skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Observer-based event-triggered boundary control of the one-phase Stefan problem
This paper presents an observer-based event-triggered boundary control strategy for the one-phase Stefan problem, utilising the position and velocity measurements of the moving interface. The design of the observer and controller is founded on the infinite-dimensional backstepping approach. To implement the continuous-time observer-based controller in an event-triggered framework, we propose a dynamic event triggering condition. This condition specifies the instances when the control input must be updated. Between events, the control input is maintained constant in a Zero-Order-Hold manner. We demonstrate that the dwell-time between successive triggering moments is uniformly bounded from below, thereby precluding Zeno behaviour. The proposed event-triggered boundary control strategy ensures the wellposedness of the closed-loop system and the satisfaction of certain model validity conditions. Additionally, the global exponential convergence of the closed-loop system to the setpoint is established using Lyapunov approach. A simulation example is provided to validate the theoretical findings.  more » « less
Award ID(s):
2222250
PAR ID:
10565910
Author(s) / Creator(s):
;
Publisher / Repository:
Taylor & Francis
Date Published:
Journal Name:
International Journal of Control
Volume:
97
Issue:
12
ISSN:
0020-7179
Page Range / eLocation ID:
2975 to 2986
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; (, 2018 IEEE Conference on Decision and Control (CDC))
    This paper presents a Q-Iearning based dynamic intermittent mechanism to control linear systems evolving in continuous time. In contrast to existing event-triggered mechanisms, where complete knowledge of the system dynamics is required, the proposed dynamic intermittent control obviates this requirement while providing a quantified level of performance. An internal dynamical system will be introduced to generate the triggering condition. Then, a dynamic intermittent Q-Iearning is developed to learn the optimal value function and the hybrid controller. A qualitative performance analysis of the dynamic event-triggered control is given in comparison to the continuous-triggered control law to show the degree of suboptimality. The combined closed-loop system is written as an impulsive system, and it is proved to have an asymptotically stable equilibrium point without any Zeno behavior. A numerical simulation of an unknown unstable system is presented to show the efficacy of the proposed approach. 
    more » « less
  2. ; ; (, International Journal of Robust and Nonlinear Control)
    Abstract Periodic event‐triggered control (PETC) evaluates triggering conditions only at periodic sampling times, based on which it is decided whether the controller needs to be updated. This article investigates the global stabilization of nonlinear systems that are affected by external disturbances under PETC mechanisms. Sufficient conditions are provided to ensure the resulting closed‐loop system is input‐to‐state stable (ISS) for the state feedback and the observer‐based output feedback configurations separately. The sampling period and the triggering functions are chosen such that the ISS‐Lyapunov function of continuous dynamics is also the ISS‐Lyapunov function of the overall system. Based on that, sufficient conditions in the form of linear matrix inequalities are provided for the PETC design of incrementally quadratic nonlinear systems. Two simulation examples are provided to illustrate the effectiveness of the proposed method. 
    more » « less
  3. ; (, IMA Journal of Mathematical Control and Information)
    Abstract This paper presents dynamic design techniques—namely, continuous-time event-triggered control (CETC), periodic event-triggered control (PETC) and self-triggered control (STC)—for a class of unstable one-dimensional reaction-diffusion partial differential equations (PDEs) with boundary control and an anti-collocated sensing mechanism. For the first time, global exponential stability (GES) of the closed-loop system is established using a PDE backstepping control design combined with dynamic event-triggered mechanisms for parabolic PDEs—a result not previously achieved even under full-state measurement. When the emulated continuous-time backstepping controller is implemented on the plant using a zero-order hold, our design guarantees $$ L^{2} $$-GES through the integration of novel switching dynamic event triggers and a newly developed Lyapunov functional. While CETC requires the continuous monitoring of the triggering function to detect events, PETC only requires the periodic evaluation of this function. The STC design assumes full-state measurements and, unlike CETC, does not require continuous monitoring of any triggering function. Instead, it computes the next event time at the current event time using only full-state measurements available at the current event time and the immediate previous event time. Thus, STC operates entirely with event-triggered measurements, in contrast to CETC and PETC, which rely on continuous measurements. The well-posedness of the closed-loop systems under all three strategies is established, and simulation results are provided to illustrate the theoretical results. 
    more » « less
  4. ; ; ; ; ; (, 2018 37th Chinese Control Conference (CCC))
    This paper presents a novel intermittent suboptimal event-triggered controller design for continuous-time nonlinear systems. The stability of the equilibrium point of the closed-loop system, and the performances are analyzed and quantified theoretically. It is proven that the static and the dynamic event-triggered suboptimal controllers have a known degree of suboptimality compared to the conventional optimal control policy. In order to generate dynamic event-triggering framework, we introduce an internal dynamical system. Moreover, the Zeno behavior is excluded. Finally, a simulation example is conducted to show the effectiveness of the proposed intermittent mechanisms. 
    more » « less
  5. ; ; (, IEEE Transactions on Power Systems)
    null (Ed.)
    This paper proposes a finite-time event-triggered secondary frequency and voltage control for islanded AC microgrids (MGs) in a distributed fashion. The proposed control strategy can effectively perform frequency restoration and voltage regulations, while sharing the active and reactive power among the distributed generators (DGs) based on their power ratings. The finite-time control enables a system to reach consensus in a finite period of time enhanced from the asymptotic convergence. The event-triggered communication is utilized to reduce the communication burden among the DG controllers by transmitting data among DGs if an event-triggering condition is satisfied. The performance of the proposed finite-time event-triggered frequency control is verified utilizing a hardware-in-the-loop experimental testbed which simulates an AC MG in Opal-RT. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email