scholarly journals Robust Sliding Mode Predictive Control of Uncertain Networked Control System with Random Time Delay

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yu Zhang ◽  
Shousheng Xie ◽  
Ledi Zhang ◽  
Litong Ren
Keyword(s):  
Control System ◽  
Time Delay ◽  
Sliding Mode ◽  
Networked Control System ◽  
Networked Control ◽  
Random Time ◽  
System Stability ◽  
Sliding Surface ◽  
Predictive Controller ◽  
Global Sliding Surface

This paper proposes a sliding mode predictive controller with a new robust global sliding surface for a certain networked control system with random time delay, mismatched parametric uncertainty, and external disturbances. First, the model of the networked control system is established, based on which linear transformation is made to get a new form of the system which does not have time delay term in expression. Then a global sliding surface is proposed followed by the sufficient condition given in the form of linear matrix inequality (LMI) to guarantee system stability and robustness. Subsequently, a sliding mode predictive controller is proposed with modified reaching law as its reference trajectory and the rolling optimization method is combined to provide optimal control input for each step so that chattering can be minimized. Finally, simulations have been made and the results indicate the advantages of the proposed controller in the aspect of convergence speed, chattering suppression, and robustness to uncertainties.

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 Predictive Controller Design for Networked Control System

2019 ◽  
Vol 9 (1) ◽  
pp. 5246-5250
Keyword(s):  
Control System ◽  
Time Delay ◽  
Process Model ◽  
Controller Design ◽  
Correct Choice ◽  
Networked Control System ◽  
Networked Control ◽  
Time Sharing ◽  
Predictive Controller ◽  
Stability Time

A networked control system where sensor ( ), controller ( ) and an actuator ( ) are interacting to the process model or system through a communication channel. The model reliability depends on time delay of data transmission from to , to , controller processing time and packet dropouts. In this proposed work, model based network system is designed to achieve the desired response of the controlled system by minimizing the network time delay and improves con-troller performance in term of stability. Time delay mainly occurs due to time sharing of the medium as well extra overload of signal coding and processing phase. The time delays could be steady, limited, or even random, depends upon protocol used in the network and hardware. The network predictive control tech-nique effectively works on random delay. The predictive controller is used to analyses the future output conditions of the system based on the previous values. The simulated result shows that if time delay increases, the response of the system degraded and therefore for improving it the correct choice of prediction and control horizon is needed. The designed networked control system based on predictive functional control is simulated using True Time tool on Matlab. The ob-tained outcomes from the proposed technique accomplishes that the technique is effective and feasible.

Study of Predictive Control in Industrial Networked Control System

2011 ◽  
Vol 201-203 ◽  
pp. 2087-2090
Author(s):  
Fang He ◽  
Xiao Li ◽  
Qiang Wang
Keyword(s):  
Control System ◽  
Time Delay ◽  
Predictive Control ◽  
Networked Control System ◽  
Networked Control ◽  
Model Mismatch ◽  
Network Time ◽  
Study Results ◽  
Predictive Controller ◽  
Uncertain Time

In order to improve the performance of networked control system which has the characteristic of uncertain time delay, predictive control is adopted. The model of networked control system is analyzed. Take into account uncertain network time delay caused by various factors and problem of model mismatch, predictive controller is designed and simulation model of system is built using software of Matlab. A method of reducing model mismatch is proposed. Study results show that predictive control can make networked control system with good performance.

Predictive control compensation for networked control system with time-delay

2021 ◽  
pp. 095965182110182
Author(s):  
Zhongda Tian ◽  
Yanhong Wang
Keyword(s):  
Control System ◽  
Time Delay ◽  
Predictive Control ◽  
Control Variable ◽  
Networked Control System ◽  
Compensation Method ◽  
Networked Control ◽  
Delay Compensation ◽  
Predictive Controller ◽  
Time Delay Compensation

This study proposes a novel predictive control compensation method to deal with random time-delay in networked control system. Different from other compensation strategies, this study adopts different compensation strategies for input time-delay and output time-delay to improve the control effect. First, for the input channel time-delay, the corresponding buffer is set by the time-stamp in the packet. Combining the historical output value and the control variable, the fast implicit generalized predictive control algorithm is adopted to design the predictive controller to compensate for the input channel time-delay. Second, for the output channel time-delay, the controller cannot measure it. A control compensator is designed by adding a feedback loop. The output control variable of the predictive controller is adjusted by predicting the error between the actual control signal and the controller output at the historical sampling time, so as to compensate for the time-delay of the output channel. In addition, the stability of the proposed time-delay compensation method is analyzed. Finally, simulation and experimental results show that the proposed method has good control and compensation effect, and improves the output performance of the system. The networked control system with random time-delay is stable. Furthermore, the simulation results also show that this time-delay compensation method needs less computing time and is more suitable for the practical applications.

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