Mixed H_/H∞ fault detection observer design for networked control system with variable sampling period

2014 ◽  
Vol 21 (1) ◽  
pp. 38 ◽  
Author(s):  
Jin rong Fan ◽  
Hua jing Fang
Keyword(s):  
Control System ◽  
Fault Detection ◽  
Sampling Period ◽  
Networked Control System ◽  
Observer Design ◽  
Networked Control ◽  
Variable Sampling

Scheduling method for networked control system with resource constraints based on fuzzy feedback priority and variable sampling period

2016 ◽  
Vol 40 (4) ◽  
pp. 1136-1149 ◽  
Author(s):  
Tian Zhongda ◽  
Li Shujiang ◽  
Wang Yanhong ◽  
Wang Xiangdong
Keyword(s):  
Control System ◽  
Data Transmission ◽  
Resource Constraints ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Control Loop ◽  
Network Utilization ◽  
Variable Sampling ◽  
Scheduling Method

A scheduling method based on fuzzy feedback priority and variable sampling period for a networked control system with resource constraints is proposed in this paper. Firstly, each control loop weight is adjusted dynamically according to a control loop data transmission error through a quadratic square root mapping function. A different weight is given for each loop. A fuzzy feedback priority scheduling strategy is designed combined with dynamic weight, system output and system output error rate. The priority of each control loop is adjusted dynamically. Then, considering the current network status, the new network utilization is predicted through proportional control. A least-squares support vector machine (LSSVM) algorithm is used for controlled loop packet transmission time prediction. A variable sampling period for each control loop is determined by using a controlled loop dynamic weight, network utilization and data transmission time. Finally, a fuzzy feedback priority scheduler and variable sampling period scheduler are combined. The merits of the two schedulers are utilized to achieve the optimization goal. A simulation experiment is carried out using the True Time toolbox. Simulation results show that the scheduling method can make the network utilization rate converge to the desired value under resource constraints, improve the output response performance of the control loop, reduce the integral absolute error value of the control loop and decrease the data transmission time of the control loop. The networked control system performance is improved and the scheduling method of this paper is effective.

Deadband feedback-based scheduling approach for networked control system with variable sampling period

2021 ◽  
pp. 014233122098142
Author(s):  
Zhongda Tian
Keyword(s):  
Control System ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Control Performance ◽  
Control Loops ◽  
Network Bandwidth ◽  
Network Utilization ◽  
Variable Sampling ◽  
Overall Performance

Reasonable information scheduling strategies in the networked control system (NCS) can improve the quality of service of the network, reduce the conflict of information transmission in the network, and improve the overall performance of the NCS. In order to improve the performance of the NCS, a deadband feedback-based scheduling approach for the NCS with a variable sampling period is proposed. For the NCS with multi control loops, considering the limitation of network bandwidth resources, the dynamic real-time adjustment of a multi-loop sampling period is achieved through network utilization prediction, network bandwidth configuration and sampling period calculation. Furthermore, deadband feedback scheduling is combined with a variable sampling period algorithm. Deadband is set in the sensor and controller nodes to effectively adjust the information flow of the forward channel and the feedback channel. The proposed scheduling approach can reduce the impact of network conflict and network delay on system stability, make the network resources allocated reasonably, save network data traffic, and improve the overall performance of the NCS. A NCS with five control loops is used as the simulation object and carried out by True Time toolbox. The simulation results show that the proposed scheduling approach can improve output control performance of the system, reduce integral absolute error value of the control loops, and improve network utilization. The overall control performance of the system is improved.

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