International Journal of Robust and Nonlinear Control最新文献

This article investigates the controller design for a game-based distributed control problem for multiple Euler–Lagrange systems over switching topologies, in which the objective is to stabilize each Euler–Lagrange system and minimize the local cost function of an agent simultaneously. The communication topologies are switching among a set of weight-balanced digraphs, and the dynamic of an Euler–Lagrange agent includes unknown parts. In this problem, agents have limited observation of others' states, but agents can estimate other states by exchanging information with their neighbors over switching topologies. The coupling states of agents, uncomplete states, and switching topologies are such that existing distributed control strategies cannot address this problem. In this regard, two distributed controllers are respectively proposed for this game-based distributed control problem with known and unknown dynamics based on the feedback linearization, consensus-based estimation, gradient play, and integral compensation. Based on the time-scale decomposition technique and orthogonal decomposition method, it proves that the proposed controllers can stabilize the Euler–Lagrange agent and are such that the local state is pushed to the Nash equilibrium, and the communication topology is allowed to be arbitrarily switched among different digraphs. Lastly, the simulation demonstrates the effectiveness of proposed controllers.

A fixed-time consensus control protocol is proposed for uncertain nonlinear multi-agent systems (MASs) with time-varying state constraints. By applying the time-varying barrier Lyapunov functions (BLFs), an adaptive consensus control protocol is constructed to make certain that all system states maintain within the predetermined time-varying ranges. Meanwhile, an event-triggered mechanism (ETM) is established to alleviate the burden of MASs communication. Besides, to guarantee the control performance, a fixed-time control method based on neural networks (NNs) is developed. It is demonstrated that the MASs can synchronize in a fixed time, and the state constraints are satisfied. Finally, two simulation examples demonstrate the effectiveness of the presented protocol.

This article is committed to the matter of asynchronous dynamic output feedback control for a class of Takagi–Sugeno fuzzy Markov jump systems. The principal concept is to construct a high-level Markovian process governed controller under an asynchronous event-triggered scheme and to develop a time-varying dissipative index. As a salient feature that distinguishes it from the reported works with the common index, this paper firstly proposes a dissipative index with mode and membership functions-dependence. Secondly, governed by the high-level Markovian process, the asynchronous dynamic output feedback controller is constructed under the mode-dependent partitioned regions. Meanwhile, to mitigate the communication pressure, an asynchronous dynamic event-triggered mechanism is investigated with making allowances for the inaccessible system mode. What's more, as a first effort, this article presents a unified framework for co-designing the strategy of asynchronous event generators and controllers. This is done under the proposed performance index and the mode-dependent fuzzy state-space partitions, resulting in more design flexibility. Based on the mode and region-dependent Lyapunov functional, sufficient criteria are obtained to ensure the proposed dissipative performance and stochastic stability. Eventually, the practicabilities and advantages of the theoretic results are illustrated by a modified tunnel diode circuit model.

This paper addresses a switched sampled-data control design for stabilization of the N-dimensional (N-D) semilinear heat equation with a mobile actuator. It is supposed that discrete-time averaged measurements are available. The system is known to be stabilizable by the static output-feedback employing several distributed in space actuators and sensors, but is not stabilizable by only one of the actuator-sensor pairs. Does there exist a switching stabilizing static output-feedback such that at all times, only one actuator-sensor pair is active? In our recent paper we gave a positive answer and found the appropriate switching sampled-data time-triggered control law for the one-dimensional (1-D) case. In this paper, to enlarge the time between switching (which means to reduce the frequency of actuator moving to the active domain), we present an event-triggered control for stabilization by switching. Moreover, we extend the results for stabilization by switching to the N-D case. Numerical examples show that the switching-based event-triggered controller essentially decreases the frequency of the actuator moving compared to the time-triggered controller, reducing operating costs.

In this article, we investigate globally exponential synchronization problems in delayed complex dynamic networks (DCDNs) characterized by both time-varying impulsive delay and gain (TIDG). Our research is grounded on the Halanay inequality, which serves as the keystone of our analysis. Adopting the method of average impulsive delay-gain (AIDG), we formulate criteria for globally exponential synchronization dependent on the overall impulsive disturbances. Our criteria reveal the negative effect of AIDG on synchronization, which hinders the synchronization process. Additionally, we refine the concept of average impulsive gain to enhance its applicability. Furthermore, our results demonstrate that even in the simultaneous presence of desynchronizing and synchronizing impulses, along with time-varying impulsive delays, DCDNs are able to maintain the original synchronization under appropriate conditions, irrespective of whether the average impulsive interval is finite or not. Finally, we validate our theoretical findings by applying them to network examples.

In this work, the stability problem of nonlinear stochastic systems is investigated under exogenous disturbances through event-triggered impulsive control (ETIC). The ETIC strategy proposed in this paper incorporates three levels of events, taking into account four indicators: threshold, control-free index, inspection interval, and waiting time for stochastic systems, which is more practically significant and can effectively eliminate the Zeno behavior. By utilizing Lyapunov stability theory, stochastic analysis techniques, and some fundamental inequalities, sufficient conditions for the $��r�\text{th}�$ moment input-to-state stability ($��r�$-ISS) and exponentially $��r�$-ISS of the considered system can be achieved through the implementation of the designed ETIC. Then, the theoretical results are employed in actual nonlinear stochastic systems, leading to the establishment of LMI-based criteria for exponential $��r�$-ISS. Ultimately, the feasibility of ETIC strategy is confirmed through two instances.

In this article, the finite-time functional interval estimation method for nonlinear discrete-time switched descriptor systems with perturbations is investigated. To deal with the nonlinear terms in the switched system, the nonlinear error system is converted into a linear parameter varying form using the reformulated Lipschitz property. Firstly, a functional observer with finite-time $��{�ℒ�}_{�2�}�$ gain is constructed for the nonlinear switched descriptor system. Then, based on the proposed finite-time functional observer, the reachability analysis is applied to design a finite-time functional interval observer. Finally, the superiority and effectiveness of the interval estimation method presented in this paper are verified through a simulation of the circuit system.

Real-world dynamical controlled systems are often subject to input saturation due to the physical constraints of actuators. This causes the response performance of the system to be degraded. To this end, we propose a high-performance bounded finite time control (HP-BFTC) method based on sliding mode control for finite time tracking of linear systems with input saturation. In this method, a novel concept of rate regulation finite-time stability is proposed to achieve better steady-state performance. A bounded controller based on sliding mode control is proposed to achieve finite-time stability in rate regulation, wherein a finite time approach rate based on an inverse tangent function is presented to alleviate chattering caused by sign function, and two control parameters are introduced to improve response performance. The rate regulation finite-time stability of the system is proved in the estimated domain of attraction. In addition, a parameter tuning principle is given to enhance the response performance of the closed-loop system in transient and steady state. The superiority of the proposed method in performance is verified by a case study.

This paper investigates the stability and stabilization problems of fractional-order systems with distributed delays (FOSDDs). Firstly, with the frequency sweeping technique and generalized Kalman-Yakubovi$��\check{�c�}�$-Popov (KYP) lemma, a novel stability condition for FOSDDs is proposed. Secondly, based on the proposed stability condition, a robust stability condition for the uncertain FOSDDs with norm-bounded uncertainties is derived. Thirdly, based on the proposed robust stability condition, a novel stabilization condition for the uncertain FOSDDs with norm-bounded uncertainties is obtained. Finally, several numerical examples are provided to show the effectiveness of the proposed results. Moreover, in the numerical examples, the comparison of the proposed results with the existing results for FOSDDs is shown to demonstrate that the obtained results are less conservative.

Via event-triggered strategy, full-order and reduced-order $��H_{\infty }�$ filtering syntheses are addressed for uncertain switched systems in the paper. Norm-bounded uncertainty is considered in each switched subsystem. An event-triggered strategy is primarily specified to determine whether the information of an uncertain switched system is transmitted or not. Full-order and reduced-order $��H_{\infty }�$ filters are considered on account of the outputs of the proposed event-triggered strategy. By the merging switching signal technique, it can be established as a switched filtering error system with uncertain switched systems. Some sufficient conditions are subsequently presented to ensure exponential stability (ES) with weighted $��H_{\infty }�$ performance for the filtering error system. Moreover, some devised methods of full-order and reduced-order $��H_{\infty }�$ filters are also given, and therefore $��H_{\infty }�$ filters with different orders can be selected according to different needs in practical applications. A lower bound more than zero is found to exclude Zeno behavior on the event-triggered intervals. Finally, the validity and feasibility of this study are illustrated by a practical example.