Optimal Bandwidth Allocation and QoS-Adaptive Control Co-Design for Networked Control Systems

2007 ◽  
Author(s):  
Kun Ji ◽  
Won-Jong Kim
Keyword(s):  
Adaptive Control ◽  
Control Systems ◽  
Bandwidth Allocation ◽  
Design Methodology ◽  
Networked Control Systems ◽  
Networked Control ◽  
Control Performance ◽  
Control Loop ◽  
Network Bandwidth

In this paper, we present a co-design methodology of dynamic optimal network-bandwidth allocation (ONBA) and adaptive control for networked control systems (NCSs) to optimize overall control performance and reduce total network-bandwidth usage. The proposed dynamic co-design strategy integrates adaptive feedback control with real-time scheduling. As part of this co-design methodology, a “closed-loop” ONBA algorithm for NCSs with communication constraints is presented. Network-bandwidth is dynamically assigned to each control loop according to the quality of performance (QoP) information of each control loop. As another part of the co-design methodology, a network quality of service (QoS)-adaptive control design approach is also presented. The idea is based on calculating new control values with reference to the network QoS parameters such as time delays and packet losses measured online. Simulation results show that this co-design approach significantly improves overall control performance and utilizes less bandwidth compared to static strategies.

Variable Deadband Sampling and T-S Fuzzy PID Co-Design for Optimizing QoS and QoP of Wireless Networked Control Systems

2013 ◽  
Vol 658 ◽  
pp. 502-507
Author(s):  
Guo Fu Tang ◽  
Yan Xin Zhang
Keyword(s):  
Control Systems ◽  
Networked Control Systems ◽  
Networked Control ◽  
Network Services ◽  
Control Performance ◽  
Fuzzy Pid ◽  
Control Loop ◽  
Quality Of Control ◽  
Comparison Results

Variable deadband sampling is used in wireless networked control systems to reduce the network message. In this paper the T-S fuzzy PID with variable deadband sampling is designed to optimize the quality of network services and the quality of control performance in closed control loop. Furthermore, Kalman filtering algorithms dealing with variable deadband sampling are considered in the paper. The comparison results of proposed method and PID with period sampling are presented based on the extensive simulations by using TrueTime 1.5 toolbox for Matlab/simulink, and the simulation results verify the effectiveness of the proposed method.

scholarly journals H∞Guaranteed Cost Control for Networked Control Systems under Scheduling Policy Based on Predicted Error

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Qixin Zhu ◽  
Kaihong Lu ◽  
Yonghong Zhu
Keyword(s):  
Control Systems ◽  
Prediction Error ◽  
Networked Control Systems ◽  
Design Method ◽  
Networked Control ◽  
Collision Probability ◽  
Linear Matrix ◽  
Scheduling Policy ◽  
Network Bandwidth ◽  
Guaranteed Cost

Scheduling policy based on model prediction error is presented to reduce energy consumption and network conflicts at the actuator node, where the characters of networked control systems are considered, such as limited network bandwidth, limited node energy, and high collision probability. The object model is introduced to predict the state of system at the sensor node. And scheduling threshold is set at the controller node. Control signal is transmitted only if the absolute value of prediction error is larger than the threshold value. Furthermore, the model of networked control systems under scheduling policy based on predicted error is established by taking uncertain parameters and long time delay into consideration. The design method ofH∞guaranteed cost controller is presented by using the theory of Lyapunov and linear matrix inequality (LMI). Finally, simulations are included to demonstrate the theoretical results.

Bandwidth Allocation of Networked Control Systems With Exponential Approximation

2013 ◽  
Author(s):  
Jiawei Dong ◽  
Won-jong Kim
Keyword(s):  
Control Systems ◽  
System Performance ◽  
Bandwidth Allocation ◽  
Networked Control Systems ◽  
Sampling Frequency ◽  
Networked Control ◽  
Optimal Sampling ◽  
Exponential Approximation ◽  
Bandwidth Utilization ◽  
Programming Techniques

This paper investigates bandwidth allocation of networked control systems (NCSs) with nonlinear-programming techniques. The bandwidth utilization (BU) is defined in terms of sampling frequency. An exponential approximation is formulated to describe system performance versus the sampling frequencies. The optimal sampling frequencies are obtained by solving the approximation with Karush-Kuhn-Tucker (KKT) conditions. Simulation and experimental results verify the effectiveness of the proposed approximation. The exponential approximation can minimize the BU so that the plants can be scheduled along with the system PIFs being optimized.

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