This article studies the problem of dissipative control for singular Takagi–Sugeno fuzzy systems with time delay. In order to reduce the conservatism brought by the time delay, we choose a proper augmented Lyapunov–Krasovskii functional and the auxiliary-function-based integral inequality to analyze the admissibility and dissipativity of the system. The singularity of the derivative matrix of the system leads to the matrix coupling terms, which are difficult to handle in the controller design by using the common controller design methods, so we propose an iterative algorithm to solve the controller parameters. The sufficient conditions of ensuring that the closed-loop system is admissible and dissipative are presented. Finally, three persuasive examples are given to demonstrate the effectiveness of the proposed method.

This paper is concerned with the stability analysis for continuous-time positive singular systems with time-varying delays. First, an auxiliary system is introduced to establish the positivity condition for singular time-delay systems. Based on the positivity condition, the stability criterion is obtained for the positive singular systems with constant delays. By analyzing the monotonic property of the system trajectory, we extend the stability condition to the cases with time-varying delays. A numerical simulation is employed to illustrate the effectiveness of our results.

This paper investigates the tracking consistency regulation of high-order multi-agent systems (MASs) subject to Lipschitz nonlinear perturbations. Rooting at the leader node, the interagent interaction is described by a directed graph that contains a directed spanning tree. On designing the tracking protocol, an aperiodic data sampling scheme is introduced such that in-neighbors' information can be aperiodically sampled and transmitted via broadcast channels, where packet loss and communication delay are unavoidably existent. Thanks to algebraic graph theory and Lyapunov-Krasovskii functional technique, the concerned consensus tracking issue is cast into asymptotically stabilizing a class of switched nonlinear systems which consist of delayed and non-delayed components. It is proved that, moreover, the asymptotic stabilization of such systems essentially depends on packet loss characteristics. By explicitly characterizing the interplay among sampling interval, communication delay and network structure, consensualization criteria are formulated within the linear matrix inequality (LMI) framework. The design method is validated by numerical simulations.

This work solves the countermeasure design problems of distributed resilient output time-varying formation-tracking (TVFT) of heterogeneous multiagent systems (MASs) against general Byzantine attacks (GBAs). Inspired by the concept of Digital Twin, a hierarchical protocol equipped with a twin layer (TL) is proposed, which decouples the above problem into the defense against Byzantine edge attacks (BEAs) on the TL and the defense against Byzantine node attacks (BNAs) on the cyber–physical layer (CPL). First, a secure TL with respect to (w.r.t.) the high-order leader dynamics is designed, which achieves resilient estimation against BEAs. A trusted-node strategy against BEAs is proposed, which promotes network resilience by protecting almost the smallest fraction of crucial nodes on the TL. It is proven that strongly $(2f+1)$ -robustness w.r.t. the above trusted nodes is sufficient for the resilient estimation performance of the TL. Second, a decentralized adaptive and chattering-free controller against potentially unbounded BNAs is designed on the CPL. This controller has the merit of uniformly ultimately bounded (UUB) convergence and an assignable exponential decay rate when converging into the above UUB bound. To the best of our knowledge, this article is the first to achieve resilient output TVFT against GBAs, rather than under GBAs. Finally, the practicability and validity of this new hierarchical protocol are illustrated via a simulation example.

The analysis and design problems of formation-containment control for high-order linear time-invariant (LTI) multiagent systems (MASs) on directed graphs with observer-based output-feedback protocols are given in this work. To expand the feasibility of state formation configuration, two well-structured compensation signals are introduced for the leaders and followers in the protocols, respectively. Benefitting from the compensation signal of followers, the decoupling between formation control of leaders and containment control of followers is achieved. Thus, a necessary and sufficient condition is first established such that the formation-containment control for high-order LTI MASs can be achieved. Moreover, a heuristic iterative algorithm is developed to compute the controller gains, observer gains, as well as the compensation signals. Finally, two numerical examples are implemented to illustrate the time-varying formation-containment control of high-order MASs, which shows the validity and practicability of the theoretical results and algorithm.