Stochastic bounded consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with general sampling delay

In this paper we provide a unified framework for consensus tracking of leader-follower multi-agent systems with measurement noises based on sampled data with a general sampling delay. First, a stochastic bounded consensus tracking protocol based on sampled data with a general sampling delay is presented by employing the delay decomposition technique. Then, necessary and sufficient conditions are derived for guaranteeing leader-follower multi-agent systems with measurement noises and a time-varying reference state to achieve mean square bounded consensus tracking. The obtained results cover no sampling delay, a small sampling delay and a large sampling delay as three special cases. Last, simulations are provided to demonstrate the effectiveness of the theoretical results.

INITIAL-OBLIQUE DERIVATIVE PROBLEMS FOR NONLINEAR PARABOLIC SYSTEMS WITH MEASURABLE COEFFICIENTS

This paper deals with some initial-oblique derivative boundary value problems for nonlinear nondivergent parabolic systems of several second order equations with measurable coefficients in multiply connected domains. Firstly, a priori estimates of solutions for the initial-boundary value problems are given, and then by using the above estimates of solutions and the Leray-Schauder theorem, the existence and uniqueness of solutions for the problems are proved.

Active Disturbance Rejection Control for Uncertain Nonlinear Systems With Sporadic Measurements

This paper deals with the problem of active disturbance rejection control(ADRC)design for a class of uncertain nonlinear systems with sporadic measurements.A novel extended state observer(ESO)is designed in a cascade form consisting of a continuous time estimator,a continuous observation error predictor,and a reset compensator.The proposed ESO estimates not only the system state but also the total uncertainty,which may include the effects of the external perturbation,the parametric uncertainty,and the unknown nonlinear dynamics.Such a reset compensator,whose state is reset to zero whenever a new measurement arrives,is used to calibrate the predictor.Due to the cascade structure,the resulting error dynamics system is presented in a non-hybrid form,and accordingly,analyzed in a general sampled-data system framework.Based on the output of the ESO,a continuous ADRC law is then developed.The convergence of the resulting closed-loop system is proved under given conditions.Two numerical simulations demonstrate the effectiveness of the proposed control method.

The Analysis of Systems of Measurement for the Construction of Geometrical Models of the Product

In the present work,the relevant components of the two basic system of measurement are defined through the analysis of existing systems of measurement for geometrical modeling.The major features of such systems related to the ways of formation of the two-dimensional complex drawing of a geometrical image on the basis of laws of projective connections are revealed.Interrelations of the elements of different systems of measurement with various projections of a geometrical image are defined.The relative location of projections of a geometrical image into the constructed two-dimensional complex drawings for various systems of measurement is discussed.The rationale behind a particular arrangement of views in the projective drawing of a product in the analyzed systems of measurement is explained.

Aircraft Observations of Liquid and Ice in Midlatitude Mixed-Phase Clouds

ABSTRACT This paper reports airborne measurements of midlatitude altostratus clouds observed over Zhengzhou, Henan Province, China on 3 March 2007. The case demonstrates mixed-phase conditions at altitudes from 3200 to 4600 m （0°C to -7.6°C）, with liquid water content ranging from 0.01 to 0.09 g m-3. In the observed mixed-phase cloud, liquid water content exhibited a bimodal distribution, whereas the maximum ice particle concentration was located in the middle part of the cloud. The liquid and ice particle data showed significant horizontal variability on the scale of a few hundred meters. The cloud droplet concentration varied greatly over the horizontal sampling area. There was an inverse relationship between the cloud droplet concentration and ice particle concentration. A gamma distribution provided the best description of the cloud droplet spectra. The liquid droplet distributions were found to increase in both size and concentration with altitude. It was inferred from the profile of the spectra parameters that the cloud droplet sizes tend to form a quasi-monodisperse distribution. Ice particle spectra in the cloud were fitted well by an exponential distribution. Finally, a remarkable power law relationship was found between the slope （λ） and intercept （No） parameters of the exponential size distribution.

STABILITY OF LINEAR MEASURE LARGE SCALE SYSTEMS WITH IMPULSIVE EFFECT

Many impulsive phenomena from physics, control theory, and economics urge us toinvestigate measure large scale systems. In this paper, the variation of parameters formulaof the large scale systems containing measures is established. By means of inequality methods and comparison theory, the stability, uniform stability, asymptotic stability, uniformasymptotic stability, and exponential stability properties of linear measure large scale systems are studied.

Smart inverter operation in distribution networks with high penetration of photovoltaic systems

With the growing number and capacity of photovoltaic(PV)installations connected to distribution networks,power quality issues related to voltage regulation are becoming relevant problems for power distribution companies and for PV owners.In many countries,like Italy,this has required the revision of the standards concerning the connection to the public distribution network of distributed renewable generation.The new standards require a flexible operation of generation plants that have to be capable to change the active and reactive power dynamically in function of the network parameters(i.e.frequency and network local voltage)in local control or following external commands.Therefore,this paper investigates the use of smart inverter in a critical PV installation,where relevant voltage fluctuations exist.A case study,with real network parameters monitoring data and measurements,is discussed in the paper with the aim of showing how‘smart’features of new inverters can be implemented to increase PV plant integration in low voltage distribution networks.

Robust Stabilization Control for a Class of Nonlinear Measure Differential Systems with Delay

This paper considers the robust stabilization problem of a class of nonlinear measure differential systems with delay.To eliminate the effect of nonlinear uncertainties on the stability of a closed loop system, a nonlinear controller is employed.In addition, to get the stability result of closed loop dynamics, two novel lemmas are proposed.In our approach, we do not require the assumption that the time varying delay variable γ(t) be restricted by (t)【1 , which is often required in many previous papers (e.g,see).

Observer-Based Robust Control for Measure Differential Systems with Parameter Uncertainty and Time Delay

In this paper, we propose a robust control based on the observer for a class of measure differential systems with time delay. To implement the control, we only need the output signal of the systems. In the finial section, a numerical example is given to illustrate the effectiveness of the proposed scheme.

Global Exponential Stability of Variable Delay and Time－varying Measure Differential Systems with Impulse Effect

This work concerns the stability properties of impulsive solution for a class of variable delay and time-varying measure differential systems. By means of the techniques of constructing broken line function to overcome the difficulties in employing comparison principle and Lyapunov function with discontinuous derivative, some criteria of global exponential asymptotic stability for the system are established. An example is given to illustrate the applicability of results obtained.

Stability of Singular and Time－Delay Measure Differential Large－Scale Systems with Impulse Effects

This paper is devoted to the investigation of stability for singular and time-delay measure differential large scale systems with impulsive solution.With the help of Drazin inverse,the variation of parameters formula of large scale singular systems containing measures and delays is obtained.Employing inequality methods and comparison theory,the stability properties of large scale systems are studied.

VECTOR COMPARISON PRINCIPLE FOR THE STABILITY OF MEASURE DIFFERENTIAL LARGE SCALE SYSTEMS

This paper is devoted to the investigation of Lyapunov's second method for the stability of measure differential large scale systems containing impulses. The vector comparison principle of the stability of measure differential large scale systems is first established. An application of the vector comparison theorem is given to demonstrate the effectiveness of our result.

Extracting inter-area oscillation modes using local measurements and data-driven stochastic subspace technique

In this paper, a data-driven stochastic subspace identification(SSI-DATA) technique is proposed as an advanced stochastic system identification(SSI) to extract the inter-area oscillation modes of a power system from wide-area measurements. For accurate and robust extraction of the modes’ parameters(frequency, damping and mode shape), SSI has already been verified as an effective identification algorithm for output-only modal analysis.The new feature of the proposed SSI-DATA applied to inter-area oscillation modal identification lies in its ability to select the eigenvalue automatically. The effectiveness of the proposed scheme has been fully studied and verified,first using transient stability data generated from the IEEE16-generator 5-area test system, and then using recorded data from an actual event using a Chinese wide-area measurement system(WAMS) in 2004. The results from the simulated and recorded measurements have validated the reliability and applicability of the SSI-DATA technique in power system low frequency oscillation analysis.