Event-triggered optimal tracking control of nonlinear systems

Wei

2018

Summary This paper studies the robust stabilization problem of constrained‐input nonlinear systems with mismatched uncertainties. Initially, the robust stabilization problem is converted into a constrained H2 optimal control problem by providing a proper infinite‐horizon cost function for the auxiliary system. It is demonstrated that the solution of the constrained H2 optimal control problem can force the original system to be stable in the sense of uniform ultimate boundedness. Then, under the framework of reinforcement learning, an off‐policy iteration algorithm is proposed to solve the constrained H2 optimal control problem. The off‐policy iteration algorithm is implemented by using two kinds of approximators. That is, the critic approximator is applied to approximate the optimal cost function and the actor approximator is used to approximate the augmented optimal control. The method of weighted residuals together with the Monte‐Carlo integration technique is employed to determine the weight parameters of critic and actor approximators. Finally, two examples, including a pendulum system, are presented to validate the proposed control algorithm.

Section: Resultsmentioning

confidence: 99%

An off‐policy iteration algorithm for robust stabilization of constrained‐input uncertain nonlinear systems

Wei

2018

“…However, it is sometimes less preferable, especially during the peak of communications, because the sampling takes place periodically regardless of whether the current behaviors of the system states needs or not. In order to make up for the shortcomings of periodic data sampling, another control method, namely, event‐based control strategy, emerges as the times require . More specifically, an introduction of event‐triggered control and self‐triggered control for linear systems was provided in the work of Heemels et al Subsequently, Wu et al investigated the problem of event‐triggered control for directly observable discrete‐time linear systems subject to exogenous disturbances.…”

Section: Introductionmentioning

confidence: 99%

Event‐triggered control for a class of strict‐feedback nonlinear systems

Zhang

2019

Summary This paper is concerned with the event‐triggered control problem for a class of strict feedback nonlinear networked systems. Different from the existing design methods, a novel user‐adjustable event‐triggered mechanism is first developed to determine the sampling state instants using the negative definite property of the derivatives of Lyapunov functions. Then, an event‐triggered control strategy is devised based on the sampled state vectors and backstepping techniques. It is proved that the proposed control scheme ensures the global convergence of the closed‐loop systems via Lyapunov analyses and the correlation criteria of real variable functions. Finally, two examples are performed to illustrate the effectiveness of the provided control approaches.

“…This implies that the control tasks being executed at an arbitrarily large frequency is impossible, that is, the Zeno behavior must be taken into consideration . Accordingly, the analysis of the Zeno behavior is significant for event‐triggered issue of the continuous‐time systems . In the works of Abdelrahim et al and Selivanov and Fridman, the signal transmission needs to wait for a fixed amount of time after each sampling instant to overcome the Zeno behavior.…”

Section: Introductionmentioning

confidence: 99%

“…15 Accordingly, the analysis of the Zeno behavior is significant for event-triggered issue of the continuous-time systems. 16 In the works of Abdelrahim et al 17 and Selivanov and Fridman, 18 the signal transmission needs to wait for a fixed amount of time after each sampling instant to overcome the Zeno behavior. Some analyses have been provided to show that the Zeno behavior has been avoided by establishing a positive constant lower bound on the minimum interevent interval.…”

Section: Introductionmentioning

confidence: 99%

A novel event‐triggered extended state observer for networked control systems subjected to external disturbances

Yuan

et al. 2019

Summary In this paper, the event‐triggered‐based state estimation problem is investigated for a class of nonlinear networked control systems subjected to external disturbances. A novel event‐triggered extended state observer (ESO) is utilized to estimate the so‐called total disturbance, and an output predictor is adopted for the proposed ESO between two consecutive transmission instants. It is also worth pointing out that, in the newly proposed ESO, an event‐triggered mechanism is adopted to update the measurement signal so as to save the communication resource. The sufficient conditions are provided such that the estimation error dynamics is exponentially ultimately bounded. Furthermore, it is proven that the Zeno behavior does not exist for the event‐triggering rules. A number of numerical simulations are conducted to verify the validity of the theoretical results.