Perturbations in Networked Control Systems

2001 ◽  
Author(s):  
Octavian Beldiman ◽  
Linda G. Bushnell ◽  
Gregory C. Walsh ◽  
Hua O. Wang ◽  
Yiguang Hong
Keyword(s):  
Control System ◽  
Control Systems ◽  
Networked Control Systems ◽  
Networked Control System ◽  
Networked Control ◽  
Asymptotically Stable ◽  
Networked System ◽  
External Perturbations ◽  
Exponentially Stable

Abstract In this paper we study the effect of external perturbations on a networked control system. We start by assuming that the non-networked system without perturbation is exponentially stable. Then, for fast enough networks we show that if the perturbation is bounded the networked system is ultimately bounded and if the perturbation is vanishing then the networked system is asymptotically stable. We conclude the paper with simulations verifying the results.

scholarly journals The Design of Robust Controller for Networked Control System with Time Delay

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Zhongda Lu ◽  
Lijing Wang ◽  
Fengbin Zhang ◽  
Fengxia Xu
Keyword(s):  
Control System ◽  
Time Delay ◽  
Control Systems ◽  
Networked Control Systems ◽  
System Modeling ◽  
Networked Control System ◽  
Networked Control ◽  
Loop Model ◽  
The Stability ◽  
System With Time Delay

This paper considers the stability andH∞control problem of networked control systems with time delay. Taking into account the influence of network with delay, unknown input disturbance, and uncertainties of the system modeling, meanwhile we establish a precise, closed-loop model for networked control systems with time delay. By selecting a proper Lyapunov-Krasovskii function and using Lyapunov theorem, a sufficient condition for stability of the system in the form of LMI is demonstrated, corresponding controller parameters are acquired, and the convergence of the control algorithm is proved. The simulation example shows that the construction of the network robust control system with time delay indeed improves the stability performance of the system, which indicates the effectiveness of the design.

scholarly journals Stability and Time Delay Tolerance Analysis Approach for Networked Control Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ashraf F. Khalil ◽  
Jihong Wang
Keyword(s):  
Control System ◽  
Time Delay ◽  
Control Systems ◽  
Networked Control Systems ◽  
Networked Control System ◽  
Networked Control ◽  
Finite Difference Approximation ◽  
System Stability ◽  
Delay Tolerance ◽  
Maximum Time

Networked control system is a research area where the theory is behind practice. Closing the feedback loop through shared network induces time delay and some of the data could be lost. So the network induced time delay and data loss are inevitable in networked control Systems. The time delay may degrade the performance of control systems or even worse lead to system instability. Once the structure of a networked control system is confirmed, it is essential to identify the maximum time delay allowed for maintaining the system stability which, in turn, is also associated with the process of controller design. Some studies reported methods for estimating the maximum time delay allowed for maintaining system stability; however, most of the reported methods are normally overcomplicated for practical applications. A method based on the finite difference approximation is proposed in this paper for estimating the maximum time delay tolerance, which has a simple structure and is easy to apply.

scholarly journals A Comprehensive Review of the Evolution of Networked Control System Technology and Its Future Potentials

2021 ◽  
Vol 13 (5) ◽  
pp. 2962
Author(s):  
Mayank Kumar Gautam ◽  
Avadh Pati ◽  
Sunil Kumar Mishra ◽  
Bhargav Appasani ◽  
Ersan Kabalci ◽  
...  
Keyword(s):  
Control System ◽  
Control Systems ◽  
Communication Networks ◽  
Networked Control Systems ◽  
Networked Control System ◽  
Networked Control ◽  
Future Research ◽  
Feedback Signal ◽  
System Technology ◽  
Practical Applications

Networked control systems (NCSs) are attracting the attention of control system engineers. The NCS has created a paradigm shift in control system technology. An NCS consists of control loops joined through communication networks in which both the control signal and the feedback signal are exchanged between the system and the controller. However, its materialization faces several challenges as it requires the integration of advanced control and communication techniques. This paper presents an extensive review of NCSs from the perspective of control system design. The evolution of NCSs is broadly divided in three phases, namely NCSs prior to 2000, NCSs during 2001–2010, and NCSs from 2011 onwards. This division corresponds to the initial status, intermediate status, and the recent status of the developments in the design of NCSs. The advancement of different control techniques during these phases has been discussed comprehensively. This paper also describes the transition of control systems form continuous domain to networked domain, which makes it better than the traditional control systems. Some important practical applications, which have been implemented using NCSs, have also been discussed. The thrust areas for future research on NCS have also been identified.

scholarly journals Implementasi Networked Control System dalam Pengendalian Kecepatan Motor DC melalui Jaringan Komunikasi

2018 ◽  
Author(s):  
Asep Najmurrokhman
Keyword(s):  
Control System ◽  
Control Systems ◽  
Power Electronics ◽  
Networked Control Systems ◽  
Electrical Power ◽  
Networked Control System ◽  
Networked Control ◽  
Communication Control

Makalah ini telah dipresentasikan dalam The 6th Electrical Power, Electronics, Communication, Control, And Informatics Seminar; Universitas Brawijaya, 30-31 Mei 2012. Networked control systems (NCS) adalah sistem kendali yang melibatkan jaringan komunikasi sebagai bagian dari lingkar kendali. Makalah ini menguraikan tentang perancangan dan implementasi prototipe NCS berupa pengendalian kecepatan motor DC melalui jaringan publik. Dalam penelitian ini, sebuah motor DC dirancang harus mampu mengikuti setpoint yang dikirim melalui jaringan komunikasi. Sebuah pengendali tipe integral yang ditempatkan terpisah dengan plantnya dirancang agar motor DC memiliki kemampuan setpoint tracking tersebut. Konfigurasi eksperimen terdiri atas motor DC buatan Quanser, Akuisisi data menggunakan produk National Instruments (NI) yaitu seri DAQ PCI-6221 dan SCB-68, serta perangkat lunak LabVIEW sebagai antarmuka perangkat keras dan jaringan komunikasi. Hasil pengujian menunjukkan kemampuan setpoint tracking diperoleh melalui pengaturan nilai penguatan integral dari pengendalinya.

The Simulation Platform of Network Control System

2012 ◽  
Vol 562-564 ◽  
pp. 1434-1437
Author(s):  
Chen Liang ◽  
Jun Lin
Keyword(s):  
Control System ◽  
Control Systems ◽  
Networked Control Systems ◽  
Networked Control System ◽  
Network Control ◽  
Networked Control ◽  
Control Technique ◽  
Simulation Platform ◽  
Analysis And Design ◽  
Technology Control

With the development of electronic technology, computer and networked communication technology, control system is speeding up from close and centralized architecture to being open and distributed, to satisfy the continuous developing requirement of control quality and management. Networked control system is gradually formed in the process, and soon become one of the most important domains of control technique. One of the research of networked control systems is the effect of network upon control systems .A simulation platform of networked control systems is designed for this purpose. Matlab is used to build models of real systems. The simulation platform gives good environment for the analysis and design of networked control systems.

scholarly journals ISA 100.11a Networked Control System Based on Link Stability

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5417 ◽  
Author(s):  
Heitor Florencio ◽  
Adrião Dória Neto ◽  
Daniel Martins
Keyword(s):  
Control System ◽  
Control Systems ◽  
Wireless Network ◽  
Networked Control Systems ◽  
Networked Control System ◽  
Network Control ◽  
Networked Control ◽  
Control Loop ◽  
Link Stability ◽  
Tank System

Wireless networked control systems (WNCSs) must ensure that control systems are stable, robust and capable of minimizing the effects of disturbances. Due to the need for a stable and secure WNCS, critical wireless network variables must be taken into account in the design. As wireless networks are composed of several links, factors that indicate the performances of these links can be used to evaluate the communication system in the WNCS. This work presents a wireless network control system composed of ISA 100.11a sensors, a network manager, a controller and a wired actuator. The system controls the liquid level in the tank of the coupled tank system. In order to assess the influence of the sensor link failure on the control loop, the controller calculates the link stability and chooses an alternative link in case of instability in the current link. Preliminary tests of WNCS performance were performed to determine the minimum stability value of the link that generates an error in the control loop. Finally, the tests of the control system based on link stability obtained excellent results. Even with disturbances in the network links, the control system error remained below the threshold.

scholarly journals Stability Analysis of Networked Control Systems with Multi-Packet Dropout based on Switched System Approach

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Control System ◽  
Control Systems ◽  
Networked Control Systems ◽  
Lyapunov Stability Theory ◽  
Networked Control System ◽  
Switched System ◽  
Point Of View ◽  
Packet Transmission ◽  
Networked Control ◽  
Packet Dropout

Networked control system models with packet dropout in multi-packet transmission were established under hypothetical conditions in this paper, and the system was seen as a switched system. The causes of packet dropout in networked control system are analyzed in view of single-packet transmission and multi-packet transmission respectively. Based on Lyapunov stability theory, the property of the networked control system with multi-packet dropout was analyzed from the point of view of an asynchronous dynamic system. The method which determined the multi-packet dropout boundary to keep the system steady was given. The simulation results show the influences of multi-packet dropout on the system performance and prove the validity of the analytical method proposed in this paper.

scholarly journals Fault tolerance in networked control systems under intermittent observations

2011 ◽  
Vol 21 (4) ◽  
pp. 639-648 ◽  
Author(s):  
Jean-Philippe Georges ◽  
Didier Theilliol ◽  
Vincent Cocquempot ◽  
Jean-Christophe Ponsart ◽  
Christophe Aubrun
Keyword(s):  
Control System ◽  
Fault Tolerance ◽  
Control Systems ◽  
Networked Control Systems ◽  
Fault Tolerant ◽  
Networked Control System ◽  
Networked Control ◽  
Interacting Multiple Model ◽  
Multiple Model ◽  
Packet Losses

Fault tolerance in networked control systems under intermittent observationsThis paper presents an approach to fault tolerant control based on the sensor masking principle in the case of wireless networked control systems. With wireless transmission, packet losses act as sensor faults. In the presence of such faults, the faulty measurements corrupt directly the behaviour of closed-loop systems. Since the controller aims at cancelling the error between the measurement and its reference input, the real outputs will, in such a networked control system, deviate from the desired value and may drive the system to its physical limitations or even to instability. The proposed method facilitates fault compensation based on an interacting multiple model approach developed in the framework of channel errors or network congestion equivalent to multiple sensors failures. The interacting multiple model method involved in a networked control system provides simultaneously detection and isolation of on-line packet losses, and also performs a suitable state estimation. Based on particular knowledge of packet losses, sensor fault-tolerant controls are obtained by computing a new control law using fault-free estimation of the faulty element to avoid intermittent observations that might develop into failures and to minimize the effects on system performance and safety.

scholarly journals A real-time web-based networked control system education platform

2018 ◽  
Vol 55 (2) ◽  
pp. 130-141 ◽  
Author(s):  
João Cavalcanti ◽  
Luis FC Figueredo ◽  
João Y Ishihara ◽  
Mariana C Bernardes ◽  
Pedro HRQA Santana ◽  
...  
Keyword(s):  
Control System ◽  
Control Systems ◽  
Real Time ◽  
Communication Networks ◽  
Networked Control Systems ◽  
Low Cost ◽  
Networked Control System ◽  
Networked Control ◽  
Multiple Controller ◽  
Education Platform

Networked control systems have recently experienced a surge in fundamental theoretical results ignited by numerous advantages of introducing shared multipurpose communication networks in control systems. Regarding developments on the practical side, however, a networked control system is still wanting when it comes to experimental platforms suitable for research and educational purposes, which contributes to most of networked control system theory being validated by means of numerical examples and simulations. This paper addresses this issue by presenting a low-cost real-time networked control system platform, based on custom hardware and software solutions that can be readily explored with the sole use of a web browser connected to the Internet. The technical decisions made during development represent a fundamentally novel take on networked control system experimental platforms that can potentially be reproduced by several universities. The platform provides the user with multiple controller and input reference options, network configurations, delay statistics, and even a downloadable file containing advanced experiment data. A survey conducted with students located over 1200 km away from the platform who used it during laboratory assignments highlight the system’s usability and interactivity, and supports the platform is suitable for educational purposes.

scholarly journals NETWORKED CONTROL SYSTEMS: A PERSPECTIVE FROM CHAOS

2005 ◽  
Vol 15 (10) ◽  
pp. 3075-3101 ◽  
Author(s):  
GUOFENG ZHANG ◽  
TONGWEN CHEN
Keyword(s):  
Control System ◽  
Nonlinear System ◽  
Control Systems ◽  
Networked Control Systems ◽  
Initial Conditions ◽  
Transmission Rate ◽  
Signal Transmission ◽  
Networked Control System ◽  
Networked Control ◽  
Linear Feedback

In this paper, a nonlinear system aiming at reducing the signal transmission rate in a networked control system is constructed by adding nonlinear constraints to a linear feedback control system. Its stability is investigated in detail. It turns out that this nonlinear system exhibits very interesting dynamical behaviors: in addition to local stability, its trajectories may converge to a nonorigin equilibrium or be periodic or just be random. Furthermore it exhibits sensitive dependence on initial conditions — a sign of chaos. Complicated bifurcation phenomena are exhibited by this system. After that, control of the chaotic system is discussed. All these are studied under scalar cases in detail. Some difficulties involved in the study of this type of systems are analyzed. Finally an example is employed to reveal the effectiveness of the scheme in the framework of networked control systems.

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