ABSTRACT
This article investigates the optimal consensus problem for general linear multiagent systems (MASs) via a dynamic event-triggered approach. First, a modified interaction-related cost function is proposed. Second, a dynamic event-triggered approach is developed by constructing a new distributed dynamic triggering function and a new distributed event-triggered consensus protocol. Consequently, the modified interaction-related cost function can be minimized by applying the distributed control laws, which overcomes the difficulty in the optimal consensus problem that seeking the interaction-related cost function needs all agents' information. Then, some sufficient conditions are obtained to guarantee optimality. It is shown that the developed optimal consensus gain matrices are only related to the designed triggering parameters and the desirable modified interaction-related cost function, relaxing the constraint that the controller design requires the knowledge of system dynamics, initial states, and network scale. Meanwhile, the tradeoff between optimal consensus performance and event-triggered behavior is also considered. Finally, a simulation example is provided to verify the validity of the designed distributed event-triggered optimal controller.
ABSTRACT
This work investigates the issue of output-feedback sliding-mode control (SMC) for nonlinear 2-D systems by Takagi-Sugeno fuzzy-affine models. Via combining with the sliding surface, the sliding-mode dynamical properties are depicted by a singular piecewise-affine system. Through piecewise quadratic Lyapunov functions, new stability and robust performance analysis of the sliding motion are carried out. An output-feedback dynamic SMC design approach is developed to guarantee that the system states can converge to a neighborhood of the sliding surface. Simulation studies are given to verify the validity of the proposed scheme.
ABSTRACT
This article focuses on the sampled-data output-feedback control problem for nonlinear systems represented by Takagi-Sugeno fuzzy affine models. An input delay approach is adopted to describe the sample-and-hold behavior of the measurement output. Via augmenting the system states with the control input, the resulting closed-loop system is converted into a singular system first. Based on the piecewise quadratic Lyapunov-Krasovskii functionals, some novel results on the sampled-data piecewise affine output-feedback controller design are attained by employing some convexification techniques. The simulation studies are presented to illustrate the effectiveness of the proposed scheme.
ABSTRACT
This article studies the asynchronous sampled-data filtering design problem for Itô stochastic nonlinear systems via Takagi-Sugeno fuzzy-affine models. The sample-and-hold behavior of the measurement output is described by an input delay method. Based on a novel piecewise quadratic Lyapunov-Krasovskii functional, some new results on the asynchronous sampled-data filtering design are proposed through a linearization procedure by using some convexification techniques. Simulation studies are given to illustrate the effectiveness of the proposed method.
ABSTRACT
BACKGROUND: Dyslipidemia caused by liver injury is a significant risk factor for cardiovascular complications. Previous studies have shown that hydrogen sulfide (H2S) protects against multiple cardiovascular disease states in a similar manner as nitric oxide (NO), and NO/endothelial nitric oxide synthase (eNOS) pathway is the key route of NO production. The purpose of this study was to investigate whether H2S can ameliorate the high blood pressure and plasma lipid profile in Nw-nitro-L-argininemethyl ester (L-NAME)-induced hypertensive rats by NO/eNOS pathway. METHODS: Thirty-six 4-week old Sprague-Dawley (SD) male rats were randomly assigned to 6 groups (n = 6): control group, L-NAME group, control + glibenclamide group, control + NaHS group, L-NAME + NaHS group, and L-NAME + NaHS + glibenclamide group. Measurements were made of plasma triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (CHO), glutamic-pyruvic transaminase (ALT) levels after 5 weeks. Then measurements of NO level and proteins expression of eNOS, P-eNOS, AKT, P-AKT were made in liver tissue. RESULTS: After 5 weeks of L-NAME treatment, the blood pressure, plasma TG ((1.22±0.12) mmol/L in L-NAME group vs. (0.68±0.09) mmol/L in control group; P < 0.05) and LDL ((0.54±0.04) mmol/L in L-NAME group vs. (0.28±0.02) mmol/L in control group; P < 0.05) concentration were significantly increased, and the plasma HDL ((0.26±0.02) mmol/L in L-NAME group vs. (0.69±0.07) mmol/L in control group; P < 0.05) concentration significantly decreased. Meanwhile the rats treated with L-NAME exhibit dysfunctional eNOS, diminished NO levels ((1.36±0.09) mmol/g protein in L-NAME group vs. (2.34±0.06) mmol/g protein in control group; P < 0.05) and pathological changes of the liver. H2S therapy can markedly decrease the blood pressure ((37.25±4.46) mmHg at the fifth week; P < 0.05), and ameliorate the plasma TG ((0.59±0.06) mmHg), LDL ((0.32±0.04) mmHg), and HDL ((0.46±0.03) mmHg) concentration in L-NAME + NaHS group (all P < 0.05). H2S therapy can also restore eNOS function and NO bioavailability and attenuate the pathological changes in the liver in L-NAME-induced hypertensive rats. CONCLUSION: H2S protects the L-NAME-induced hypertensive rats against liver injury via NO/ eNOS pathway, therefore decreases the cardiovascular risk.
