scholarly journals Stability Analysis of Networked Control System Using LMI Approach

2018 ◽  
Vol 7 (2.31) ◽  
pp. 249
Author(s):  
Richa Sharma ◽  
Deepak Nagaria
Keyword(s):  
Communication Network ◽  
Control System ◽  
Closed Loop ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Linear Matrix ◽  
Matlab Simulation ◽  
Closed Loop System ◽  
The Stability

Networked control system is a closed loop system in which information or data travel through the communication network. The presence of communication network will increase time delay and information losses. Due to these losses and delay the performance of the system decreases. This paper represents an analysis to find the stability of the networked control system with the varying time hindrances present in the network. In this research, it has been assumed that the delay in time is less than the sampling period. The stability conditions for NCS have been procured with the use of the Lyapunov function approach and has been described in terms of LMI(Linear Matrix Inequality).This examination confirm the adequate state of stability through MATLAB simulation and the numerical case demonstrates the outcome.  

Design of Networked Control System with Time-Delay and Packet Loss

2014 ◽  
Vol 556-562 ◽  
pp. 5400-5403
Author(s):  
Lan Liu ◽  
Xun He Yin
Keyword(s):  
Control System ◽  
Time Delay ◽  
Packet Loss ◽  
Closed Loop ◽  
Random Network ◽  
Networked Control System ◽  
Networked Control ◽  
Linear Matrix ◽  
Controller Gain ◽  
System With Time Delay

For Networked Control System (NCS) with random network-induced delay and packet loss, an observer is designed to reconstruct the states using output values. A piece-wise time-delay strategy and the timestamp technique are used, improving the system performance. Depending on whether data dropout occurs or not, system is modeled as an Asynchronous Dynamical System (ADS), and theorem guaranteeing the system closed-loop stability is also given. Based on Lyapunov and Linear Matrix Inequality (LMI), controller gain and observer gain are solved and TrueTime toolbox is used to verify the effectiveness of the algorithm.

Research on Stability of Networked Control System with Uncertain Time-Varying Delays

2011 ◽  
Vol 383-390 ◽  
pp. 2138-2144
Author(s):  
Wei Hao Ma ◽  
Chao Yong Jin
Keyword(s):  
Control System ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Sufficient Condition ◽  
Time Varying ◽  
Matrix Inequalities ◽  
Time Varying Delay ◽  
Uncertain Time ◽  
Varying Delay

This note deals with the problem of stability for networked control system (NCS) with uncertain time-varying delay that is less than on sampling period. A new stability scheme was proposed. Using an Lyapunov function, less conservative stability sufficient condition was derived for such system based on liner matrix inequalities (LMs). Finally a numerical example shows the superiority of the method in this paper.

scholarly journals Improved Distributed Event-Triggered Control for Networked Control System under Random Cyberattacks via Bessel–Legendre Inequalities

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hongqian Lu ◽  
Chaoqun Guo ◽  
Yue Hu ◽  
Wuneng Zhou ◽  
Shihao Yan
Keyword(s):  
Control System ◽  
Stability Problem ◽  
Upper Bounds ◽  
Networked Control System ◽  
Networked Control ◽  
Numerical Examples ◽  
Network Transmission ◽  
Processing Delay ◽  
The Stability ◽  
Event Triggered

The stability problem of networked control system (NCS) with cyberattacks and processing delay is considered under an event-triggered scheme. An improved distributed event-triggered mechanism is proposed, which optimizes the performance of system dynamics and decreases the network transmission load simultaneously. By means of Bessel–Legendre inequality method and constructing an active Lyapunov–Krasovskii functional, a series of larger upper bounds of delay are obtained corresponding to the order of N. It is worth mentioning that the upper bound increases with N, which means that the conservatism of the stability criterion lowers. Finally, a distributed event-triggered controller is designed. The validity of the results is verified by numerical examples.

scholarly journals Robust LFC Strategy for Wind Integrated Time-Delay Power System Using EID Compensation

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3223 ◽  
Author(s):  
Liu ◽  
Zhang ◽  
Zou
Keyword(s):  
Time Delay ◽  
Power System ◽  
Closed Loop ◽  
Frequency Control ◽  
Loop System ◽  
Load Frequency Control ◽  
System Stability ◽  
Linear Matrix ◽  
Closed Loop System ◽  
The Stability

This paper presents an active disturbance rejection control (ADRC) technique for load frequency control of a wind integrated power system when communication delays are considered. To improve the stability of frequency control, equivalent input disturbances (EID) compensation is used to eliminate the influence of the load variation. In wind integrated power systems, two area controllers are designed to guarantee the stability of the overall closed-loop system. First, a simplified frequency response model of the wind integrated time-delay power system was established. Then the state-space model of the closed-loop system was built by employing state observers. The system stability conditions and controller parameters can be solved by some linear matrix inequalities (LMIs) forms. Finally, the case studies were tested using MATLAB/SIMULINK software and the simulation results show its robustness and effectiveness to maintain power-system stability.

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.

Smith Predictor Based on Predicting Induced-Delay

2011 ◽  
Vol 201-203 ◽  
pp. 2003-2006
Author(s):  
Shu De Li ◽  
Yi Chen ◽  
Cai Xia Liu
Keyword(s):  
Neural Network ◽  
Communication Network ◽  
Control System ◽  
Bp Neural Network ◽  
Networked Control System ◽  
Smith Predictor ◽  
Networked Control ◽  
Object Model ◽  
Random Delay

Since communication network is introduced into control system, induced-delay appears. Because of the delay, the performance of networked control system becomes bad, even unsteady. Conventional Smith predictor is sensitive to error in object model and needs delay’s value in advance. Regarding random delay, its application is limited. In this paper, we propose a method based on induced-delay predicted by BP neural network, which use two historical delay values to predict the next one. Smith predictor adjusts its parameters according to that value in time. The simulating results indicate that the precision of delay-predicting can be ensured and the performance of networked control system has been improved.

scholarly journals Joint Design of Control and Power Efficiency in Wireless Networked Control System

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Yan Wang ◽  
Zhicheng Ji
Keyword(s):  
Control System ◽  
Power Consumption ◽  
Adaptive Sampling ◽  
Power Efficiency ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
System Stability ◽  
Joint Design ◽  
Wireless Networked Control System

This paper presents a joint design method for wireless networked control system (WNCS) to balance both the demands of network service and the control performance. Since the problems of power consumption, communication reliability, and system stability exist simultaneously and interdependently in WNCS, most of the achieved results in the wireless network and wired networked control system cannot be used directly. To coordinate the three problems, sampling period is found to be the linking bridge. An adaptive sampling power efficiency algorithm is proposed to manage the power consumption such that it can meet the demands of network life span. The sampling period is designed to update periodically on the constraints of network schedulability and system stability. The convergence of the power efficiency algorithm is further proved. The sampling period is no longer a fixed value, however; thus, increasing the difficulty in modeling and controlling such a complicated time-varying system remains. In this work, a switched control system scheme is applied to model such a WNCS, and the effect of network-induced delay is considered. Switched feedback controllers are introduced to stabilize the WNCS, and some considerations on stability condition and the bounds of the update circle for renewing sampling period are discussed. A numerical example shows the effectiveness of the proposed method.

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