Linearized controller design for the output probability density functions of non-Gaussian stochastic systems

1 Introduction There are many practical systems that require the control of the shape of the output probability den- sity function rather than just their mean values and variances. These systems are seen in papermaking processes[1,2], chemical engineering, material science, combustion ?ame distribution systems and food pro- cessing industries. For example, in chemical engineer- ing the control of particle size distribution has al- ways been regarded as an important area of research[3], whilst …     

Time-varying controller for known nonlinear dynamic systems with guaranteed stability

This paper presents a solution for the design of a time-varying parametric controller for general nonlinear dynamic systems. The controller can be of any prespecified smooth nonlinear state feedback type so long as it includes a set of time-varying parameters. A Lyapunov function is constructed and used to formulate an effective tuning rule for the involved time-varying parameters. With this selection of the tuning rule, it has been shown that the closed loop system is stable. Two examples are included to illustrate the use of the proposed methods and encouraging results have been obtained.     

A geometric approach to fault detection and isolation for bilinearsystems

In this paper, a geometric approach to the synthesis of a residual generator for fault detection and isolation (FDI) in bilinear systems is considered. A necessary and sufficient condition to solve the so-called fundamental problem of residual generation is obtained. The proposed approach resorts to extensions of the notions of (C, A)-invariant and unobservability subspaces, and it yields a constructive design method     

Monte Carlo simulation of tolerance synthesis equations

This paper presents results on ongoing research aimed at developing an integrated computer-aided tolerancing tool. Starting with explicit tolerance analysis equations used to model the relationship between a part's functional elements and an assembly's functional requirements, the reverse synthesis equations are obtained using a simple Jacobian inversion scheme. The explicit nature of the resulting equations lend themselves to conventional Monte Carlo simulation techniques to determine the percentage of rejects being produced given some statistical distributions of the tolerances appearing in these equations. An example is presented that will provide insight on the merits of the developed method.     

Nutrition rehabilitation of undernourished children utilizing Spiruline and Misola

Background  

Malnutrition constitutes a public health problem throughout the world and particularly in developing countries.     

Disturbance attenuation using proportional integral observers

In this paper, we first propose a proportional integral observer design for single-output uncertain linear systems which permit us to attenuate either measurement noise or modelling errors. We show that, when only sensor noise is present in the system, an integral observer alone suffices to achieve good convergence and filtering properties. On the other hand, when modelling errors and sensor noise are present, we show that, for some classes of linear systems, the proportional integral observer allows us to decouple completely the modelling uncertainties while keeping satisfactory convergence properties. A comparison of the classical proportional observer to the proposed observers are given via academic simulation examples. We next extend the design to the class of single-output uniformly observable non-linear systems. We show through a practical simulation example, dealing with a flexible joint robot, that the non-linear proportional integral has very satisfactory disturbance attenuating properties.     

Observer-based fault diagnosis for a class of non-linear systems Application to a free radical copolymerization reaction

The problem of fault detection and isolation (FDI) is investigated for a class of non-linear systems and applied to the case of the free radical copolymerization of butyl acrylate (BuA) and vinyl acetate (VAc) in an ethyl acetate (EAc) solvent. The approach proposed in this work is based on decoupling techniques using differential geometry theory and observer synthesis for non-linear systems. A design procedure is provided for residual generation. The faults considered in the application are malfunctions of the feed pumps of both monomers and the initiator, and the presence of an inhibitor. A detailed construction of fault detection filters is presented, and their performances in the presence of parameter uncertainties are discussed through some simulations.     

Design of fault diagnosis filters and fault-tolerant control for aclass of nonlinear systems

This paper presents a set of algorithms for fault diagnosis and fault tolerant control strategy for affine nonlinear systems subjected to an unknown time-varying fault vector. First, the design of fault diagnosis filter is performed using nonlinear observer techniques, where the system is decoupled through a nonlinear transformation and an observer is used to generate the required residual signal. By introducing an extra input to the observer, a direct estimation of the time-varying fault is obtained when the residual is controlled, by this extra input, to zero. The stability analysis of this observer is proved and some relevant sufficient conditions are obtained. Using the estimated fault vector, a fault tolerant controller is established which guarantees the stability of the closed loop system. The proposed algorithm is applied to a combined pH and consistency control system of a pilot paper machine, where simulations are performed to show the effectiveness of the proposed approach