Stability Condition For Networked Control Systems Research Articles

Control of networked systems with packet loss and channel uncertainty

This study considers the control problem of networked control systems (NCSs) concerning both bounded channel uncertainty and packet loss. First, the authors deal with the problems of state feedback control for NCSs concerning both bounded random packet loss and channel uncertainty. Based on a previous work which copes with packet loss only, a classic model is used to describe the NCS with both packet loss and channel uncertainty in an unified framework. The stability conditions of NCSs are given by a common quadratic Lyapunov function and an approach is given to design the dynamic feedback controller via solving linear matrix inequalities. Second, the problems of output feedback control for NCSs concerned both bounded random packet loss and channel uncertainty are considered. A new sufficient condition is developed to guarantee the exponentially mean square stability of closed-loop networked systems and by using the stability theory, the controller and observer design problem is solved. Finally, numerical simulations and practical experiments are given to show the effectiveness of both approaches.

Robust Fault-Tolerant Control for Uncertain Networked Control Systems with State-Delay and Random Data Packet Dropout

A robust fault-tolerant controller design problem for networked control system (NCS) with random packet dropout in both sensor-to-controller link and controller-to-actuator link is investigated. A novel stochastic NCS model with state-delay, model uncertainty, disturbance, probabilistic sensor failure, and actuator failure is proposed. The random packet dropout, sensor failures, and actuator failures are characterized by a binary random variable. The sufficient condition for asymptotical mean-square stability of NCS is derived and the closed-loop NCS satisfiesH∞performance constraints caused by the random packet dropout and disturbance. The fault-tolerant controller is designed by solving a linear matrix inequality. A numerical example is presented to illustrate the effectiveness of the proposed method.

Modelling and robust stability of networked control systems with packet reordering and long delay

In this article, modelling and robust stability of networked control systems (NCS) are discussed. Considering the existence of packet reordering and network-induced delay, a new mathematical model of NCS whose network-induced delay is longer than one sampling period is obtained, which can fully describe packet reordering and effectively eliminate the impact of packet reordering on the performance of NCS such that the newest control input can be executed by the actuator. Based on this model, the time-varying NCS is converted into an uncertain discrete linear system with multi-step delay in terms of matrix theory. Furthermore, a sufficient condition for robust stability of NCS is presented. Linear matrix inequality approach has been employed to solve the controller design problems. Numerical examples are compared with previous schemes to demonstrate the effectiveness of the proposed method.

Predictive observer‐based control for networked control systems with network‐induced delay and packet dropout

AbstractThis paper addresses the stability analysis and synthesis problems for a class of networked control systems (NCSs) under effects of both network‐induced delay and packet dropout. The motivation comes from the increasing NCS applications where the full state vector is not available. To handle the concerned problems, two predictive observer‐based controllers are constructed. The first one is a memoryless controller with the predictive observer collocated with the plant. The second one, with the predictive observer colocated with the controller, uses the last effective plant information as well as the knowledge of the plant dynamics. The stability conditions of NCSs are derived via both network‐condition‐dependent Lyapunov function and common quadric Lyapunov function. The corresponding controller design problems are also solved based upon the obtained stability conditions. Simulation and experimental results are given to demonstrate the effectiveness of the proposed approaches. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society

State feedback controller design of networked control systems with multiple-packet transmission

This paper studies the stability analysis and state feedback controller design of continuous-time networked control systems (NCSs). A model of NCSs with multiple-packet transmission and packet dropout in both the sensor-to-controller channel and controller-to-actuator channel is given, then a stability condition for NCSs with multiple-packet transmission is presented, and a new method for controller design is also proposed by using an LMI-based method. The simulation results illustrate the effectiveness of the controller design for NCSs with multiple-packet transmission.