Age-of-information vs. value-of-information scheduling for cellular networked control systems

In the design of multi-loop Networked Control Systems (NCSs), wherein each control system is characterized by heterogeneous dynamics and associated with a certain set of timing specifications, appropriate metrics need to be employed for the synthesis of control and networking policies to efficiently respond to the requirements of each control loop. The majority of the design approaches for sampling, scheduling, and control policies include either time-based or event-based metrics to perform pertinent actions in response to the changes of the parameters of interest. We specifically focus in this article on Age-of-Information (AoI) as a recently-developed time-based metric and threshold-based triggering function as a generic Event-Triggered (ET) metric. We consider multiple heterogeneous stochastic linear control systems that close their feedback loops over a shared communication network. We investigate the co-design across the NCS and discuss the pros and cons with the AoI and ET approaches in terms of asymptotic control performance measured by Linear-Quadratic Gaussian (LQG) cost functions. In particular, sampling and scheduling policies combining AoI and stochastic ET metrics are proposed. It is argued that pure AoI functions that generate decision variables solely upon minimizing the average age irrespective of control systems dynamics may not be able to improve the overall NCS performance even compared with purely randomized policies. Our theoretical analysis is validated through several simulation scenarios.

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Robust Reliability Design for Networked Control Systems Based on Information Scheduling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.179-180.43 ◽

2011 ◽

Vol 179-180 ◽

pp. 43-48

Author(s):

Zhi Hong Huo ◽

Yuan Zheng ◽

Bo Qu

Keyword(s):

Control Systems ◽

Communication Networks ◽

Networked Control Systems ◽

Fault Tolerant ◽

Sufficient Conditions ◽

White Paper ◽

Networked Control System ◽

Networked Control ◽

Linear Matrix ◽

Information Scheduling

This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.Networked Control Systems (NCS) are systems with at least one loop closed through data networks. The existence of real-time network in the feedback control loop makes it more complex to analyze and design the NCS. In this paper, the networked control systems with network-induced delay, parameters uncertainty and packet loss which are induced by the limited bandwidth of communication networks is modeled, consider the sensors that can’t send information to controller and the actuators that can’t receive information calculated and sent by the controller, the integrity design of the networked control system with sensors failures and actuators failures is analyzed based on information scheduling and robust fault-tolerant control theory. Sufficient conditions, based on Lyapunov function method, are established in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, the explicit expression of the controller can also be characterized. After detailed theoretical analysis, the simulation results is provided, which further demonstrated the proposed scheme.

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