Event-triggered Output Feedback Research Articles

Minimum-Time and Minimum-Triggering Observability of Stochastic Boolean Networks

This article investigates the observability of Markovian jump Boolean networks (MJBNs) via algebraic state space representation approach. A necessary and sufficient criterion in the form of linear programming is derived for the asymptotic observability in distribution of MJBNs, and several conditions are obtained for the finite-time observability based on the properties of nilpotent matrices. Subsequently, in order to minimize the time consumption, a maximum principle is established to address the minimum-time observability problem. With regard to the event-triggered output feedback observability, an efficient procedure is developed to minimize the number of triggering events. Finally, three numerical examples are employed to demonstrate the effectiveness of theoretical results.

Fuzzy-Approximation-Based Event-Triggered Output Feedback Adaptive Control for Nonlinear Switched Large-Scale Systems With Actuator Faults

This article investigates the output feedback adaptive fuzzy event-triggered fault-tolerant control issue of nonlinear switched large-scale systems. First, a new state observer is established to estimate unmeasured states. Fuzzy logic systems are exploited to identify both unknown interconnections and uncertainties. Next, the Nussbaum gain technique is employed to tackle actuator failures and unknown control directions. A novel adaptive fuzzy fault-tolerant event-triggered controller is derived to guarantee the boundedness of closed-loop signals. Moreover, the Zeno phenomenon can be avoided. Finally, a practical simulation is given to illustrate the validity of the developed method.

Dynamic event-triggered output feedback control for stochastic nonlinear systems

Abstract In this paper, the event-triggered stabilization problem for stochastic nonlinear systems is addressed. A dynamic event-triggered transmission strategy is proposed for general stochastic nonlinear systems without the linear growth assumption and the proposed transmission strategy can be applied to the output-based dynamic controller. Zeno phenomenon is avoided in the transmission strategy. The resulted closed-loop system is modeled into a stochastic hybrid system. Uniformly globally asymptotic stability in probability is concluded by showing that the equilibrium set is uniformly globally stable in probability and arbitrarily small neighborhood of the equilibrium set is uniformly globally recurrent in probability.

Dynamic Event-Triggered Tracking Control for a Class of p-Normal Nonlinear Systems

This paper investigates the problem of dynamic event-triggered output feedback tracking control for a class of p-normal nonlinear systems with unknown growth rate. To cope with the unknown growth rate imposed on the system nonlinearities, a dynamic gain technique is introduced and a constructive coordinate transformation is given. On the other hand, an event-triggered strategy combining with the dynamic gain is proposed such that the triggering threshold can be adjusted in an adaptive manner. With the help of the proposed event-triggered strategy, a dynamic event-based output feedback controller is developed to ensure that all signals of the closed-loop system are bounded while the tracking error converges to a small neighborhood of the origin. Moreover, it is proved that the Zeno behavior is excluded in the presence of nonsmooth controller. Two examples, including an induction heater circuit system and a numerical example, are provided to indicate the effectiveness of the proposed control method.

Event-Triggered Output Feedback Synchronization of Master-Slave Neural Networks Under Deception Attacks.

The problem of event-triggered synchronization of master-slave neural networks is investigated in this article. It is assumed that both communication channels from the sensor to controller and from controller to actuator are subject to stochastic deception attacks modeled by two independent Markov processes. Two discrete event-triggered mechanisms are introduced for both channels to reduce the number of data transmission through the communication channels. To comply with practical point of view, static output feedback is utilized. By employing the Lyapunov-Krasovskii functional method, some sufficient conditions on the synchronization of master-slave neural networks are derived in terms of linear matrix inequalities, which make it easy to design suitable output feedback controllers. Finally, a numerical example is presented to show the effectiveness of the proposed method.

Neural-Network Approximation-Based Adaptive Periodic Event-Triggered Output-Feedback Control of Switched Nonlinear Systems.

This study considers an adaptive neural-network (NN) periodic event-triggered control (PETC) problem for switched nonlinear systems (SNSs). In the system, only the system output is available at sampling instants. A novel adaptive law and a state observer are constructed by using only the sampled system output. A new output-feedback adaptive NN PETC strategy is developed to reduce the usage of communication resources; it includes a controller that only uses event-sampling information and an event-triggering mechanism (ETM) that is only intermittently monitored at sampling instants. The proposed adaptive NN PETC strategy does not need restrictions on nonlinear functions reported in some previous studies. It is proven that all states of the closed-loop system (CLS) are semiglobally uniformly ultimately bounded (SGUUB) under arbitrary switchings by choosing an allowable sampling period. Finally, the proposed scheme is applied to a continuous stirred tank reactor (CSTR) system and a numerical example to verify its effectiveness.

Event-triggered robust control for quadrotors with preassigned time performance constraints

In this paper, an event-triggered robust control for quadrotors with preassigned time performance constraints is presented. In order to prolong operational time and enhance mission completion efficiency subject to limited onboard power, a switching threshold event-triggered strategy is embedded in controller-to-actuator and sensor-to-controller channels, where switching threshold event-triggered based extended state observers (SET-ESO) are respectively established in the trajectory and attitude subsystems to accomplish the real-time estimation of linear velocity, angular velocity along with lumped disturbances using intermittent measurements, and the quantitative analysis between the ultimate observation error and parameters of SET-ESO is revealed. Based on the estimation results, an event-triggered output feedback control law including a robust compensation term is established to realize an anti-disturbance time-varying trajectory tracking without involving Zeno phenomena. Moreover, to eliminate severe fluctuations at the transient inherent in traditional prescribed performance control (TPPC) with a fast convergent rate, a tracking differentiator-based prescribed performance control (TDPPC) mechanism is exploited to ensure the trajectory state converge to a pre-given region with a preassigned prescribed time, such that a smooth and pre-specified finite-time tracking capability independent of control parameters is preserved. Next, with the aid of Lyapunov synthesis, all the signals involved in the closed-loop quadrotor system are proved to be bounded, and the preassigned time performance constraints are not violated. The simulation and comparison results are shown to validate the effectiveness of the proposed control scheme.

Boundary stabilisation via event-triggered output-feedback for a class of 2 × 2 hyperbolic systems

This paper is devoted to the boundary stabilisation via event-triggered output-feedback for a class of hyperbolic systems. Different from the closely related works, the system parameters are spatially varying and only one boundary measurement is available for feedback, which brings essential difficulties to the analysis and synthesis of event-triggered control. To solve the problem, by using the time-varying strategy and the infinite-dimensional backstepping technique, a novel event-triggered output-feedback controller is designed for the systems. Particularly, a time-varying event-triggering mechanism, with an extra decaying signal introduced into the threshold, is determined. It is rigorously shown that the designed event-triggered controller can guarantee that all the states of the resulting closed-loop system exponentially converge to zero in the sense of norm while no Zeno phenomenon occurs. Two simulation examples are given to illustrate the effectiveness of the established boundary control strategy.

Design of Hybrid Event-Triggered Containment Controllers for Homogeneous and Heterogeneous Multiagent Systems.

This article is concerned with the containment control problem for a class of multiagent systems (MASs) based on event-triggered output feedback. For homogeneous MASs, a distributed observer-based containment control protocol and a distributed hybrid event-triggered scheme are proposed. The observers, containment controllers, and event-triggered conditions are designed simultaneously by means of the matrix transformation technique. The proposed event-triggered mechanism includes not only the traditional triggering function but also a running time upper bound, which saves the communication workload and improves system performance. Furthermore, based on the output regulation framework, a hybrid distributed event-triggered scheme and a distributed containment control protocol for heterogeneous MASs are developed, where the dynamics of the followers vary. Multiply unmanned aerial vehicles are modeled as a linear MAS to verify the effectiveness of the presented algorithm.

Robust Output Regulation of Linear Systems by Event-Triggered Dynamic Output Feedback Control

In this article, we study the robust output regulation problem of linear systems by an event-triggered output feedback control law. We first summarize the solvability of the linear robust output regulation problem by the internal model design. Then, we implement this continuous-time control law by an event-triggered output feedback control law together with an output-based triggering mechanism. We show that, under almost the same solvability conditions as those for the linear robust output regulation problem, the robust output regulation problem can also be solved by an event-triggered output feedback control law without incurring Zeno phenomenon. Furthermore, we show that, it is possible to solve the robust output regulation problem practically while preventing the interevent time from approaching zero as time tends to infinity.

Event-triggered output feedback control for discrete Markov jump systems under deception attack

An event-triggered dynamic output feedback control (DOFC) problem for discrete Markov jump systems is considered, where both measurement and control channel are under the deception attacks. To reduce the data traffic in the channel and the control actions against attack, two event-triggered schemes (ETSs) are implemented on sensor and controller node asynchronously. And two quantizers are installed independently. Sufficient criterions for ensuring asymptotic stability of the networked control systems (NCSs) are obtained by deriving the Lyapunov functional, and the co-design of DOFC with ETSs can be acquired in terms of the linear matrix inequality (LMI). An application on DC motor is utilized to prove the feasibility of this method.

Event‐triggered practical finite‐time output feedback stabilisation for switched non‐linear time‐delay systems

This study investigates the event-triggered practical finite-time output feedback control for a class of switched high-order non-linear time-delay systems with uncertain control coefficients. A reduced-order observer is first constructed to estimate the unmeasurable states. By adding a power integrator technique, an event-triggered output feedback controller is designed for the nominal system. Subsequently, the constructed observer and controller are scaled with a suitable gain by homogeneous domination approach, which, together with an appropriate Lyapunov–Krasoviskii functional, can render that the uncertain switched high-order non-linear system with time-varying delay is practical finite-time stability. Finally, two examples are provided to demonstrate the validity of the proposed scheme.

A Switching Method to Event-Triggered Output Feedback Control for Unmanned Aerial Vehicles Over Cognitive Radio Networks

This article investigates the event-triggered output feedback control problem for unmanned aerial vehicle (UAV) systems over cognitive radio (CR) networks. A periodic event-triggered scheme is proposed in the presence of CR networks. By modeling the CR network as an <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> – <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> switch, a new switched time-delay system model is developed for the event-triggered UAV. Based on the new model, the exponential stability and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$H_{\infty }$ </tex-math></inline-formula> performance criteria are derived by using the constructed Lyapunov function. Then, a co-design method is proposed to obtain mode-dependent controller gains and trigger parameters simultaneously. Finally, the proposed scheme is verified by a UAV system.

Event-triggered Output Feedback Resilient Control for NCSs under Deception Attacks

This paper studies event-triggered output feedback resilient control for networked control systems (NCSs) under stochastic deception attacks following a Bernoulli distribution. Unlike continuous event-triggered mechanism (ETM) requiring dedicated hardware and complex Zeno-avoidance computation, an output-based discrete ETM is firstly introduced, which overcomes limits of continuous ETM and relaxes state-available constraint. Secondly, a novel time-delay system model is established, which makes it possible to study effects of the ETM, stochastic attacks and network-induced delays in a unified framework. Thirdly, less-conservative asymptotic stability criteria with desired H∞ index are obtained, which derive quantitative relationships among the ETM, stochastic attacks, network delays, plant and resilient controller. Further, sufficient conditions to co-deign the ETM and resilient controller are presented. Finally, examples confirm effectiveness of the proposed method.

Distributed Bipartite Consensus of Linear Multiagent Systems Based on Event-Triggered Output Feedback Control Scheme

This article investigates the bipartite consensus problem for linear multiagent systems by the event-triggered output feedback control scheme. Both cooperative interaction and antagonistic interaction between neighbor agents are considered. Assuming that the system states are not available for measurement, the state observer is thus proposed to settle this scenario. Then, a novel observer-based bipartite control scheme is developed on the basis of two event-triggering mechanisms. One is designed for the communication between neighbors and another is for controller updates. Different from the existing methods, the proposed control strategy does not need continuous updates, avoids continuous communication between neighbors, and is applicable for the signed communication topology. Moreover, we extend the results from the bipartite leaderless consensus to the bipartite leader-following consensus and the bipartite containment consensus. It is proven that the proposed controllers fulfill the exclusion of Zeno behavior in three consensus problems. Finally, three examples are provided to illustrate the feasibility of the theoretical results.

Event-triggered controller via adaptive output-feedback for a class of uncertain nonlinear systems

This paper addresses the global stabilisation via adaptive event-triggered output-feedback for a class of uncertain nonlinear systems. Remarkably, the systems under investigation simultaneously allow large uncertainties and linearly unmeasured states dependent growth for the first time in the event-triggered framework, for which a dynamic high gain and an observer based on the high gain are introduced. By integrating compensation and time-varying strategies, an adaptive event-triggered output-feedback controller is established. Particularly, a new event-triggering mechanism is introduced, in which the time-varying threshold (strictly positive and gradually decaying) is key to ensure the validity of the event-triggered controller and achieve the convergence. A simulation example is given to illustrate the effectiveness of the proposed approach.

Event-Triggered Output Feedback Control for MEMS Gyroscope With Prescribed Performance

This paper investigates an event-triggered output feedback control problem with guaranteed tracking performance for microelectromechanical system (MEMS) gyroscope subject to the lumped disturbances, including parameter uncertainties, coupling between driving mode and sensing mode, and unknown external disturbances. Firstly, to make the system output tracking errors evolve within the predetermined performance envelopes, a prescribed performance control (PPC) is employed in our controller design, such that a prescribed trajectory tracking with preselected settling time and steady-state tracking accuracy can be ensured. Besides, to simultaneously realize disturbance rejection and estimation of the immeasurable velocity state, linear extended state observers (LESOs) are designed to reconstruct the lumped disturbances and immeasurable velocity states for both MEMS gyroscope driving and sensing modes. In general, excessively energy and resource consumption are fundamentally neglected in most of the existing output feedback controllers for MEMS gyroscope, which will dramatically reduce the operational time of the close-loop system. To address this problem, we embed a fixed threshold event-triggered mechanism into the controller design procedure, such that the communication data size can be drastically reduced without sacrificing the tracking accuracy. Finally, to obtain the close-loop stability for MEMS gyroscope, robust control laws are designed to compensate for the measurement error and estimation error, meanwhile Zeno phenomena can be effectively eliminated. The simulation results and comparisons validate the effectiveness of the proposed scheme.

Observer-based event-triggered output feedback control for fractional-order cyber–physical systems subject to stochastic network attacks

This paper is engaged in investigating the observer-based event-triggered output feedback control issue for fractional-order cyber–physical systems with stochastic network attacks, where the order scale of the fractional derivative used is 0<α<1. An event-triggered scheme (ETS) with output-independent threshold is proposed to renew the observer input so as to reduce the redundant data communications. Considering the effects of the ETS and network attacks, a novel closed-loop fractional-order control system model is constructed. By making use of fractional-order Lyapunov indirect approach, sufficient conditions that can insure the global stochastic asymptotic stability of the established closed-loop control system are obtained. Moreover, according to the singular value decomposition (SVD) of matrix, the co-design of the gains of the desired observer and controller is addressed by finding the solution of the linear matrix inequalities (LMIs). Finally, a numerical example and a diesel engine control system are provided to validate the feasibility of the adopted observer-based control method.

Periodic Event-Triggered Output-Feedback Stabilization for Stochastic Systems.

This article is devoted to explore the periodic event-triggered stabilization for continuous-time stochastic systems, and to develop analysis tools/methods for stochastic periodic event-triggered control. Notably, without real-time monitoring of system behavior as in the scenario with continuous event evaluation, it is critical to delicately estimate and govern the execution/sampling error to achieve the desired system performance. This, under stochastic effects, would be substantially challenging, since the behavior of the stochastic system is hard to predict and is disparate between trials even with the same initial conditions. In this article, a framework of global stabilization via periodic event-triggered output-feedback is established: 1) a criterion condition based on the ISS-Lyapunov function is presented for the feasibility of the desired event-triggered stabilization; 2) both the asymptotic stabilization and exponential stabilization are achieved for the systems, with delicately specifying the periodic event-triggering mechanism; and 3) the involved analysis, without applying the well-known Lyapunov theorems, can serve as a pattern from estimating sampling and execution errors to assess the closed-loop stability for stochastic periodic event-triggered control. Moreover, based on the established framework, we contribute the stabilizing controller design via periodic event-triggered output-feedback for a class of stochastic nonlinear systems.

Adaptive Event-Triggered Output Feedback Fuzzy Control for Nonlinear Networked Systems With Packet Dropouts and Actuator Failure

This paper studies the problem of adaptive eventtriggered dynamic output feedback fuzzy control for nonlinear networked control systems. Two crucial factors, packet dropouts and actuator failure, are taken into consideration simultaneously. Takagi-Sugeno fuzzy model is introduced to describe considered systems. The Bernoulli random distribution process is employed to depict the phenomenon of data missing. The actuator failure model is adopted to depict actuator failure. An innovative adaptive event-triggered strategy is built to save computational resource. In the light of Lyapunov stability theory, a fuzzy dynamic output feedback controller is designed to guarantee the stochastic stability and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance for considered systems. Finally, simulation results are provided to demonstrate the usefulness of the proposed control strategy.