Event-Triggered Static Output Feedback Simultaneous H∞ Control for a Collection of Networked Control Systems

This chapter considers the design of event-triggered static output feedback simultaneous H∞ controllers for a collection of networked control systems (NCSs). It is shown that conventional point-to-point wiring delayed static output feedback simultaneous H∞ controllers can be obtained by solving linear matrix inequalities (LMIs) with a linear matrix equality (LME) constraint. Based on an obtained simultaneous H∞ controller, an L2-gain event-triggered transmission policy is proposed for reducing the network usage. An illustrative example is presented to verify the obtained theoretical results

Observer-Based Disturbance Rejection Control for Switched Nonlinear Networked Systems under Event-Triggered Scheme

This paper employs the disturbance rejection technique for a class of switched nonlinear networked control systems (SNNCSs) with an observer-based event-triggered scheme. To estimate the influence of exogenous disturbances on the proposed system, the equivalent input disturbance (EID) technique is employed to construct an EID estimator. To provide adequate disturbance rejection performance, a new control law is built that includes the EID estimation. Furthermore, to preserve communication resources, an event-based mechanism for control signal transmission is devised and implemented. The primary goal of this work is to provide an observer-based event-triggered disturbance rejection controller that ensures the resulting closed-loop form of the examined systems is exponentially stable. Specifically, by employing a Lyapunov–Krasovskii approach, a new set of sufficient conditions in the form of linear matrix inequalities (LMIs) is derived, ensuring the exponential stabilization criteria are met. Eventually, a numerical example is used to demonstrate the efficacy and practicality of the proposed control mechanism

Simultaneous H ∞ Control for a Collection of Nonlinear Systems in Strict-Feedback Form

Based on the control storage function approach, a constructive method for designing simultaneous H∞ controllers for a collection of nonlinear control systems in strict-feedback form is developed. It is shown that under mild assumptions, common control storage functions (CSFs) for nonlinear systems in strict-feedback form can be constructed systematically. Based on the obtained common CSFs, an explicit formula for constructing simultaneous H∞ controllers is presented. Finally, an illustrative example is provided to verify the obtained theoretical results

Metabolic syndrome and abdominal fat are associated with inflammation, but not with clinical outcomes, in peritoneal dialysis patients

BACKGROUND: In the general population, metabolic syndrome (MetS) is correlated with visceral fat and a risk factor for cardiovascular disease (CVD); however, little is known about the significance of abdominal fat and its association with inflammation and medication use in peritoneal dialysis (PD) patients. We investigated the relationship of visceral fat area (VFA) with C-reactive protein (CRP) levels and medication use in PD patients and followed their clinical outcomes. METHODS: In a prospective study from February 2009 to February 2012, we assessed diabetes mellitus (DM) status, clinical and PD-associated characteristics, medication use, CRP levels, components of MetS, and VFA in 183 PD patients. These patients were categorized into 3 groups based on MetS and DM status: non-MetS (group 1, n = 73), MetS (group 2, n = 65), and DM (group 3, n = 45). VFA was evaluated by computed tomography (CT) and corrected for body mass index (BMI). RESULTS: Patients in group 1 had smaller VFAs than patients in groups 2 and 3 (3.2 ± 1.8, 4.6 ± 1.9, and 4.9 ± 2.0 cm(2)/[kg/m(2)], respectively, P < 0.05) and lower CRP levels (0.97 ± 2.31, 1.27 ± 2.57, and 1.11 ± 1.35 mg/dL, respectively, P < 0.05). VFA increased with the number of criteria met for MetS. After adjusting for age, body weight, and sex, CRP and albumin levels functioned as independent positive predictors of VFA; on other hand, the use of renin-angiotensin system blockers was inversely correlated with VFA in PD patients without DM. In the survival analysis, DM patients (group 3) had the poorest survival among the 3 groups, but no significant differences were found between groups 1 and 2. CONCLUSION: This study showed that VFA and MetS are associated with CRP levels but cannot predict survival in PD patients without DM. The complex relationship of nutritional parameters to VFA and MetS may explain these results. The type of antihypertensive medication used was also associated with the VFA. The mechanisms behind these findings warrant further investigation

State-Constrained Nonlinear L2–Gain Control

[[abstract]]In this note, a novel barrier storage function approach is developed to solve the L2–gain control problem for nonlinear control-affine systems under functional-inequality state constraints. The existence of barrier storage functions is shown to be sufficient for guaranteeing the existence of state-constrained L2–gain controllers. Sufficient conditions for the existence of barrier storage functions are derived. Finally, a numerical example is given for illustration.[[notice]]補正完

Finite-Time Asynchronous Event-Triggered Control for Switched Nonlinear Cyber-Physical Systems With Quantization

This study examines the finite-time event-triggered control (ETC) problem for nonlinear switched cyber-physical systems (NSCPSs) by using an asynchronous switching strategy. An ETC scheme, along with a measurement size reduction technique, has been implemented to decrease network communication burden and redeem network resources. Data quantization is also another efficient method for reducing the amount of transmitted data via networks. Meanwhile, asynchronous phenomena among ETC instants are studied, which is much more realistic and difficult in the system under consideration. The prime intent of this research is to enhance the asynchronous event-triggered control (AETC) technique to guarantee the resulting closed-loop NSCPS is finite-time bounded (FTB) and prespecified mixed $H_{\infty}$ and passive performance index $\gamma$ in the finite-time horizon. A novel set of required conditions in the form of linear matrix inequalities (LMIs) is enhanced using the Lyapunov-Krasovskii functional (LKF) theory, ensuring that the FTB criterion is met. Furthermore, the gains are acquired by solving a group of LMIs. Ultimately, a numerical illustration is provided, showcasing the efficaciousness and practicality of the developed control strategy through a real-world application known as the vertical take-off and landing helicopter model (VTOLHM)

The method of measuring peritoneal calcification (PC).

<p>PC located in the abdominal wall and bowel wall was circled as the region of interest. The software ImageJ quantified the calcification areas of more than 150 Hounsfield units (table in the figure). The Tenckhoff catheter and vascular calcification were excluded from measurement.</p