Round-Robin Protocol Research Articles

Observer-based state estimation for discrete-time semi-Markovian jump neural networks with round-robin protocol against cyber attacks

This paper investigates an observer-based state estimation issue for discrete-time semi-Markovian jump neural networks with Round-Robin protocol and cyber attacks. In order to avoid the network congestion and save the communication resources, the Round-Robin protocol is used to schedule the data transmissions over the networks. Specifically, the cyber attacks are modeled as a set of random variables satisfying the Bernoulli distribution. On the basis of the Lyapunov functional and the discrete Wirtinger-based inequality technique, some sufficient conditions are established to guarantee the dissipativity performance and mean square exponential stability of the argument system. In order to compute the estimator gain parameters, a linear matrix inequality approach is utilized. Finally, two illustrative examples are provided to demonstrate the effectiveness of the proposed state estimation algorithm.

Set membership filtering for discrete saturated time‐varying networked systems with incomplete measurements under round‐robin protocol

AbstractIn this paper, the set membership filtering problem is investigated for a class of discrete networked systems with time delay and state saturation under the round‐robin (RR) protocol, where the system noise is unknown but bounded. In order to reduce the communication burden, the RR protocol is used to schedule the measurement information of the system. In addition, the incompleteness of the measurement information is considered. A set membership filter is established based on incomplete measurements. The objective is to give a criterion that the filtering error is confined to the ellipsoidal set by using the recursive linear matrix inequality (RLMI) method. Moreover, a convex optimization method is proposed to minimize the obtained ellipsoids. Finally, a numerical simulation illustrates that the designed set membership filtering scheme is effective.

Event-triggered [formula omitted]-gain control for networked systems with time-varying delays and round-robin communication protocol

This paper studies the event-triggered (ET) L2-gain control issues for time-delay networked control systems (NCSs) subject to round-robin protocol. The considered NCS consists of n sensor nodes, where the communication from the sensors to the controller is scheduled by round-robin protocol. This protocol requires that, at every sampling instant, only one sensor is chosen to use the sensor/controller network and transmits its measurement information toward the controller. On the other hand, the ET strategy is adopted in the controller/actuator network, which means that the actuator will receive the updated control input signal in the situation that the predefined ET conditions are satisfied. The utilization of round-robin protocol and ET strategy will help to relieve the burden of network transmission. The network resources and bandwidth will be saved. By developing appropriate Lyapunov functional, sufficient conditions in matrix inequalities are established in order to achieve the stability and L2-gain of the studied systems. Then, a novel iterative algorithm is presented to solve the derived stability conditions so as to design the controllers and obtain the minimal L2-gain simultaneously. Two examples are executed at last to demonstrate the validness and benefits of our results.

Variance-Constrained Filter Design With Sensor Resolution Under Round-Robin Communication Protocol: An Outlier-Resistant Mechanism

In this article, a new outlier-resistant mechanism is proposed to deal with the variance-constrained filtering problem for a class of networked systems subject to sensor resolution under the round-robin protocol (RRP). Sensor resolution, which serves as an important index in determining measurement accuracy, is taken into account in the addressed filtering problem, and the sensor-resolution-induced uncertainty is tackled by using an upper-bounding technique. The RRP is employed to regulate the order of signal transmission in order to relieve communication overhead. In the case of measurement outliers, a tailored saturation function is dedicatedly introduced to the filter structure for the purpose of suppressing the outlier-corrupted innovations, thereby maintaining satisfactory filtering performance. By solving a matrix difference equation, an upper bound is first acquired on the error covariance of the devised filter, and the associated filter parameters are subsequently determined through minimizing the acquired bound. The validity of the developed variance-constrained filter design approach is thoroughly demonstrated via two simulation examples.

Finite-time H∞ control under the Round-Robin protocol for switched linear systems with admissible edge-dependent average dwell time

This article focuses on finite-time [Formula: see text] control under the Round-Robin protocol for switched linear systems with admissible edge-dependent average dwell time. To relieve the bandwidth pressure of the sensor, a Round-Robin protocol is constructed to decide the access rights of each node of the sensor. Under the Round-Robin protocol-based control structure, admissible edge-dependent average dwell time is applied to describe the transition relationship between the modes of the subsystem and release the restrictions of mode-dependent average dwell time. Moreover, the finite-time stability and [Formula: see text] performance of switched system with Round-Robin protocol are analyzed by using multiple Lyapunov function method combined with the admissible edge-dependent average dwell time switching. Sufficient conditions for the solution to finite-time control problem are derived which consider the [Formula: see text] performance index. Finally, the availability of the control synthesis methods is verified by the circuit model of Buck–Boost converter.

Mixed H∞ and passive resilient control for discrete-time systems with Round-Robin protocol and deception attacks

This paper focuses on the mixed [Formula: see text] and passive resilient control problem for uncertain discrete-time networked control systems subject to time delays. The measurement output is considered to be quantized by the dynamic quantizer before transmission through an unreliable communication channel, where the deception attacks may occur randomly. To further reduce the communication burden, the Round-Robin (RR) protocol is adopted to schedule sensors in a predetermined transmission order. Meanwhile, a new performance index is developed to solve restriction of the same dimension of control output and the exogenous disturbance. The S-procedure combined with a two-step uncertainties elimination method is adopted to deal with the nonlinear product terms involving multiple uncertainties. Furthermore, a decoupling method is introduced for static output feedback controller design. Sufficient conditions of the resilient controller and the dynamic quantizer are provided, which can improve the robustness of resulting closed-loop system and guarantee its stochastic stability and the specified mixed [Formula: see text] and passivity performance index. Finally, an example is given to illustrate the feasibility of the theoretical results.

Observer-based quantised control of networked systems with round-robin protocol and transmission delay

This paper addresses the ultimate boundedness control problem for a class of networked nonlinear systems with the round-robin (RR) protocol and uniform quantisation. The communication between sensor nodes and the controller is implemented via a constrained communication channel. The quantised output of the system is transmitted to the remote controller through a communication channel subject to a transmission delay. For the purpose of alleviating possible data collision, the well-known RR communication protocol is deployed to schedule the data transmissions. On the other hand, the uniform quantisation effects of the network are characterised by a round function (i.e. the nearest integer function). The purpose of the addressed problem is to design an observer-based controller for the networked nonlinear systems such that, in the presence of RR protocol and uniform quantisation effects, the closed-loop system is ultimately bounded. The controller is designed based on mean square stability analysis and Lyapunov-like method. A set of sufficient conditions for the ultimate boundedness of the closed-loop system are established and, on the basis of which, the desired controller gains are obtained by solving a set of linear matrix inequalities. The effectiveness of the proposed method is verified by numerical examples.

Secure state estimation for complex networks with multi-channel oriented round robin protocol

This paper focuses on the secure state estimation problem for complex networks (CNs) which are compromised by deception attack and constrained with limited communication resource. Firstly, a multi-channel oriented round robin (RR) protocol is proposed to schedule the data transferred over the communication network consisting of multiple transmission channels. The extended RR protocol can not only avoid the data collision caused by limited communication resource, but also fully utilize the sliced network bandwidth. Then, a state estimation error model is constructed by further considering the influence of deception attack. Following the model, efficient state estimators are designed based on analyzing the sufficient conditions that assuring the stability of the formulated state estimation error system. Finally, numerical results are presented to validate the theoretical outcomes.

Distributed fusion filtering for cyber-physical systems under Round-Robin protocol: a mixed H 2/H ∞ framework

ABSTRACT In this paper, the distributed mixed fusion filter design problem is investigated for a class of cyber-physical systems subject to non-ideal measurements under Round-Robin protocol. To save the limited communication resources, the Round-Robin protocol is employed to schedule the data transmissions from the sensors to the remote filters. The measurement is imperfect by taking into account the noises, the random saturations, nonlinearity perturbations and packet dropouts. The objective of this study is to propose a desired fusion filtering method that ensures the prescribed performance constraints on both the local and fusion filtering error dynamics. With the aid of Lyapunov function and stochastic analysis technique, a sufficient condition is established to guarantee the mixed / performance index for the local filtering error systems, and then the filter parameter matrices are derived by resorting to the solutions to some matrix inequalities. Subsequently, on the basis of the obtained local state estimates, the proper fusion parameters are acquired by solving a convex optimisation problem. Finally, a numerical example is provided to demonstrate the effectiveness of the designed fusion filter.

Secure and asynchronous filtering for piecewise homogeneous Markov jump systems with quantization and round-Robin communication

This paper investigates the problem of secure and asynchronous filtering for a class of piecewise homogeneous Markov jump systems. The transition probability in the systems is time-varying and dependent on a higher-level Markov Chain. In addition to quantization, the Round-Robin protocol, by which the sensor nodes are allowed to gain access to the network in a fixed order, is taken into account for bandwidth saving. It is assumed that deception attacks exist in the communication channels of the network, and are unknown but energy bounded. With the help of a hidden Markov model, an asynchronous filtering system is established. Then, a filter is designed such that the filtering error dynamics is mean square stable with a prescribed H∞ performance index. Two examples are given to demonstrate the effectiveness of the new design method developed.

Tracking Control Under Round-Robin Scheduling: Handling Impulsive Transmission Outliers.

In this article, the tracking control problem is investigated for a type of linear networked systems subject to the round-Robin (RR) protocol scheduling and impulsive transmission outliers (ITOs). The communication between the controller and sensors is implemented through a shared network, on which the signal transmissions are scheduled by the RR protocol. The considered ITOs are modeled by a sequence of impulsive signals whose amplitudes (i.e., the norms of all impulsive signals) and interval lengths (i.e., the duration between all adjacent impulsive signals) are greater than two known thresholds, respectively. The occurrence moment for each ITO is first examined by using a certain outlier detection approach, and then a novel parameter-dependent tracking controller is proposed to protect the tracking performance from ITOs by removing the "harmful" signals (i.e., the transmitted signals contaminated by ITOs). Sufficient conditions are presented to ensure the exponentially ultimate boundedness of the resulted tracking error, and the controller gain matrices are subsequently designed by solving a constrained optimization problem. Finally, a simulation example is provided to demonstrate the effectiveness of our developed outlier-resistant tracking control scheme.

Fuzzy H∞ robust control for T-S aero-engine systems with network-induced factors under round-robin-like protocol

Communication behavior characterization, signal scheduling and robust control are the main challenges for networked control applications in aero-engine. To address these difficulties, this paper proposes a synthesis and analysis scheme for Takagi–Sugeno (T-S) aero-engine systems subject to scheduling strategies and network-induced factors, in which the multi-node round-robin protocol (MN-RRP) is introduced to coordinate communication resources. Considering the effects of time delay and packet loss, the whole signal transmission model is established to describe the nonlinear characteristics of aero-engine networked systems. Then, a novel H∞ fuzzy proportional-integral-derivative-like (PID-like) controller is developed to improve the response performance without sacrificing robustness. Sequentially, the stability conditions are derived in terms of the token-dependent Lyapunov function. Moreover, an optimization algorithm is designed to intelligently solve the controller parameters, which allows the user to flexibly adjust performance requirements. The numerical simulations show that the designed synthesis scheme has good robustness to flight envelope changes and incomplete signals, and ensures that the controlled aero-engine system achieves rapid response, disturbance suppression and considerable tracking performance simultaneously.

Protocol-based zonotopic state and fault estimation for communication-constrained industrial cyber-physical systems

This paper is concerned with the communication protocol-based zonotopic state and fault estimation issue for a class of discrete time-varying industrial cyber-physical systems under bounded disturbances and constrained communication resources. First, in order to alleviate resource consumption, a round-robin protocol is developed to schedule the data transmission between the local sensor and the remote estimator. Second, a zonotopic set-membership estimation algorithm is developed to guarantee that the unavailable system state and fault signals could be simultaneously estimated and enclosed in a zonotope at every instant of time. Subsequently, the size of such a zonotope is minimized at each iteration by appropriately selecting a correlation matrix. Furthermore, the rigorous stability and performance analysis for the developed zonotopic estimation algorithm is provided. Finally, two simulation examples are provided to verify the obtained theoretical results.

State Estimation for Discrete Time-Delayed Impulsive Neural Networks Under Communication Constraints: A Delay-Range-Dependent Approach.

In this article, a delay-range-dependent approach is put forward to tackle the state estimation problem for delayed impulsive neural networks. A new type of nonlinear function, which is more general than the normal sigmoid function and functions constrained by the Lipschitz condition, is adopted as the neuron activation function. To effectively alleviate data collisions and save energy, the round-robin protocol is utilized to mitigate the occurrence of unnecessary network congestion in communication channels from sensors to the estimator. With the aid of the Lyapunov stability theory, a state observer is constructed such that the estimation error dynamics are asymptotically stable. The observer existence is ensured by resorting to a set of delay-range-dependent criteria which is dependent on both the impulsive time instant and a coefficient matrix. In addition, the synthesis of the observer is discussed by using linear matrix inequalities. Simulations are provided to illustrate the reasonability of our delay-range-dependent estimation approach.

Finite-Horizon ${l}_{2}-{l}_{\infty}$ State Estimation for Networked Systems Under Mixed Protocols

Dear Editor, This letter is concerned with the finite-horizon <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$l_{2}-l_{\infty}$</tex> state estimation (SE) problem for a class of networked time-delay systems where the measurements are transmitted through two individual communication channels. With the aim of preventing the transmitted data from conflicts, the signal transmissions over such the communication channels are scheduled by different communication protocols, namely the stochastic communication protocol (SCP) and Round-Robin protocol (RRP). A mixed scheduling model is proposed to describe the transmission behaviors subject to such two protocols. The objective of this letter is to design an estimator such that the estimation error achieves the desired finite-horizon <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$l_{2}-l_{\infty}$</tex> performance in the mean square. By using the Lyapunov stability theory, a sufficient condition is proposed to guarantee the existence of the desired estimator. An illustrative simulation example is given to verify the effectiveness and correctness of the proposed design scheme.

$\mathcal {H}_{\infty }$ State Estimation for PDT-Switched Coupled Neural Networks Under Round-Robin Protocol: A Cooperation-Competition-Based Mechanism

This paper is concentrated on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathcal {H_{\infty }}$</tex-math></inline-formula> state estimation problem for switched coupled neural networks based on a Takagi-Sugeno fuzzy model. Notably, the time-variant network topology with alternate fast switchings and slow ones is described suitably by a persistent dwell-time rule, and the interactive dynamics with both cooperative properties and antagonistic ones among nodes are featured comprehensively by the switching signed graph. In view of the communication pressures brought by network-induced problems and the requirements in digital control, the round-robin protocol and logarithmic quantization are flexibly integrated for more transmission efficiency and fewer data collisions. Thereafter, by utilizing a relaxed multiple Lyapunov function method and some novel matrix process techniques, sufficient criteria guaranteeing the exponential stability in a globally uniform sense with a prescribed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathcal {H_{\infty }}$</tex-math></inline-formula> performance level of the estimation error system are established. Finally, the synthesized analysis of the proposed method is presented with an illustrative example.

Protocol-Based Optimal Stealthy Data-Injection Attacks via Compromised Sensors in Cyber-Physical Systems

This article concentrates on designing a strictly stealthy attack strategy from the adversarial perspective against the multisensor cyber-physical systems (CPSs) under the round-robin protocol (RRP). The aim is to maximize the attack performance and remain strictly stealthy at the same time. Different from the existing attacks against the single-sensor application scenario, we propose a stealthy attack strategy for multisensor networked systems. In addition, due to the scheduling effects of the RRP, only incomplete transmitted data can be corrupted at each time step. Thus, a novel protocol-based attack model is developed, and then the corrupted error covariance at the remote side is derived to quantify the attack performance. Next, a convex optimization problem is formulated to solve the optimal attack parameters, which leads to the worst filtering performance. Moreover, the analytical expression of the optimal attack parameters is presented and proved. Finally, the experiments on a permanent magnet synchronous machine monitoring system are conducted to verify our results.

Adaptive Neural State Estimation of Markov Jump Systems Under Scheduling Protocols and Probabilistic Deception Attacks.

The neural-network (NN)-based state estimation issue of Markov jump systems (MJSs) subject to communication protocols and deception attacks is addressed in this article. For relieving communication burden and preventing possible data collisions, two types of scheduling protocols, namely: 1) the Round-Robin (RR) protocol and 2) weighted try-once-discard (WTOD) protocol, are applied, respectively, to coordinate the transmission sequence. In addition, considering that the communication channel may suffer from mode-dependent probabilistic deception attacks, a hidden Markov-like model is proposed to characterize the relationship between the malicious signal and system mode. Then, a novel adaptive neural state estimator is presented to reconstruct the system states. By taking the influence of deception attacks into performance analysis, sufficient conditions under two different scheduling protocols are derived, respectively, so as to ensure the ultimately boundedness of the estimate error. In the end, simulation results testify the correctness of the adaptive neural estimator design method proposed in this article.

Joint actuator fault estimation and localization under Round-Robin protocol for wheeled mobile robot

In this paper, the joint actuator fault estimation (AFE) and the wheeled mobile robot (WMR) localization under the Round-Robin protocol (RRP) problems are concerned. In order to complete the joint AFE and the WMR localization, a nominal joint system is constructed, which consists of the drive subsystem and WMR localization subsystem. In the drive subsystem of the WMR, the DC motor is used as an actuator to drive the WMR. When the faults occur, the performance of the actuator will be degraded, and the mobility of the WMR will be affected. In order to maintain a satisfactory mobility of the WMR, the faults need to be estimated timely such that some appropriate decisions or remedies can be made. In the WMR localization subsystem, for saving the network resources, the RRP is introduced to schedule the transmission of sensor measurements used for the WMR localization. The purpose of this paper is, by designing a time-varying filter for the constructed joint nominal system, to ensure the filtering error to meet the given [Formula: see text] performance requirement, such that the joint AFE and the WMR localization can be achieved simultaneously. Specifically, the sufficient condition is derived first and then the desired filter gain is designed by the recursive linear matrix inequality technology. Finally, a simulation experiment is conducted to certify the usefulness of the proposed algorithm.

Measurement outlier-resistant mobile robot localization using multiple Doppler-azimuth radars under round-robin protocol

This paper is concerned with the measurement outlier-resistant mobile robot localization problem by using multiple Doppler-azimuth radars under round-robin protocol (R-RP). In the considered robot localization system, multiple Doppler-azimuth radars are equipped on the robot platform to produce the measurement including the Doppler frequency shift and the azimuth. In order to assuage communication link congestion, the R-RP is used. For mitigating the influence of outliers, a time-varying state estimator is constructed which contains a saturation function with variable saturation levels. This paper aims at seeking out a practicable yet effective solution to the addressed robot localization problem by devising the constructed estimator which can assure that, over a finite horizon, the localization error satisfies the given H∞ performance index. By constructing an appropriate Lyapunov function, the sufficient condition, which can guarantee the localization error to fulfill the given H∞ performance, is established. Then, by resorting to the solution to a set of linear matrix inequalities, the constructed estimator can be devised. In the light of the estimator design strategy proposed in this paper, the corresponding robot localization algorithm is developed. At last, some simulations are conducted to testify the usefulness of the developed robot localization algorithm.