Model-based networked control for finite-time stability of nonlinear systems: the stochastic case

In this paper we analyze model-based networked control systems for a discrete-time nonlinear plant model, operating in the presence of stochastic dropout of state observations. The dropout is modeled as a Markov chain, and sufficient conditions for finite-time stochastic stability are provided using the stochastic version of Lyapunov second method. In a companion paper we model the dropout as a deterministic sequence

Finite time stability design via feedback linearization

A new nonlinear design technique for Finite-Time Stability for a class of nonlinear systems is developed using feedback linearization. Moreover, a new concept, namely the Finite-Time Contractive Stability with fixed settling time is introduced, giving sufficient conditions for analysis and design. An example illustrates the theoretical results

Finite-time stability of discrete-time nonlinear systems: analysis and design

Finite-time stability of nonlinear discrete-time systems is studied. Some new analysis results are developed and applied to controller design

The Development of a Novel Cu-Mn Oxygen Carrier for the Chemical Looping Gasification of Biomass

Circulating fluidized bed technology applied to combustion processes in which oxygen and fuel are fed into separate reactors is referred to as Chemical Looping Combustion. Typically, oxygen reacts with a reduced metal (-oxide), then it is transferred to a second vessel where the metal oxide is reduced by a hydrocarbon. In chemical looping gasification, a fuel is contacted indirectly by oxygen and/or steam again with a metal oxide shuttling between two vessels reducing the contact between fuel and air. In this case, a concentrated stream of syngas exits the fuel reactor undiluted by nitrogen. The objective of this study is to develop a solids substrate capable of releasing oxygen in the fuel reactor. A bimetallic Cu-Mn oxygen carrier was synthesized by incipient wetness impregnation at ambient conditions over Al2O3. Copper-based oxygen carriers have superior oxygen transfer capacity and environmental and economical characteristics compared to nickel, iron and cobalt, but the operating temperatures are limited due to the low melting point of the metallic copper. Adding manganese to copper minimizes the formation of copper aluminate. Moreover, it inhibits copper agglomeration and carbon deposition. The developed oxygen carriers were characterized by BET, XRD and SEM analyzers. Also, oxygen transfer capacities of particles were tested using thermo gravimetric analysis (TGA). Results indicate that Cu-Mn is a superior carrier, which is suitable for the separation of oxygen in a chemical looping process. Also, adding manganese to copper allows working at high temperatures and improves the reactivity of copper

CONTINUOUS AND DISCRETE TIME SPR DESIGN USING FEEDBACK

This paper presents necessary and sufficient conditions for the existence of a feedback compensator that will render a given continuous-time or discrete-time linear system SPR. When these conditions hold, the controller is explicitly found

Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes

We report on test results of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3-70 GeV/c for the BTeV experiment

Stability and finite-time stability analysis of discrete-time nonlinear networked control systems

In this paper we present an approach to model networked control systems with a discrete-time nonlinear plant, operating in the presence of arbitrary but finite data dropout of state observations. Sufficient conditions for stability of the global system and finite-time stability over transmission intervals are provided

FIBRE-OPTIC PROBE FOR THE SIMULTANEOUS MEASUREMENT OF GASEOUS SPECIES COMPOSITION AND SOLIDS VOLUME FRACTION

A novel infrared fibre-optic probe was developed to measure quantitatively and simultaneously solids volume fraction (1-E) and gaseous species composition (Yi) in a gas/solid fluidized bed. The fibre-optic probe was used with a FT-IR spectrometer to perform real-time and in-situ measurements of absorbance in the fluidized bed. The effect of (1-E) and Yi on the absorbance spectra were additive and could be independently calibrated. To calibrate the probe, fuel mole fractions and (1-E) were varied between 1.8 - 10.1 mol% and 0 - 0.45, respectively. A proof of concept for a novel application in fluidized beds was completed: the fibre-optic probe was used to measure the molar fraction of a tracer gas inside the emulsion and bubble phases during gas tracer experiments

Toward “smart tubes” using iterative learning control

In the paper, we present our progress toward designing a “smart” high-peak power microwave (HPM) tube. We use iterative learning control (ILC) methodologies in order to control a repetitively pulsed high-power backward-wave oscillator (BWO). The learning-control algorithm is used to drive the error between the actual output and its desired value to zero. The desired output may be a given power level, a given frequency, or a combination of both. The learning-control methodology is then verified in simulation. This methodology is applicable to a wide variety of HPM sources

FLUIDIZED BED COMBUSTION OF C1-C4 N-ALKANES

The non-premixed combustion of C1 to C4 n-alkanes was investigated inside a bubbling fluidized bed of inert sand particles at intermediate temperatures: 923 K (650oC) ≤ TB ≤ 1123 K (850oC). Lower (T1) and upper (T2) critical transition bed temperatures were measured for ethane, propane and n-butane as 923 K (650oC) and 1073 K (800oC), respectively. The values for methane were significantly higher with T1 = 1023 K (750oC) and T2 \u3e 1123 K (850oC). Alkane conversion was accurately modeled with first-order kinetics and C2 to C4 n-alkanes combustion rates were characterized by a uniform Arrhenius expression: (. The reaction rate of methane was significantly slower with : (