Stability analysis of networked control systems with compensation for data packet dropout

This paper concerns the problem of the model, stability and controller design for networked control system (NCS) with time-varying delay and dropped out packet. For the NCS with time-varying delay and data packet dropout, four new control methods of dynamical state feedback control, dynamical state feedback proportional-integral (PI) control, state feedback proportional-derivative (PD) control and dynamical state feedback PD control are presented. The NCS with time-varying delay and data packet dropout based on the four control methods is modeled as an asynchronous dynamical system (ADS) constrained by event rates. Furthermore, based on the ADS theory, principle of Lyapunov stability and method of linear matrix inequality, both the semi-negative definite matrix conditions of exponential stability and the controller design for NCS are given. Finally, numerical example illustrates the feasibility of the results.

The problem of stabilization of networked control systems (NCSs) with data packet dropout is studied. Sufficient conditions are presented on the stability and stabilization of the NCSs with packet dropout. The novelty of this work lies in that NCSs with arbitrary but finite data packet dropout are modelled as switched linear systems, and this enables us to apply the result of switched systems to the analysis and synthesis of such NCSs. The admissible upper bound of the dropped packets can be determined by a set of linear matrix inequalities (LMIs) which guarantee the stability of the NCSs. Stabilizing controllers (via state feedback and static output feedback) can be constructed by solving a set of LMIs. Also, for an NCS with a convergence rate constraint, similar results are obtained. Examples are worked out to illustrate the effectiveness of the proposed method

The controller design techniques for Networked Control Systems (NCSs) with uncertain, time-varying network induced delay and data packet dropout is studied. A state predictor is used to predict current plant states, predicted states is used to construct control law. Combined with the state predictor, the NCS with long time delay and data packet dropout is modelled as asynchronous dynamical system with event rate constraints. Based on the model, sufficient conditions of exponential stability for NCS are given in the form of matrix inequalities. Through the feasible solution of the matrix inequalities the control law can be obtained. A numerical example demonstrates the effectiveness of the proposed method.

Although there has been a lot of work about the synthesis and analysis of networked control systems (NCSs) with quantizers as well as NCSs with packet losses, most results are developed for the case of considering the quantizers and packet losses separately (either only concentrating on the data quantization or only focussing on the packet losses). In this paper, we address the synthesis approach of model predictive control (MPC) for NCSs subject to both data quantization and packet losses. This is motivated by the fact that it is common and natural in NCSs that the issues of the quantization and packet losses are coexisting. We firstly propose a novel model to describe the state and input quantization and the packet losses of the NCS in a unified framework. Further, from the new model, a MPC strategy is developed, which can guarantee the recursive feasibility. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

Based on the controlled process that is linear time-invariant system, the network-induced long time delay is viewed as time-varying parameter uncertainties. The uncertainty parameters model of networked control systems with long time delay is set up. The existing conditions of asymptotic stability for networked control system with long time delay are presented by Lyapunov method and robust control theory. The design method of stabilization controller for networked control system is proposed in terms of linear matrix inequalities. In the end the simulation based on the networked control unstable system is studied. The simulation results show the proposed controller is feasible and effective.

This paper studies the problem of the exponential stability of networked control systems (NCSs) with large delay periods, which often appear in the transmission of NCSs. Some new concepts about large delay periods are introduced, and a method based on switching is employed. The maximum allowable transfer interval is obtained such that the considered system is exponentially stable. The criteria obtained contain existing results without considering a large delay period as a special case. An example is given to show the effectiveness of the proposed criteria. Copyright © 2009 John Wiley & Sons, Ltd.

The problem of data packet dropout induced by communication channel in networked control systems (NCSs) is studied in this paper. We model the NCSs with data packet dropout as jump linear systems. With a freedom matrix introduced, new equivalently sufficient conditions on the mean square stabilisation of NCSs are obtained in terms of linear matrix inequalities (LMIs). Constant stabilising state-feedback controllers can then be constructed by using the feasible solutions of some LMIs. A numerical example illustrates the effectiveness of the proposed approach.

Research on mean square exponential stability of networked control systems with multi-step delay

A new control mode is proposed for a networked control system whose network-induced delay is longer than a sampling period. A time-division algorithm is presented to implement the control and for the mathematical modeling of such networked control system. The infinite horizon controller is designed, which renders the networked control system mean square exponentially stable. Simulation results show the validity of the proposed theory.

The problem of stabilization of networked control systems (NCSs) with time-varying transmission delays is investigated. The time-varying delays lie in any two adjoining sampling instants of the plant. A technique is proposed for designing stabilizing controllers by converting NCSs with time-varying transmission delays into parameter uncertain systems with constant input delay, then the theory of robust stabilization of delay systems can be applied to solving this problem. Sufficient condition on stabilization of such NCSs is developed in terms of linear matrix inequality.

Delay-dependent stability criteria for a class of networked control systems with multi-input and multi-output☆

The presence of a communication network in a control loop induces many imperfections such as varying transmission delays, varying sampling/transmission intervals, packet loss, communication constraints and quantization effects, which can degrade the control performance significantly and even lead to instability. Various techniques have been proposed in the literature for stability analysis and controller design for these so-called networked control systems. The aim of this chapter is to survey the main research lines in a comprehensive manner.

A new method for modeling and analysis of networked control systems with time delay using hidden Markov models is presented. The optimal estimator of system state for networked control systems without full state information is given when the networked induced time delay is governed by an underlying Markov chain. The design of stochastic optimal controllers of networked control systems with output feedback is also presented. The result of simulation verified the efficiency and correction of the proposed methods.

In this paper, a new approach to event-triggered H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance analysis of linear networked control systems is proposed. First, a new parametrization of event-triggering scheme is designed, in which a positive diagonal parameter matrix with n elements (corresponding to the dimension of the system under consideration) is introduced, resulting in different weights for each state component. Under this event-triggered formulation together with delay system modeling approach and a discontinuous Lyapunov functional, the criteria for H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance analysis are derived in terms of linear matrix inequalities. Finally, simulation results on a practical example are given to indicate that the proposed method has some advantages over some existing ones.

Recent technological advances have enabled distributed control systems to be implemented via networks. This allows feedback control loops to be closed over a shared communication channel. Network-induced delays are inevitable, however, when transmitting digital data between control devices. This paper analyzes the stability of such networked control systems (NCS). We first review some previous work on this topic, offering some improvements. We analyze the influence of the sampling rate and network delay on system stability. We further study the stability of NCS using a hybrid system stability analysis technique.