role in signal processing and computer graphics and circular models, related to angular / periodic data, have vide applications in various walks of life. Visualizing a circular model through THPD matrix the required computations on THPD matrices using single bordering and double bordering are discussed. It can be seen that every tridiagonal THPD leads to Cardioid model.

A novel learning-based attack detection and estimation scheme is proposed for linear networked control systems (NCS), wherein the attacks on the communication network in the feedback loop are expected to increase network induced delays and packet losses, thus changing the physical system dynamics. First, the network traffic flow is modeled as a linear system with uncertain state matrix and an optimal Q-learning based control scheme over finite-horizon is utilized to stabilize the flow. Next, an adaptive observer is proposed to generate the detection residual, which is subsequently used to determine the onset of an attack when it exceeds a predefined threshold, followed by an estimation scheme for the signal injected by the attacker. A stochastic linear system after incorporating network-induced random delays and packet losses is considered as the uncertain physical system dynamics. The attack detection scheme at the physical system uses the magnitude of the state vector to detect attacks both on the sensor and the actuator. The maximum tolerable delay that the physical system can tolerate due to networked induced delays and packet losses is also derived. Simulations have been performed to demonstrate the effectiveness of the proposed schemes.

6th International Conference on Soft Computing, Mathematics and Control (SMC 2022) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications impacts and challenges of Soft Computing, Mathematics and Control. The conference documents practical and theoretical results which make a fundamental contribution for the development of Soft Computing, Mathematics and Control. The aim of the conference is to provide a platform to the researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the field.

The general objective of this paper is to provide a review and a qualitative comparison between two recent lines of research of observer-based non-centralized fault diagnosis techniques suited to be applied to distributed (interconnected) large-scale systems. The first line of research covered is based on unknown input observers to both decouple the effect of the interconnection among subsystems and to form a bank of observers to isolate faulty channels in a system. The second line of research analyzed is based on the use of observers with an adaptive approximation term designed to "learn" the interconnection function, which is the link that couples the dynamics from different subsystems.

Forced Van der Pol oscillator exhibits chaotic behaviour and instability under certain parameters and this poses a great threat to the systems where it has been applied hence, the need to develop a control method to stabilize and control chaos in a Forced Van der Pol oscillator so as to avoid damage in the controlled system and also to prevent unmodeled dynamics from being introduced in the system. Sliding Mode control makes use of the regulatory variables derived from the controlled Lyapunov function to bring the new variables to stability. The essence of using Integral Backstepping was to prevent chattering which can occur in the control input and can cause instability to the system by igniting unmodeled dynamics. Simulation was done using MATLAB and the results were provided to show the effectiveness of the proposed control method. Integral Backstepping Sliding Mode control method was effective towards stability and chaos control. It was also robust towards matched and unmatched disturbance.

—A Receding Horizon Control (RHC) strategy for nonlinear Networked Control Systems (NCS) described by polynomial models subject to input, state and communication constraints is presented. By resorting to a set-theoretic framework, sequences of pre-computed inner approximations of the one-step controllable sets are on-line exploited to compute the commands to be applied to the plant in a receding horizon fashion. The key aim is to present Sum-of-Squares (SOS) conditions under which the one-step controllable sets for nonlinear polynomial systems subject to time-delay phenomena on the transmitted signals can be off-line computed. Specifically, the communication channel effects are taken into account by considering Independent-of-Delay and Delay Dependent stability concepts that are used to initialize the one-step controllable sequences. Feasibility, asymp-totic closed-loop stability and constraints fulfilment regardless of any bounded time delay occurrences are formally proved. Finally, experimental results on a laboratory two-tank test-bed show the effectiveness of the proposed approach.

The Bearing-Only Target Motion Analysis (BOTMA) problem is to estimate the position and velocity of a
target using bearing measurements. In this paper, we assume that the observer can access the inequality constraints
imposed on target's speed, range, or target's course. For example, one constraint on a target's range is that it is upper
bounded by the maximum sensing range of the observer. We introduce an inequality constrained TMA, which is to
derive target states satisfying the constraints. We verify the effectiveness of our inequality constrained TMA using
MATLAB simulations.

Model predictive control (MPC) is an advanced control algorithm that has been very successful in the control industries due to its capability of handling multi input multi output (MIMO) systems with physical constraints. In MPC, the control action are obtained by solving a constrained optimization problem at every sample interval to minimize the difference between the predicted outputs and the reference value through the using of minimum control energy and satisfying the constraints of the physical system. Quadratic programing (QP) problem is solved using QPKWIK method which improves the active set method. The system architecture and design for the implementation of online MPC on the FPGA is taken into consideration in this paper to control a DC motor. This implementation is completed using Spartan6 Nexys3 FPGA chip using simulation environment (EDK tool) and the comparison between MPC and PID controller is also established.

The work proposed in this paper aims to design a robust stabilization of an underactuated quadrotor UAV system in presence of sensor failures. The dynamical model of quadrotor while taking into account various physical phenomena, which can influence the dynamics of a flying structure is presented. Subsequently, a new control strategy based on backstepping approach is developed. Lyapunov based stability analysis shows that the proposed control strategy design keep the stability of the closed loop dynamics of the quadrotor UAV even after the presence of sensor failures. Numerical simulation results are provided to show the good tracking performance of proposed control laws.

The paper addresses the stabilization problem for constrained control systems where both plant measurements and command signals in the loop are sent through communication channels subject to time-varying delays and data losses. A novel receding horizon strategy is proposed by resorting to an uncertain polytopic linear plant framework. Sequences of pre-computed inner approximations of the one-step controllable sets are on-line exploited as target sets for selecting the commands to be applied to the plant in a receding horizon fashion. The communication channel effects are taken into account by resorting to both Independent-of-Delay and Delay-Dependent stability concepts that are used to initialize the one-step controllable sequences. The resulting framework guarantees Uniformly Ultimate Boundedness and constraints fulfilment of the regulated trajectory regardless of plant uncertainties and data loss occurrences.

International Journal of Information Technology, Control and Automation (IJITCA) is a Quarterly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Information Technology (IT), Control Systems and Automation Engineering. The journal focuses on all technical and practical aspects of IT, Control Systems and Automation with applications in real-world engineering and scientific problems. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on information technology, control engineering, automation, modeling concepts and establishing new collaborations in these areas.

The present paper investigates the robustness of the directed cycle graph using the Nyquist criterion and derives the limit to which a single gain can be varied, while achieving positional consensus among the agents in heterogeneous cyclic pursuit framework. This work builds on similar robustness results for multi-agent systems connected by undi-rected graphs, in the literature. Simulations back up the theoretical results.

- by Dwaipayan Mukherjee and +1
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- Multiagent Systems, Networked Control Systems

In present scenario GPS is widely used to provide extremely accurate position information for navigation. From, where the GPS does not give continuous localization in environments where signal blockages are present, Inertial Navigation System comes into action. Because of sensors present in INS and time integration process, errors get accumulated over time. Henceforth, an aiding system is integrated with INS. The aim of this paper is to model VMS and RADAR and aid it with INS in order to overcome its errors. VMS is aided to INS to achieve acceptable accuracy and ease of implementation, much needed in civilian navigation. Different trajectories are generated to offer solutions in a practical scenario. Whereas, for highly accurate positioning in military navigation a reliable aiding system, Radar has been opted. The Kalman filter is designed and modeled as the integrating element in INS/RADAR, to provide an optimal estimate of navigation solutions. An error analysis has been done for both INS aided VMS and INS aided Radar systems. The navigation performance of VMS and Radar aiding system is compared and their merits have been brought out. We besides give the readers a more honest insight of the demand for an aiding system in different environments based on various simulation results.

Computer networks are a system of interconnected computers for the impetus of sharing the digital information among various networks. The concept of a networking began in 1962 when a server at the Massachusetts Institute of Technology (MIT) was connected to a server in Santa Monica, California for the purpose of communication between the two nodes. Since that time the proliferation of computers and computer networks has increased rapidly. One of the most significant challenges to networks is to prevent the attacks on their resources caused by inadequate network security which causes the malfunctioning of the system. The purpose of the project is establish a connection between the sectors of the networking domain. The project deals with the association of network in the enterprise and MNCs. Imagine a world with less interruption in the network functioning with the higher bandwidth usage. To support the better performance, resilience, security, maintainability and efficiency. Networking deals with the four layer of the OSI model. The purpose of the topology is to establish a seamless connection between the different routers and switches across the various geographical region.

- by IAEME Publication
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- Networked Control Systems

Macro-programming is the new generation advanced method of using Wireless Sensor Network (WSNs), where application developers can extract data from sensor nodes through a high level abstraction of the system. Instead of developing the entire application, task graph representation of the WSN model presents simplified approach of data collection. However, mapping of tasks onto sensor nodes highlights several problems in energy consumption and routing delay. In this paper, we present an efficient hybrid approach of task mapping for WSN – Hybrid Genetic Algorithm, considering multiple objectives of optimization – energy consumption, routing delay and soft real time requirement. We also present a method to configure the algorithm as per user's need by changing the heuristics used for optimization. The trade-off analysis between energy consumption and delivery delay was performed and simulation results are presented. The algorithm is applicable during macro-programming enabling developers to choose a better mapping according to their application requirements.

A model-based event-triggered control scheme for nonlinear constrained continuous-time uncertain systems in net-worked configuration is presented in this paper. It is based on the combined use of Model Predictive Control (MPC) and Integral Sliding Mode (ISM) control, and it is oriented to reduce the packets transmission over the network both in the direct path and in the feedback path, in order to avoid network congestion. The key elements of the proposed control scheme are the ISM local control law, the MPC remote controller, a smart sensor and a smart actuator, both containing a copy of the nominal model of the plant. The role of the ISM control law is to compensate matched uncertainties, without amplifying the unmatched ones. The MPC controller with tightened constraints generates the control component oriented to comply with state and control requirements , and is asynchronous since the underlying constrained optimization problem is solved only when a triggering event occurs. In the paper, the robustness properties of the controlled system are theoretically analyzed, proving the regional input-to-state practical stability of the overall control scheme.

- by Gian Paolo Incremona and +1
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- Model Predictive Control, Networked Control Systems, Sliding mode control

—We consider the problem of throughput-optimal packet dissemination, in the presence of an arbitrary mix of unicast, broadcast, multicast and anycast traffic, in a general wireless network. We propose an online dynamic policy, called Universal Max-Weight (UMW), which solves the above problem efficiently. To the best of our knowledge, UMW is the first throughput-optimal algorithm of such versatility in the context of generalized network flow problems. Conceptually, the UMW policy is derived by relaxing the precedence constraints associated with multi-hop routing, and then solving a min-cost routing and max-weight scheduling problem on a virtual network of queues. When specialized to the unicast setting, the UMW policy yields a throughput-optimal cycle-free routing and link scheduling policy. This is in contrast to the well-known throughput-optimal Back-Pressure (BP) policy which allows for packet cycling, resulting in excessive latency. Extensive simulation results show that the proposed UMW policy incurs a substantially smaller delay as compared to the BP policy. The proof of throughput-optimality of the UMW policy combines ideas from stochastic Lyapunov theory with a sample path argument from adversarial queueing theory and may be of independent theoretical interest.

Networked Control Systems (NCS) has been one of the main research areas in the last few years, due to the benefits of the insertion of a communication network in distributed systems, and the widely area of applications such as tele-operations, robotics, UAVs, power systems, among others, and new growing areas like smart grids and Cyber-Physiscal Systems. This paper surveys the main aspects on performance analysis and controllers design that take into account the problems that arise when the control feedback loop is closed over a communication network. At the end, an example of a NCS implementation using the simulation tool TrueTime is introduced, and some recent results and possible future directions are presented.

- by Jairo Giraldo and +1
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- Networked Control Systems
- by Xuan Nguyen
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- Networked Control Systems, Process Control, QoS, Quality of Service

Fighting wildfires is a precarious task, imperiling the lives of engaging firefighters and those who reside in the fire's path. Firefighters need online and dynamic observation of the firefront to anticipate a wildfire's unknown characteristics, such as size, scale, and propagation velocity, and to plan accordingly. In this paper, we propose a distributed control framework to coordinate a team of unmanned aerial vehicles (UAVs) for a human-centered active sensing of wildfires. We develop a dual-criterion objective function based on Kalman uncertainty residual propagation and weighted multi-agent consensus protocol, which enables the UAVs to actively infer the wildfire dynamics and parameters, track and monitor the fire transition, and safely manage human firefighters on the ground using acquired information. We evaluate our approach relative to prior work, showing significant improvements by reducing the environments cumulative uncertainty residual by more than 10 2 and 10 5 times in firefront coverage performance to support human-robot teaming for firefighting. We also demonstrate our method on physical robots in a mock firefighting exercise.

- by Esmaeil Seraj
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- Robotics, Networked Control Systems, Unmanned Aerial Vehicles, Multi-Agent Systems

Cinnamons are a new computation model intended to form a theoretical foundation for Control Network Programming (CNP). CNP has established itself as a programming approach combining declarative and imperative features. It supports powerful tools for control of the computation process; in particular, these tools allow easy, intuitive, visual development of heuristic, nondeterministic, or randomized solutions. The paper providesrigorous definitions of the syntax and semantics of the new model of computation, at the same time trying to keep the intuition behind clear. The purposely simplified theoretical model is then compared to both WHILE-programs (thus demonstrating its Turing completeness), and the "real" CNP. Finally, future research possibilities are mentioned that would eventually extend the cinnamon programming and its theoretical foundation into the directions of nondeterminism, randomness and fuzziness.

In this paper we present a novel receding horizon control scheme for solving the formation problem of leader-follower configurations. The algorithm is based on set-theoretic ideas and is tuned for agents described by linear time-invariant (LTI) systems subject to input and state constraints. Terminal robust positively invariant regions and sequences of pre-computed inner approximations of the one-step controllable sets are on-line exploited to compute the commands to be applied in a receding horizon fashion. Moreover, we prove that the design of both terminal sets and one-step ahead controllable regions is achieved in a distributed sense. Experiments are finally performed on a group of mobile robots to demonstrate the effectiveness of the proposed control strategy.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Abstract In this paper, we present a supervisory discrete-time predictive control strategy for load/frequency control problems in networked multi-area power systems subject to coordination constraints. Coordination between the control center and the spatially distributed areas is accomplished via data networks subject to communication latency modeled by time-varying time-delay. The aim here is finding supervising strategies able to reconfigure, whenever necessary in response to unexpected load changes and/or faults, the nominal set-points on frequency and generated power to the generators of each area so that viable evolutions would arise for the overall power system and a new sustainable equilibrium is reached. In order to demonstrate the effectiveness of the strategy, examples on a four-area power system are presented.

Motivated by the increasing interest in networked multi-agent systems and the wide number of applications in distributed control of smart grids, we address the problem of synchronization of microgrids. Two topologies are considered: the physical topology that relates the interconnection of distributed generators and loads, and the communication topology, which describes the information flow of the power system measurements. We propose a control strategy based on the information flow and we show that there exists a strong relationship between both topologies in order to achieve synchronization. As a matter of fact, we show that our results can be extended when isolated group of nodes are taken into account, and they can be connected or disconnected to the main grid. Finally, the effects of time-varying sampling are analyzed using some average passivity conditions, and sampling-time independence is demonstrated with the proposed controller.

- by Jairo Giraldo and +2
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- Networked Control Systems, Synchronization, Smart Grid

The insertion of communication network in the feedback adaptive control loops makes the analysis and design of networked control systems more and more complex. This paper addresses the stability problem of linear time-invariant adaptive networked control systems. Our approach is novel in that the knowledge of the exact values of all system parameters is not required. The case of state feedback is treated in which an upper bound on the norm of matrix A is required to be known. The priori knowledge of upper bound on norm A is not required in constructing the controller but it is required only to determine an upper bound on the transmission period h that guarantees the stability of the overall adaptive networked control system under an ideal transmission process, i.e. no transmission delay or packet dropout Rigorous mathematical proofs are established relies heavily on Lyapunov's stability criterion. Simulation results are given to illustrate the efficacy of our design approach.

International Journal of Control Theory and Computer Modelling (IJCTCM) is a Quarterly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Control Theory and Computer Modelling. The journal focuses on all technical and practical aspects of Control Theory and Computer Modelling. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced control engineering and modeling concepts and establishing new collaborations in these areas

In this paper, we made a survey on Word Sense Disambiguation (WSD). Near about in all major languages around the world, research in WSD has been conducted upto different extents. In this paper, we have gone through a survey regarding the different approaches adopted in different research works, the State of the Art in the performance in this domain, recent works in different Indian languages and finally a survey in Bengali language. We have made a survey on different competitions in this field and the bench mark results, obtained from those competitions.