scholarly journals Design of Multi-Rate Multi-Zone Wireless Fuzzy Temperature Control System for Greenhouse Application

2020 ◽  
Vol 26 (7) ◽  
pp. 97-114
Author(s):  
Qays Jebur Sabr
Keyword(s):  
Control System ◽  
Fuzzy Controller ◽  
Networked Control Systems ◽  
Sampling Rate ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Temperature Control System ◽  
Temperature Controller ◽  
Input Gain

sensor sampling rate (SSR) may be an effective and crucial field in networked control systems.  Changing sensor sampling period after designing the networked control system is a critical matter for the stability of the system. In this article, a wireless networked control system with multi-rate sensor sampling is proposed to control the temperature of a multi-zone greenhouse. Here, a behavior based Mamdany fuzzy system is used in three approaches, first is to design the fuzzy temperature controller, second is to design a fuzzy gain selector and third is to design a fuzzy error handler. The main approach of the control system design is to control the input gain of the fuzzy temperature controller depending on the current zone and current sensor rate for each zone. Due to the low input gain of the fuzzy controller, the steady state output error of the greenhouse temperature is in the range (0.55 – 11.22) % when the system using five sensors of different sampling rates and in the range (2.43 - 16.74) % when the system using five sensors with the same sampling rates. Next, after designing the fuzzy error handler, this error doesn’t exceed 1.6%, but in most cases it is less than 0.15%.The work is Simulink designed and implemented using Matlab R2012b. The Zigbee wireless network is proposed for the system, it is implemented in Matlab using True time 2.0 library.

Modeling and Stability Analysis of Multi-Rate Networked Control Systems with Multiple Control Loops

2010 ◽  
Vol 139-141 ◽  
pp. 1827-1833 ◽  
Author(s):  
Dian Ting Liu ◽  
De Jian Zhou ◽  
Yao Ming Liu
Keyword(s):  
Control System ◽  
Networked Control Systems ◽  
Sampling Period ◽  
Networked Control System ◽  
Network Control ◽  
Networked Control ◽  
Control Loop ◽  
Multiple Control ◽  
Control Loops ◽  
Analysis And Design

A kind of multi-input and multi-output network control system with multiple independent control loops is examined in this paper. The controller of each control loop is connected with the sensor and actuator by a network and each control loop has a different sampling period. The whole mathematical model of this kind of networked control system is set up when the maximum network-induced delay is smaller than one sampling period. And the sufficient condition subject to the asymptotic stability of this kind of networked control system is derived based on the theorem for estimation of feature value deduced from perturbation theory. The research results of this paper have significance in the analysis and design of this kind of networked control system or a similar networked control system.

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.

Modeling and Simulation of Nonlinear Networked Control System Based on Fuzzy Control

2012 ◽  
Vol 426 ◽  
pp. 368-371
Author(s):  
Sheng Li Song ◽  
Y. Chen ◽  
S.J. Huang ◽  
L.H Yang ◽  
R. He
Keyword(s):  
Control System ◽  
Nonlinear Problem ◽  
Control Method ◽  
Fuzzy Controller ◽  
Good Control ◽  
Networked Control System ◽  
Networked Control ◽  
Packet Dropout ◽  
Data Packet Dropout ◽  
Nonlinear Networked Control System

In the nonlinear networked control system (NCS), the conventional control method is difficult to achieve good control performance, due to the nonlinear problem associated with the disturbance factors, such as network induced time delay and data packet dropout. Considering this situation, this paper is aimed to propose a nonlinear networked control system based on T-S fuzzy model, which does not rely on specific network parameters or mathematical model. The nonlinear problem and the uncertainties of network can be both processed by the designed fuzzy controller. Then this approach is applied to nonlinear motor servo system, simulation of the example model is implemented in Matlab/Simulink associated with True Time toolbox. The results show that the proposed method not only is convenient for modeling, but also upgrade the performance of control system.

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 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.

Optimal Co-Design of Control Algorithm and Bandwidth Scheduling for Networked Control Systems

2011 ◽  
Vol 314-316 ◽  
pp. 2124-2131
Author(s):  
Rong Chen
Keyword(s):  
Control System ◽  
Networked Control Systems ◽  
Scheduling Algorithm ◽  
Continuous System ◽  
Networked Control System ◽  
Networked Control ◽  
Bandwidth Utilization ◽  
Loop Control ◽  
Integrated Simulation ◽  
Bandwidth Scheduling

The performance of Networked Control System (NCS) is not only determined by controller, but also by network QoS. In this paper, aiming at the bandwidth scheduling problem of multiple closed loop control system, an approximate linear function of continuous system performance with delay and sample period is proposed firstly, and then the optimal scheduling algorithm under both non-preemptive rate monotonic (NPRM) schedulability constraint and NCS stability constraint is proposed which is to optimize the overall performance of NCS. Moreover, an algorithm of sample periods harmonization is presented to improve the bandwidth utilization. A reservation-based schedule of non-period data is also taken into account. Finally, an integrated simulation platform based on Truetime is present, and the experimental results show that the scheme is more effective than the former ones.

A Stable Adaptive Control Method in Networked Control System

2011 ◽  
Vol 110-116 ◽  
pp. 4837-4844
Author(s):  
Yu Zhang ◽  
Peng Cheng ◽  
Teng Fei Yin
Keyword(s):  
Control System ◽  
Time Delay ◽  
Control Method ◽  
Fuzzy Controller ◽  
Sampling Period ◽  
Networked Control System ◽  
Network Control ◽  
Control Logic ◽  
Network Time ◽  
Long Time

In this paper it has made study on long time-delay network control system which is greater than one sampling period, it has made modeling on sensor node time drive, controller node and actuator node event-driven system The special question has been considered which was brought more than one sampling period delay, the fuzzy control logic has been applied in MATLAB to design an adaptive Fuzzy controller, when the network time delay changes the controller parameters can be adjusted dynamically, to make dynamic compensation on network time delay, and through simulation experiments to verify the algorithm effectiveness.

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 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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