Adaptive Time-Varying Formation Tracking Control for Multiagent Systems With Nonzero Leader Input by Intermittent Communications.

The time-varying formation (TVF) tracking problem is studied for linear multiagent systems (MASs), where followers reach a preset TVF when tracking the leader's state. Followers are divided into the informed ones, which directly receive the leader's information, and uninformed ones. To alleviate communication requirements, trigger mechanisms are designed for the leader and all edges. Note that the designed trigger mechanisms enable the leader to send information intermittently and each follower to transmit information asynchronously when the corresponding trigger mechanism is satisfied. To address the TVF tracking problem, the node-event (for the leader) and (dynamic) edge-event triggered adaptive control strategy is proposed, which is fully distributed and has no relation to the system network's scale. Moreover, the MASs do not exhibit the Zeno behavior. Finally, a practice example is introduced to effectively illustrate the theoretical results.

Fault-Tolerant Control for Stochastic Switched IT2 Fuzzy Uncertain Time-Delayed Nonlinear Systems.

This article devotes to solve the fault-tolerant control problem based on interval type-2 (IT2) Takagi-Sugeno (T-S) fuzzy stochastic switched uncertain time-delayed systems with signal quantization. Stochastic switched systems can model a dynamic structure susceptible to abrupt faults, making it more practically significant in power systems or economic systems. The core design is an observer-based fault-tolerant control scheme that can estimate incomplete measurable variables and eliminate the influence of fault dynamically well and enhancing the robust stability of the systems subject to quantization effects. A novel method in seeking the upper bound solution of time-varying delay efficiently decreases conservativeness, especially for the proposed time-delayed system. The simulated analysis is specified to verify the availability and validity of the obtained design method.

Dissipativity-Based Intermittent Fault Detection and Tolerant Control for Multiple Delayed Uncertain Switched Fuzzy Stochastic Systems With Unmeasurable Premise Variables.

This study focuses on dissipativity-based fault detection for multiple delayed uncertain switched Takagi-Sugeno fuzzy stochastic systems with intermittent faults and unmeasurable premise variables. Nonlinear dynamics, exogenous disturbances, and measurement noise are also considered. In contrast to the existing study works, there is a wider range of applications. An observer is explored to detect faults. A controller is studied to stabilize the considered system. A piecewise fuzzy Lyapunov function is collected to obtain delay-dependent sufficient conditions by means of linear matrix inequalities. The designed observer has less conservatism. In addition, the strict [Formula: see text]dissipativity performance is achieved in the residual dynamic. Besides, the elaborate H∞ performance and the elaborate H_ performance are also acquired. Finally, the availability of the method in this study is verified through two simulation examples.

Leader-Following Consensus for a Class of Nonlinear Multiagent Systems Under Event-Triggered and Edge-Event Triggered Mechanisms.

Considering that there are many systems with limited network bandwidth in practice, this article studies the leader-following consensus problem for a class of nonlinear multiagent systems (MASs). The purpose of this article is to reduce unnecessary information transmission between any pair of adjacent agents including the leader in the MASs through intermittent communication. The novel event-triggered and asynchronous edge-event triggered mechanisms are designed for the leader and all edges, respectively. The static and dynamic consensus protocols under these mechanisms are proposed to address the leader-following consensus problem for MASs with Lipschitz dynamics, and the systems will not exhibit Zeno behavior under these two control schemes. Note that the dynamic consensus protocol does not rely on any global values of MASs, it is a fully distributed way. Finally, a practice simulation example is introduced to illustrate the theoretical results obtained.

Dissipativity-Based Finite-Time Filtering for Uncertain Semi-Markovian Jump Random Systems With Multiple Time Delays and State Constraints.

This article is concerned with the issue of dissipativity-based finite-time multiple delay-dependent filtering for uncertain semi-Markovian jump random nonlinear systems with state constraints. There are multiple time-varying delays, nonlinear functions, and intermittent faults (IFs) in the systems. This is one of the few attempts for the issue studied in this article. First, a filter is designed for the uncertain semi-Markovian jump random nonlinear systems. An augmented system with regard to the resulting filtering error is acquired. Then, sufficient conditions of the augmented system are generated by the stochastic Lyapunov function. Finite-time boundedness (FTB) and input-output finite-time mean square stabilization (IO-FTMSS) are both realized. The effectiveness and feasibility of the method are rendered via three examples.

Fault Estimation and Tolerant Control for Discrete-Time Multiple Delayed Fuzzy Stochastic Systems With Intermittent Sensor and Actuator Faults.

This article is concerned with observer-based fault estimation (FE) and tolerant controller design for a series of discrete-time Takagi-Sugeno (T-S) fuzzy stochastic systems. There exist multiple time-varying state delays, intermittent sensor and actuator faults, nonlinear dynamics, and exogenous disturbances in the systems. Compared with the results of the existence, this approach suggested in this article is more flexible and feasible. By means of the FE information, a novel fuzzy adaptive descriptor observer is developed to obtain the error dynamics. Then, an active observer-based fault-tolerant controller is designed to stabilize the closed-loop fuzzy system. Furthermore, a set of delay-dependent sufficient conditions are provided by the fuzzy Lyapunov function with the way of linear matrix inequalities (LMIs), which has less conservatism compared with the ones of the existing observers and fault-tolerant controllers. Finally, a simulation example is shown to illustrate the advantages and effectiveness of this approach depicted in this article.

Electroacupuncture for postmenopausal women with stress urinary incontinence: secondary analysis of a randomized controlled trial.

PURPOSE: The efficacy and safety of electroacupuncture was compared to those of sham electroacupuncture for the treatment of postmenopausal women with stress urinary incontinence (SUI). METHODS: This study was a secondary analysis of a multicenter, randomized controlled trial that recruited 504 women with SUI and randomized 349 postmenopausal women to receive 18 treatment sessions of electroacupuncture or sham electroacupuncture over 6 weeks, with a 24-week follow-up assessment. Treatment response was defined as a 50% or greater reduction in urine leakage, as measured by a 1-h pad test at week 6. RESULTS: Of the 349 randomized women, 332 completed the study. The response rate was 61.0% in the electroacupuncture group compared to 18.9% in the sham electroacupuncture group (difference 42.5%; 95% confidence interval, 33.3-51.7; p < 0.001). After 6 weeks of treatment, the mean 72-h urinary incontinence episode frequency, proportion of participants with at least a 50% decrease in mean 72-h incontinence episode frequency, participant-reported SUI severity, International Consultation on Incontinence Questionnaire-Short Form scores, and participants' self-evaluation of therapeutic effects improved in both groups, with significant between-group differences. Treatment-related adverse events occurred in 2.1% of women during the 6-week treatment. CONCLUSION: Electroacupuncture may effectively and safely relieve urinary incontinence symptoms and improve quality of life in postmenopausal women with SUI.

Dynamic output feedback-based fault-tolerant control design for T-S fuzzy systems with model uncertainties.

This paper is concerned with fault-tolerant control (FTC) for a class of nonlinear discrete-time systems. A dynamic output feedback controller is designed for Takagi-Sugeno (T-S) fuzzy systems with state and input parameter uncertainties, exogenous disturbances, measurement noise and multiple intermittent faults. Compared with the existing research results, the proposed controller has a wider application range. The stability of the closed-loop systems is guaranteed by H∞ performance and sufficient conditions are proposed for the considered system with multiple sensor faults, multiple actuator faults, multiple sensor and actuator faults, respectively, by solving linear matrix inequalities (LMIs). Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed FTC method in the paper.