Stochastic Packet Losses Research Articles

[formula omitted] control of uncertain T–S fuzzy networked control systems with actuator faults under stochastic packet loss-dependent event-triggered schemes

In this paper, the H∞ control problem of uncertain T–S fuzzy networked control systems (NCSs) with actuator faults under stochastic packet loss-dependent event-triggered schemes (SPDETS) is investigated. First, in order to improve the efficiency of communication networks, an innovative SPDETS is proposed, which relies on stochastic packet losses during data transmission and event-triggered conditions. Second, a packet loss-dependent switching-like controller is designed to maintain the control performance of the system. Third, some potential actuator faults are taken into account, besides considering system uncertainty and network-induced delay. Using the Lyapunov–Krasovskii theorem, sufficient conditions to guarantee the system stability for a specified performance index are presented, and design conditions are given for a switching-like fault-tolerant controller that compensates for the actuator efficiency loss. Finally, the effectiveness of the proposed control scheme is verified through the CSTR simulation example.

Mixed [formula omitted] control for discrete-time periodic Markov jump systems with quantization effects and packet loss compensation

This article concentrates on the issue of the mixed H2/H∞ state feedback control for discrete-time periodic Markov jump systems with quantization effects and packet loss compensation. Considering that the communication channel is limited, the state signals need to be quantized by a logarithmic quantizer with mode-dependent property before communication. When the quantized state is passed to the controller, the stochastic packet loss phenomenon may occur, which follows Bernoulli stochastic distribution. Therefore, a new packet loss compensation strategy is put forward, which adopts the single exponential smoothing method to predict the lost data. Additionally, considering that the system modes are not always fully available, a periodic controller with partially mode-dependent property is devised to ensure that the system is stochastically stable with the predefined mixed H2/H∞ performance. Then, the sufficient conditions for the existence of periodic controller are established by constructing a periodic Lyapunov function, which is mode-dependent. Ultimately, a practical example of a boost converter is presented to verify the validity of the proposed approach.

Observer-based control for networked Takagi-Sugeno fuzzy systems with stochastic packet losses

This paper addressed the observer-based control problem for Takagi-Sugeno (T-S) fuzzy systems with stochastic packet losses. More specifically, an sampled-data (SD) control technique is introduced to reduce the burden of the limited bandwidth of the network, a general consecutive packet loss model is used to represent the stochastic packet loss behavior between sensor-to-controller and controller-to-actuator, and an observer scheme based on received SD output information is used to obtain the estimated system states. Based on the above scenarios, an exact discrete-time model approach is developed for stabilizing networked T-S fuzzy systems. First, the considered system with the observer-based control scheme is transformed into its discrete-time model such that subsequent analysis will be carried out in the discrete-time domain. On this basis, stability criteria are derived by fully considering the probability distribution of consecutive packet losses. Furthermore, an observer-based controller is designed by introducing some auxiliary matrices. Finally, the correctness and practicability of the designed controller is demonstrated by a mass-spring-damper system.

Consensus of discrete-time multi-agent systems with consecutive packet losses in directed communication topology

In this paper, consensus analysis and design are investigated for discrete-time multi-agent systems (MASs) with consecutive packet losses in communication links of directed communication topology. It is assumed that at each transmitted instant, the packet loss is stochastic and described by Bernoulli distribution, but during a given time window, the data could be successfully transmitted to the agent from each of its neighbors. First, we utilize the incidence matrix of a directed spanning tree of the communication topology to construct a linear transformation matrix so that the consensus problem is equivalently transformed into a mean square asymptotic stability problem of a reduced-order system. Second, by using Lyapunov–Krasovskii functional approach, we derive some sufficient conditions of consensus criterion in terms of linear matrix inequalities (LMIs). These conditions express the relationship among the control gain matrix, packet loss rate, and the number of consecutive packet losses. Based on the conditions, gain matrix in the consensus protocol is designed to guarantee the MAS with stochastic packet losses to achieve mean square asymptotic consensus. Moreover, for the special case of undirected communication topology, by using the matrix decomposition method, the variables of LMIs are transformed into the low-order conditions independent of the network size. Finally, some numerical examples are given to show the effectiveness of the proposed method.

Robust Performance Analysis for Time-Varying Multi-Agent Systems with Stochastic Packet Loss

Recently, a scalable approach to system analysis and controller synthesis for homogeneous multi-agent systems with Bernoulli distributed packet loss has been proposed. As a key result of that line of work, it was shown how to obtain upper bounds on the H2-norm that are robust with respect to uncertain interconnection topologies. The main contribution of the current paper is to show that the same upper bounds hold not only for uncertain but also time-varying topologies that are superimposed on the stochastic packet loss. Because the results are formulated in terms of linear matrix inequalities that are independent of the number of agents, multi-agent systems of any size can be analysed efficiently. The applicability of the approach is demonstrated on a numerical first-order consensus example, on which the obtained upper bounds are compared to estimates from Monte-Carlo simulations.

Practical Fixed-Time Consensus Tracking for Multiple Euler–Lagrange Systems With Stochastic Packet Losses and Input/Output Constraints

In this article we investigate the practical fixed-time consensus tracking problem for multiple Euler–Lagrange systems, which is subject to, concurrently, stochastic packet losses in directed communication networks (DCNs) and input/output constraints. In practice, the packet losses in the communication network may lead to communication failure and control accuracy degradation. To address this impact, a novel fully distributed observer is established to estimate the leader’s states within fixed time. Subsequently, the state constraint function is introduced so that the designed adaptive control protocol can be used in a uniform structure with unconstrained or asymmetric/symmetric output constraints without changing the adaptive structure. Combining the backstepping technique with fuzzy-logic systems, an adaptive fixed-time local control protocol is constructed to drive each agent to track the leader’s states estimated by the observer. Besides, a novel auxiliary system is introduced to solve the constraint problem of the control input. Furthermore, through rigorous theoretical analysis, it is verified that all signals converge to the compact set close to zero with guaranteed fixed-time convergence rate. At last, a representative simulation is carried out to demonstrate the practicability of the proposed method.

Corrections to “Practical Fixed-Time Consensus Tracking for Multiple Euler–Lagrange Systems With Stochastic Packet Losses and Input/Output Constraints” [2021 DOI: 10.1109/JSYST.2021.3112720

In [1], several errors were introduced during the production process, which are corrected here.

Performance evaluation of industrial ethernet protocols for real-time fault detection based adaptive observer in networked control systems with network communication constraints

<p>In this paper, the performance evaluation of industrial ethernet (EtherNet/IP, EtherCAT and PROFINET IRT) networks has been studied for choosing the right protocol in real-time fault detection based adaptive sliding mode observer in networked control systems (NCSs) under time network-induced delays, stochastic packet losses, access constraints and bounded disturbances. An adaptive sliding-mode observer based fault detection is presented. The dynamic hydroelectric power plant model is used to verify the effectiveness of the proposed method based on TrueTime and Matlab/ Simulink, corroborated our predictions that an ethernet for control automation technology (EtherCAT) protocol would be more appropriate to reduce the false alarm rate and increasing the efficiency of the remote control of industrial hydroelectric power plant.</p>

Adaptive sliding mode control for 2D nonlinear Fornasini–Marchesini model subject to quantisation and packet dropouts

This paper aims to solve the sliding mode control issue for the discrete nonlinear two-dimensional (2D) Fornasini–Marchesini second (FMII) model under the influence of quantisation error and stochastic packet loss. Firstly, an innovative stochastic 2D FMII sliding mode control model is constructed by considering quantisation error and Bernoulli packet loss process. And then we study the stability issue and formulate the corresponding stability criterion by virtue of the 2D sliding mode surface and a 2D sliding mode control law with data compensation. Subsequently, the reachability for the 2D sliding surface is verified by a innovative and executable 2D sliding mode control law. Besides, the article also formulates the adaptive intelligent iterative algorithms for the sliding mode surface gain and 2D sliding mode control algorithm, respectively. To conclude the paper, an example is provided to analyse its SMC problem under quantisation and stochastic packet loss. This example also shows the effectiveness of the theorems and algorithms proposed in this paper.

Robust Mixed H2/H∞ Control for An Uncertain Wireless Sensor Network Systems with Time Delay and Packet Loss

In this paper, the problem of robust mixed H2/H∞ control is studied for an uncertain wireless sensor network (WSN) systems with random time delay, packet loss and sensor faults. A system model is established based on the characteristics of uncertain time delay and packet loss in WSN. In this model, system uncertainties are represented by random time delay and stochastic packet loss, which are described by a Markov chain. By using a Lyapunov-Krasovskii function, a mode-dependent mixed H2/H∞ controller is designed to guarantee both the stochastic stability of the closed-loop system and the prescribed H2, H∞ control performances. The sufficient conditions for the existence of the controller are proved by a series of Linear Matrix Inequalities (LMIs). If these LMIs are feasible, the mode-dependent mixed H2/H∞ controller can be obtained. Matlab LMI toolbox is used to calculate the control law. Finally, a numerical example and its simulation results demonstrated the effectiveness of the proposed method.

Modelling and stabilisation of networked control system with packet loss and time-varying delays

The modelling and stabilising control of networked control systems (NCSs) with stochastic packet loss and time-varying delays are addressed. In specific, a novel Markovian jump linear system with time-varying delays is used to model the NCS. Without using the augmented state method, sufficient conditions for the stochastic stabilisation of the NCS with packet loss and time-varying delays are obtained via the mode-dependent Lyapunov function method. The mode-dependent controller for the closed-loop NCS is presented in the linear matrix inequalities formulation via the Shur complement theory. A numerical example is given to illustrate the effectiveness of the proposed method.

Tradeoffs between quantization and packet loss in networked control of linear systems

In this paper, we consider to derive the coarsest memoryless quantizer which can stabilize a single-input discrete-time linear time-invariant system with stochastic packet loss in the sense of stochastic quadratic stability. We show that the upper bound of the coarseness is strictly given by the packet loss probability and the unstable poles of the plants. We furthermore deal with permissible dead-zone width around the origin of the quantizers and time-varying finite quantizers in order to realize control using finite quantization steps.

Effects of network communications on a class of learning controlled non-linear systems†

In this article, an iterative learning control approach is proposed for a class of sampled-data non-linear systems over network communication channels. The effects of constant time delays and stochastic packet loss are discussed and demonstrated by simulation results. The focus of this article is to study the remote control problems when the environment is periodic or repeatable over iterations in a fixed finite interval. Because of the existence of time delays and packet loss in input and output signal transmissions, it is not trivial to accomplish the remote stabilisation task of any system. Moreover, to track a desired trajectory through a remote controller is even more difficult. Previous cycle-based learning method is incorporated into the network-based control for a class of non-linear systems which satisfies a global Lipschitz condition. The convergence property of this approach is proven. Furthermore, the convergence in the iteration domain is also discussed when there exists packet loss in both transmission channels of the system. Finally, one single-link rigid robot is given as an example to show the effectiveness of the proposed approach. †Final version for the International Journal of Systems Science.

Stochastic Packet Loss Model to Evaluate QoE Impairments

SUMMARY The estimation of quality for real-time services over telecommunication netb4works requires realistic models for impairments and failures during transmission. We focus on the classical Gilbert-Elliott model whose second-order statistics is derived over arbitrary time-scales. The model is used to fit packet loss processes of backbone and DVB-H traffic traces. The results show that simple Markov models are appropriate to capture the observed loss pattern and to discuss how such models can be used to examine the quality degradations caused by packet losses.

Networked fault detection with random communication delays and packet losses

This article deals with the fault detection problem for a class of discrete-time networked systems with multiple state delays and unknown input. Two kinds of incomplete measurements, namely measurements with random communication delays and measurements with stochastic packet losses, are simultaneously considered. By properly augmenting the states of the original system and the fault detection filter, the fault detection filter design problem can be formulated as an H ∞ filtering problem. Attention is focused on the design of a fault detection filter such that, for all unknown input and incomplete measurements, the error between residual and weighted fault is made as small as possible. A sufficient condition for the existence of the desired fault detection filter is established in terms of a linear matrix inequality. A numerical example is provided to illustrate the effectiveness and applicability of the proposed techniques.

Feedback Control via AmI-Networks – Managing the Limited Resource Problem by QoS-Adaptive Control (Regelungen über ressourcenbeschränkte AmI-Netzwerke durch Adaption an die Quality of Service)

Ambient Intelligence (AmI) systems are typically based on low-energy and low-performance nodes which are connected by wireless ad-hoc networks. Due to these constraints communication is restricted as well, as can be seen from the quality of service (QoS) parameters. If feedback control is used in AmI systems, two main effects are limiting the control performance and threatening the control stability: the variable network delays and the stochastic packet losses. The paper describes an approach taking into account these crucial parameters at the same time. This problem is solved by adapting the control law to the measured QoS parameters of the ad-hoc network. An example is discussed to show the advantages of the proposed QoS-adaptive control.