Round-Robin Protocol Research Articles

Model Predictive Control for Interval Type-2 T-S Fuzzy Systems Under Round-Robin Protocol

Abstract This paper is concerned with the fuzzy model predictive control (FMPC) problem for a class of interval type-2 Takagi-Sugeno (IT2 T-S) fuzzy systems under the round-robin (RR) protocol. First, the RR protocol and the IT2 T-S fuzzy nonlinearities are established in a unified representation, which generates a novel networked IT2 T-S system. Second, a token-dependent quadratic function and the corresponding “min-max” optimization problem are formulated, and then an online auxiliary optimization problem is provided to find the sub-optimal feedback gains. Third, by fully considering the impact of the RR protocol and the IT2 T-S fuzzy nonlinearities, some sufficient conditions are put forward to guarantee the asymptotic stability of the underlying system. Finally, simulation results of a numerical example are provided to illustrate the effectiveness of the proposed FMPC algorithm.

Asynchronous Control for Markov Switching Lur’e Systems With Round-Robin Protocol

This paper addresses the asynchronous control design problem for discrete-time Markov switching Lur’e systems. First, to schedule the information transmission and data collisions by the limited shared channel, the round-robin protocol is adopted in scheduling the information exchange order. Second, considering that the system mode cannot be identified to controller, a mode observer is employed to evaluate the system mode by menas of a hidden Markov model. To address this issue, the mode-dependent stochastic Lur’e type Lyapunov functional is analyzed, and several sufficient criteria with prescribed performance are attained to guarantee the stochastically stable of the resulting discrete-time MSLSs. Finally, the effectiveness and applicability of the gained technique is verified by a practical example.

Distributed set-membership filtering for nonlinear systems subject to round-robin protocol and stochastic communication protocol over sensor networks

In this paper, the distributed set-membership filtering problem is investigated for general nonlinear systems subject to Round-Robin and stochastic communication protocols over sensor networks. The considered disturbances are assumed to be unknown but bounded within certain known ellipsoidal regions. Two types of frequently used protocols, i.e., the Round-Robin and stochastic communication protocols are adopted separately to regulate the data transmission among sensor nodes. According to the Round-Robin protocol, each node is able to receive information from only one of its neighboring nodes in a circular order at each time step, whereas the stochastic communication protocol allows each node randomly receive the information sent from one of the neighboring nodes. By resorting to the recursive linear matrix inequalities approach, sufficient conditions are established for the existence of the desired distributed filter, guaranteeing that the state estimates are constrained within certain pre-determined ellipsoidal regions at each time step. Then two optimization problems aiming to minimize the ellipsoids (in the sense of matrix trace) are put forward to seek the locally optimal filtering performance. Finally, simulation examples are given to illustrate the effectiveness of the proposed algorithms.

Resilient Set-membership State Estimation for Uncertain Complex Networks with Sensor Saturation under Round-Robin Protocol

This article gives primarily attention to the resilient set-membership state estimation problem for a class of discrete time-varying complex networks with distributed delays, uncertain inner coupling and sensor saturation under the round-robin (RR) protocol. The process and measurement noises are unknown but bounded, which are confined to the ellipsoidal sets. The RR protocol is utilized to assign the priority of accessing to the communication network to nodes in terms of a fixed circular order. By means of the recursive linear matrix inequality (RLMI) technique, a sufficient criterion is established to guarantee that the one-step ahead estimation error is confined to the ellipsoidal set. In term of the convex optimization approach and the recursive algorithm, the desired estimator gains can be derived by utilizing the sufficient condition and optimizing the corresponding constraint matrices. Finally, a simulation example is used to verify the effectiveness of the designed resilient set-membership state estimation scheme.

Moving Horizon Estimation for Networked Time-Delay Systems Under Round-Robin Protocol

This paper is concerned with the moving horizon estimation problem for a class of discrete time-delay systems under the Round-Robin (RR) protocol. The communication between the sensor nodes and the remote state estimator is implemented via a shared network, where only one sensor node is permitted to transmit data at each time instant for the purpose of preventing data collisions. The RR protocol is utilized to orchestrate the transmission order of sensor nodes, under which the selected node obtaining access to the network could be modeled by a periodic function. A lifting technology is introduced to reformulate the system model into a linear system without delays. The aim of the addressed problem is to develop a moving horizon estimator such that the estimation error is ultimately bounded. A sufficient condition is established to ensure the ultimate boundedness in terms of a matrix inequality. Within the established theoretical framework, two optimization problems are proposed to calculate the corresponding estimator parameters according to two different performance requirements (e.g., the smallest ultimate bound and the fastest decay rate). Finally, simulation examples are given to illustrate the effectiveness of the estimator design scheme.

Fault detection for discrete time-delay networked systems with round-robin protocol in finite-frequency domain

ABSTRACTThe paper considers the fault detection problem over finite-frequency domain for a class of discrete time-delayed networked systems subject to round-robin protocol. This protocol is a periodic one to schedule the information transmitted via a shared communication network with an intent to prevent the data from collisions. In this scenario, the error dynamics can be regarded as a periodic protocol-induced system. The aim of the problem addressed is to design a fault detection filter that (1) the sensitivity of the residual to the fault is enhanced by means of a maximised index and (2) the effect from the exogenous disturbances on the residual is decreased with considering a minimised index. By resorting to a Lyapunov function, an improved version of generalised Kalman–Yakubovich–Popov lemma (GKYP) is first developed for protocol-induced periodic system. Then, in light of such a lemma, sufficient conditions are derived to guarantee both the fault sensitivity and the disturbance attenuation capability by solving a set of matrix inequalities. Finally, the usefulness of the presented fault detection algorithm is utilised via a numerical simulation.

${H}_{\infty }$ Filtering for Fuzzy Jumping Genetic Regulatory Networks With Round-Robin Protocol: A Hidden-Markov-Model-Based Approach

In this article, a method to design the filter for fuzzy jumping genetic regulatory networks is explored. The case when the filters cannot directly utilize the mode information of the plant is taken into account. A hidden Markov model is introduced to address such a problem. Furthermore, a mature scheduling method, namely round-robin protocol, is employed to optimize the data transmission in genetic regulatory networks. On the basis of the fuzzy model approach and the stochastic analysis technique, some novel conditions ensuring the $H_{\infty }$ performance and stochastic stability of the error system are established. The parameters of the filter can be presented via addressing the convex optimization problem. The feasibility of results is finally illustrated by considering a repressilator model subject to stochastic jumping parameters.

Security control of cyber-physical switched systems under Round-Robin protocol: Input-to-state stability in probability

This work addresses the sliding mode control (SMC) problem for a class of cyber-physical switched systems, in which both the Round-Robin (RR) protocol scheduling and the deception attacks may happen on the controller-to-actuator (C/A) channels. Under the regulation of RR protocol, only one controller node at each instant can access the network and transmit its signal to the corresponding actuator node, that is, the other actuators cannot obtain any new control information. Especially, the transmitted signal could be contaminated by randomly injecting false data. Thus, a key problem is how to design a suitable sliding surface and a desirable sliding mode controller for guaranteeing the dynamic performance of the closed-loop switched systems. To this end, a compensation strategy is proposed for those actuator nodes that don’t receive any new control signals at certain instant, based which a token-dependent SMC law is designed. Besides, the method of input-to-state stability in probability (ISSiP) is introduced and the sufficient conditions are established for the reachability of the specified sliding surface and the ISSiP of the resultant switched systems. Finally, some numerical simulation results are provided.

Distributed State-Saturated Recursive Filtering Over Sensor Networks Under Round-Robin Protocol.

This article is concerned with the distributed recursive filtering issue for stochastic discrete time-varying systems subjected to both state saturations and round-robin (RR) protocols over sensor networks. The phenomenon of state saturation is considered to better describe practical engineering. The RR protocol is introduced to mitigate a network burden by determining which component of the sensor node has access to the network at each transmission instant. The purpose of the issue under consideration is to construct a distributed recursive filter such that a certain filtering error covariance's upper bound can be found and the corresponding filter parameters' explicit expression is given with both state saturations and RR protocols. By taking advantage of matrix difference equations, a filtering error covariance's upper bound can be presented and then be minimized by appropriately designing filter parameters. In particular, by using a matrix simplification technique, the sensor network topology's sparseness issue can be tackled. Finally, the feasibility for the addressed filtering scheme is demonstrated by an example.

Protocol-Based Unscented Kalman Filtering in the Presence of Stochastic Uncertainties

In this paper, the unscented Kalman filtering (UKF) problem is investigated for a class of general nonlinear systems with stochastic uncertainties under communication protocols. A modified unscented transformation is put forward to account for stochastic uncertainties caused by modeling errors. For preventing data collisions and mitigating communication burden, the round-robin protocol and the weighted try-once-discard protocol are, respectively, introduced to regulate the data transmission order from sensors to the filter. Then, by employing two kinds of data-holding strategies (i.e., zero-order holder and zero input) for those nodes without transmission privilege, two novel protocol-based measurement models are formulated. Subsequently, by resorting to the sigma point approximation method, two resource-saving UKF algorithms are developed, where the impact from the underlying protocols on the filter design is explicitly quantified. Finally, compared with the protocol-based extended Kalman filtering algorithms, a simulation example is presented to demonstrate the effectiveness of the proposed protocol-based UKF algorithms.

Finite-horizon distributed H∞-consensus control of time-varying multi-agent systems with Round-Robin protocol

This paper takes into account the H∞-consensus control problem for a class of uncertain discrete time-varying multi-agent systems which is constrained by Round-Robin scheduling protocol and measurement saturations. In the multi-agent system under consideration, all the system parameters are time-varying to better reflect the practical engineering. The Round-Robin protocol is utilized to alleviate the communication congestion in a shared constrained network by scheduling the information transmission among agents, where an agent can receive one neighbor’s information at each time instant and the transmission order of neighboring agents is regulated. The aim of the research is to design consensus controller for each agent over an assigned finite horizon such that the closed-loop multi-agent systems with saturated measurement outputs can satisfy the H∞ disturbance attenuation level. Next, a sufficient condition is derived to ensure the H∞-consensus performance constraint based on the Lyapunov stability theory. Then, the controller parameters can be obtained by solving recursively a linear matrix inequality at every time instant. Finally, a numerical example is provided to show the effectiveness of the developed consensus control scheme.

Full Information Estimation for Time-Varying Systems Subject to Round-Robin Scheduling: A Recursive Filter Approach

The full information estimation (FIE) problem is addressed for discrete time-varying systems (TVSs) subject to the effects of a round-Robin (RR) protocol. A shared communication network is adopted for data transmissions between sensor nodes and the state estimator. In order to avoid data collisions in signal transmission, only one sensor node could have access to the network and communicate with the state estimator per time instant. The so-called RR protocol, which is also known as the token ring protocol, is employed to orchestrate the access sequence of sensor nodes, under which the chosen sensor node communicating with the state estimator could be modeled by a periodic function. A novel recursive FIE scheme is developed by defining a modified cost function and using a so-called “backward-propagation-constraints.” The modified cost function represents a special global estimation performance. The solution of the proposed FIE scheme is achieved by solving a minimization problem. Then, the recursive manner of such a solution is studied for the purpose of online applications. For the purpose of ensuring the estimation performance, sufficient conditions are obtained to derive the upper bound of the norm of the state estimation error (SEE). Finally, two illustrative examples are proposed to demonstrate the effectiveness of the developed estimation algorithm.

H∞ state estimation for two-dimensional systems with randomly occurring uncertainties and Round-Robin protocol

In this paper, the robust H∞ state estimator is designed for the two-dimensional (2-D) systems in Fornasini-Machesini second model under logarithmic quantization and Round-Robin protocol. The norm-bounded uncertainties are also involved in the considered system, which are governed by two stochastic variables satisfying the Bernoulli distribution. As a kind of static scheduling, the Round-Robin protocol assigns the communication access rights to the sensors in the chronological order. The aim of this paper is to design a state estimator so that the addressed estimation error system satisfies a predefined H∞ performance index. Sufficient conditions are given to ensure the 2-D augmented error system to be robustly stable via intensive stochastic analysis, then the results are further extended to achieve the robust H∞ stability for the augmented error system. Explicit expressions of the estimator gains are also given by solving certain matrix inequalities. Finally, a numerical example is presented to demonstrate the effectiveness of the proposed estimation scheme.

Observer-based feedback stabilization of Lipschitz nonlinear systems in the presence of asynchronous sampling and scheduling protocols

In this paper, the network-based observation and stabilization problems for Lipschitz nonlinear systems under scheduling communication are investigated. It is assumed that the signal transmission between the sensors and the controller or between the controller and the plant is implemented through a wireless network. Moreover, the scheduling of the sensed signal towards the controller is ruled by the Round-Robin (RR) protocol or the i.i.d. stochastic protocol. A general framework for observer-based feedback stabilization is proposed in which the control input is generated by a zero-order device which stores the sampled output of the sample-and-hold Luenberger observer-based controller. The resulting closed-loop system is modeled as a cascaded hybrid system with partial state subject to impulsive perturbation. Sufficient conditions for the existence of sample-and-hold Luenberger observer-based sampled-data controllers are derived by applying separation principle and time-dependent Lyapunov functionals. These conditions allow to design observers and controllers separately. A numerical example is presented to illustrate the effectiveness of the developed methodology.

Noncooperative Event-Triggered Control Strategy Design With Round-Robin Protocol: Applications to Load Frequency Control of Circuit Systems

In this paper, the noncooperative optimal control problem is investigated for a class of discrete time-varying networked control systems subject to exogenous nonlinear disturbances. To relive the transmission burden in the sensor-to-controller channel, the Round-Robin protocol is adopted to schedule the sensor transmissions. On the other hand, the controller operates in an event-triggered manner so as to reduce the transmission frequency and thereby preserving the energy in the controller-to-actuator channel. In the presence of the underlying scheduling and triggering mechanism, it is literally impossible to acquire the accurate value of the individual cost function for each controller and, as an effective alternative, a certain upper bound is derived on the individual cost function. Then, in virtue of the completing-the-square technique and the Moore–Penrose pseudo inverse, such an upper bound is minimized at each time instant. Furthermore, a sufficient condition is established to guarantee the boundedness of the derived upper bound over the infinite horizon. Finally, a numerical example on the power grid is provided to verify the validity of the proposed methodology.

Networked recursive filtering for time-delayed nonlinear stochastic systems with uniform quantisation under Round-Robin protocol

In this paper, the design of networked recursive filter is investigated for a kind of nonlinear stochastic systems subject to missing measurements, fixed time-delay and uniform quantisation under the Round-Robin protocol. In a digital platform, the information coming from multi-sensors could be subject to missing measurements due to the environment effect and then need to be transformed into digital signals via uniform quantizers. In addition, the Round-Robin protocol is adopted to govern the token accessing to channel media so as to both save energy and mitigate the data congestion. A novel extended Kalman-type recursive filter is constructed that firstly combines the Round-Robin protocol, namely, in the form of the augmentation of the plant system dynamics and the protocol-induced periodic measurements. In the simultaneous consideration of system delays, missing measurements, uniform quantisation, as well as the Round-Robin protocol, the purpose for the discussed filtering problem is to obtain a set of filter parameters over a finite-horizon to minimise the upper bound of filtering error covariance as far as possible. Via elaborate mathematical analysis, the desired filter parameter is obtained by virtue of solving two Riccati-type optimisation equations, which are dependent on the latest estimation states. The genetic algorithm has been introduced to optimise the dynamic parameter selections. In addition, it is revealed in theory that the trace of the upper bound of filtering error covariance is non-decreasing as the quantisation level increases. Finally, the effectiveness of the proposed design scheme is inspected by a discretised maneuvering target tracking system.

Distributed Secure Filtering for Discrete-Time Systems Under Round-Robin Protocol and Deception Attacks.

This paper addresses the problem of designing a distributed filter for linear discrete-time networked control systems that suffer from randomly occurring deception attacks and bounded disturbances. A Round-Robin-type protocol is applied to schedule communication between filters due to the communication resource constraint. The discrete-time Wirtinger's inequality is used to derive a sufficient condition that ensures H∞ performance of the closed-loop system. A corresponding filter that guarantees the security is designed. Finally, a numerical example of an inverted pendulum system is provided to demonstrate the feasibility of the proposed filter.

Robust model predictive control for polytopic uncertain systems with state saturation nonlinearities under Round‐Robin protocol

SummaryThis paper is concerned with the robust model predictive control (RMPC) problem for polytopic uncertain systems with state saturation nonlinearities under the Round‐Robin (RR) protocol. With respect to the practical application, one of the most commonly encountered obstacles that stem from the physical limitation of system components, ie, state saturation, is adequately taken into consideration. In order to reduce the network transmission burden and improve the utilization of the network from the controller nodes to the actuator node, a so‐called RR protocol is employed to orchestrate the data transmission order. At each transmission instant, only one controller node that obtains the priority is accessible to the shared communication network. Our aim of the underlying problem is to design a set of controllers in the framework of RMPC such that the closed‐loop system is asymptotically stable. By taking the influence of the RR protocol and the state saturation precisely into account, some sufficient criteria are established in terms of the token‐dependent Lyapunov‐like approach. Then, an online optimization problem subjected to some matrix inequality constraints is provided, and the desired controllers can be obtained by solving the certain upper bound of the objective addressed. Finally, a distillation process example is provided to illustrate the effectiveness of the proposed RMPC approach.

Distributed filtering for time-varying systems over sensor networks with randomly switching topologies under the Round-Robin protocol

This paper focuses on the filtering problem for nonlinear systems over sensor networks whose topologies are changeable subject to Round-Robin (RR) protocol in the finite horizon case. The phenomenon of switching topologies for sensor networks is considered due to the weak connections between the node and its neighbors. The Round-Robin communication strategy is employed to save the limited bandwidth and reduce the network resource consumption. It is our target to design distributed filters so that the dynamics of augmented error system satisfies the given level of average H∞ performance. We get the sufficient conditions in order to guarantee the existence of the desired distributed filters whose parameter matrices would be attained by a recursive method in terms of a set of matrix inequalities. In the end, a numerical simulation is exploited to describe the validity of the raised filter design technique.

Fault diagnosis for time-varying systems with multiplicative noises over sensor networks subject to Round-Robin protocol

In this paper, the fault diagnosis problem is investigated for time-varying systems with multiplicative noises over sensor networks. The system model is subject to state- and control-dependent noises, and the Round-Robin protocol is applied in sensor networks to prevent data collisions. By means of the least-squares approach, a series of fault estimation filters are designed for the addressed system, and each filter can estimate the augmented state which includes system state and a fault signal. According to residual signals, several evaluation functions are derived and one of them is selected for the purpose of fault detection. By employing the residual matching method, the filter with least evaluation function can be used to isolate and estimate the occurred fault. A numerical example is provided to demonstrate the effectiveness of our proposed fault diagnosis scheme.