Event-triggered Output Regulation Research Articles

Rolling Detection Event-Triggered Output Regulation for Switched Interval Type-2 Fuzzy Systems Against Data Integrity and Derivative Injection Attacks

Rolling Detection Event-Triggered Output Regulation for Switched Interval Type-2 Fuzzy Systems Against Data Integrity and Derivative Injection Attacks

Mixed Event-Triggered Output Regulation for Networked Switched Systems With Unstable Switching Dynamics Under Long-Duration DoS Attacks.

In this article, the event-triggered output regulation problem (EORP) under the denial-of-service (DoS) attacks is considered for networked switched systems (NSSs) with unstable switching dynamics (USDs). The USDs here refer to the unsolvable output regulation of each subsystem and the destabilization at partial switching instants, which indicates that the Lyapunov function does not decrease monotonically in activation intervals of each subsystem and increases at partial switching instants. First, long-duration DoS attacks (LDDAs) are considered, where LDDAs imply that their duration may be longer than the total dwell time (DT) of several adjacent activated subsystems. By imposing constraints at switching instants, consecutive asynchronous subsystem switching caused by LDDAs and USDs is allowed, that is, the subsystem switches several times but the controller switching is blocked by LDDAs and controllers fail to switch correspondingly. Second, mixed event-triggered mechanisms (ETMs), combining event-triggered conditions and periodic sampling conditions, are designed to reduce network burden under LDDAs and improve system performance subject to destabilizing switching. Then, an improved DT for switching signal permits irregular arrangement of destabilizing and stabilizing switching and is more suitable for NSSs subject to LDDAs. Moreover, sufficient conditions ensure the solvability of EORP for NSSs with USDs under LDDAs, network-induced delays, random packet losses, and packet disorders. Finally, a switched RLC circuit shows the feasibility of the proposed method.

Fully distributed dynamic event-triggered output regulation for heterogeneous linear multiagent systems under fixed and switching topologies

Fully distributed dynamic event-triggered output regulation for heterogeneous linear multiagent systems under fixed and switching topologies

Semiglobal Periodic Event-Triggered Output Regulation for Nonlinear Multiagent Systems

This study focuses on periodic event-triggered (PET) cooperative output regulation problem for a class of nonlinear multiagent systems. The key feature of PET mechanism is that event-triggered conditions are required to be monitored only periodically. This approach is beneficial for Zeno behavior exclusion and saving of battery energy of onboard sensors. At first, new PET distributed observers are proposed to estimate the leader information. We show that the estimation error converges to zero exponentially with a known convergence rate under asynchronous PET communication. Second, a novel PET output feedback controller is designed for the underlying strict feedback nonlinear multiagent systems. Based on a state transformation technique and a local PET state observer, the cooperative semiglobal output regulation problem can be solved by the proposed new control design technique. Simulation results of multiple Lorenz systems illustrate that the developed control scheme is effective.

Memory-Based Event-Triggered Output Regulation for Networked Switched Systems With Unstable Switching Dynamics.

This article studies an event-triggered asynchronous output regulation problem (EAORP) for networked switched systems (NSSs) with unstable switching dynamics (USDs) including all modes unstable and partial switching instants destabilization, which means that the Lyapunov function increases both on the activation intervals of all subsystems and at some switching instants. First, a memory-based mode-compared event-triggered mechanism for switched systems is proposed to effectively shorten asynchronous intervals, which employs historical sampled outputs and compares the mode of the current sampled instant and the adjacent sampled instant. Then, the maximum average dwell time for a novel switching signal is derived with a constraint on the ratio of total destabilizing switchings to total stabilizing switchings, which relaxes the requirement of the regular arrangement of destabilizing and stabilizing switchings. Moreover, with the help of different coordinate transformations in the EAORP, the discretized Lyapunov functions are no longer needed when synthesizing the NSSs with USDs, and the asynchronous switching situation is also discussed. Afterward, by designing a dynamic output feedback controller, sufficient conditions are given to solve the EAORP for NSSs with USDs subject to network-induced delays, packet disorders, and packet losses. Finally, the effectiveness of the proposed methods is verified via a switched RLC circuit.

Output regulation for networked switched systems with alternate event-triggered control under transmission delays and packet losses

This paper is concerned with the event-triggered output regulation problem for a class of linear networked switched systems (NSSs). A mode-dependent alternate event-triggered mechanism (AETM) is integrated into the NSSs with transmission delays and packet losses for the first time based on continuous detection and periodic sampling, and a joint-designed switching signal with the triggering information is presented. Under transmission delays and packet losses, a series of resultant error feedback controllers are synthesized in four cases based on the relationships between switching instants and event-triggered instants. Then, a criterion ensuring asynchronous output regulation performance is formed with transmission delays by the input delay method. With the presence of packet losses, a set of sufficient conditions is also dedicated to the proposed control issue by adding the restraint in the number of successive packet losses associated with a modified AETM. Eventually, a comparison and an F-18 aircraft model reveal the effectiveness of the obtained results in the simulation.

Output regulation for the parametric strict-feedback system via the event-triggered adaptive updating algorithm

In this paper, the adaptive event-triggered output regulation problem for the parametric strict feedback system is addressed. The adaptive control strategy over the plant-control communication network is developed and governed by the transmission sampled data of the plant, completely. By introducing an augment dynamic to compensate the event-triggered measurement errors, the event-triggered mechanism is developed independent on the stability of the adaptive algorithm. Therefore, a more flexible and robust event-triggered mechanism is proposed than the existing method where the threshold coefficients are constrained with the closed-loop system stable requirement. It is proved that, the asymptotical output regulation error upper bound is continuously dependent on the event-triggered threshold coefficient, but independent on the upper bound of unknown parameters. Therefore, the output regulation error upper bound can be modified by the feedback gains and threshold coefficients without considering the bounded unknown parameters. What’s more, the Zeno phenomenon is discussed carefully and excluded. Finally, the event-triggered adaptive control method is applied to control the double-rod electro-hydraulic servo system. It is shown that, the proposed scheme has smaller output regulation error than the existing methods with less communication times.

Periodic event-triggered output regulation for linear multi-agent systems

This study considers the problem of periodic event-triggered (PET) cooperative output regulation for a class of linear multi-agent systems. The advantage of the PET output regulation is that the data transmission and triggered condition are only needed to be monitored at discrete sampling instants. It is assumed that only a small number of agents can have access to the system matrix and states of the leader. Meanwhile, the PET mechanism is considered not only in the communication between various agents, but also in the sensor-to-controller and controller-to-actuator transmission channels for each agent. The above problem set-up will bring some challenges to the controller design and stability analysis. Based on a novel PET distributed observer, a PET dynamic output feedback control method is developed for each follower. Compared with the existing works, our method can naturally exclude the Zeno behavior, and the inter-event time becomes multiples of the sampling period. Furthermore, for every follower, the minimum inter-event time can be determined a prior, and computed directly without the knowledge of the leader information. An example is given to verify and illustrate the effectiveness of the new design scheme.

Event-Triggered Output Regulation for Networked Flight Control System Based on an Asynchronous Switched System Approach

In this article, the event-triggered output regulation problem is investigated for a networked flight control system with a switched system approach. By properly scheduling triggered times of periodic sampling associated with continuous event-triggering and switching instants of each subsystem, an alternate event-triggered mechanism based on the subsystem model is proposed to transmit the triggered information to the candidate controller. Since the subsystem may switch between two adjacent events while the corresponding controller does not switch, asynchronous switching may occur. Meanwhile, an event-triggered switching signal caused by asynchronous switching is designed with the mode-dependent average dwell time approach and event-triggered instants. By constructing multiple Lyapunov functions in the framework of the input delay approach and designing an error feedback controller, the sufficient condition for event-triggered asynchronous output regulation problem is solved. Finally, the proposed methods are proved to be effective by the F-18 aircraft model.

Event-Triggered Output Regulation of Heterogeneous Multiagent Networks

This technical note addresses the event-triggered output regulation problem of heterogenous multiagent systems. In contrast to similar problems solved by algorithms based on continuous communication between neighboring agents, a distinctive feature of the proposed algorithm is that communication from one agent to another is mediated by the corresponding triggering condition of the link. The output regulation problem is solved by a distributed design of predictors, observers, detectors, and controllers. In addition, positive lower bounds of interevent times for all links are provided. The effectiveness of the proposed algorithm is demonstrated by a numerical example.

Event-Triggered Output Regulation for A Class of Switched Linear Systems with Average Dwell Time Approach*

This paper studies the output regulation problem for a class of switched linear systems via designing an event-triggered state feedback controller. Compared with the time-triggered mechanism, event-triggered mechanism effectively reduces execution times of a control task. The designing of the controller for switched systems is difficult due to the mixture of event-triggered instants and switching instants. This paper gets sufficient conditions for the output regulation problem to be solvable by giving a co-design scheme of an event-triggered mechanism, state feedback controllers and switching rules satisfying the average dwell time (ADT) condition. The different coordinate transformations break the restrictions of a common solution for regulator equations of all subsystems. Moreover, the minimum inter-event interval is given to avoid Zeno behavior. Finally, a simulation example of the switched RLC circuit systems shows the validity of the results.

Distributed event-triggered output regulation of multi-agent systems

Motivated by the future use of embedded microprocessors with limited resources and limited computational resources, the distributed output regulation with event-driven strategies problem of linear multi-agent systems is considered in this paper. The main task is to design distributed feedback by employing event-triggered technique for multi-agent systems such that all agents can track an active leader, and/or distributed disturbance rejection. Both leader and disturbance are generated by some external system (exosystem). Both distributed static and dynamic feedback with event-triggered strategy are constructed here. Then, the input-to-state stability of the closed-loop multi-agent system is analysed. Finally, a numerical example is given to validate the proposed control.