Cecilia F. Morais

• Doctor in Electr. Engineering
• Professor (Assistant) at State University of Campinas (UNICAMP)

Recently, many researchers have tried to answer a question regarding smart cities: how to connect a wide variety of sensors and aggregate the data collected by different technologies related to the Internet of Things (IoT)? Those data are usually gathered and transmitted through WAN (Wide Area Network) or private MPLS (Multi-Protocol Label Switchin...

Recent technological advances in the context of medical cyber-physical systems (MCPS) have enabled the development of the personalization of medical decisions according to the specific needs of the patient applied, for instance, on the optimization of absorption of drugs (pharmacological processes). One of the emerging research themes in this area...

Recent technological advances in the context of medical cyber-physical systems (MCPS) have enabled the development of the personalization of medical decisions according to the specific needs of the patient applied, for instance, on the optimization of absorption of drugs (pharmacological processes). One of the emerging research themes in this area...

This paper proposes a more accurate characterization for the global stability of positive linear systems subject to saturation in the actuators. Exploring the description of saturation by means of the ramp function, that is positive for positive inputs, and the copositivity of quadratic forms, sufficient conditions for the global stability are give...

In a networked control system scenario, the packet dropout is usually modeled by a time-invariant (homogeneous) Markov chain (MC) process. However, from a practical point of view, the probabilities of packet loss can vary in time and/or probability parameter dependency. Therefore, to design a fault detection filter (FDF) implemented in a semi-relia...

The outbreak of coronavirus disease 2019 (Covid-19) accelerated the technological advancement in the context of Education 4.0, since several educational institutions had their face-to-face activities suspended, recommending distance education as a measure to contain the spread of the virus and an alternative for the continuity of their activities....

This paper investigates the problem of control through a Wireless Sensor Network (WSN). Such communication channel is digital (the system to be controlled must be sampled and its mathematical model is discretized) and is also semi-reliable, since it admits the possibility of packet loss (that can be modeled by means of a Markov chain). The aim is t...

This paper addresses the problems of H2 and H∞ control design for continuous-time positive linear systems with uncertain parameters belonging to a polytope. Although it is well known that the optimal H∞ state-feedback gain can be obtained from the bounded real lemma condition with a diagonal Lyapunov matrix without any conservatism for precisely kn...

This work provides a tutorial to model a nonlinear system by means of a set of linear parameter varying (LPV) systems, linearized around equilibrium points in which the control design will be applied. The proposed approach is developed in the coupled tanks system, a nonlinear system that is widely used for educational purposes. Two distinct setting...

This paper proposes a new theoretical stochastic model based on an abstraction of the opportunistic model for opportunistic networks. The model is capable of systematically computing the network parameters, such as the number of possible routes, the probability of successful transmission, the expected number of broadcast transmissions, and the expe...

This paper deals with the problem of control through a semi-reliable communication channel, such as wireless sensor networks (WSN). Particularly, the case investigated is the one where the packet loss rate of the network is time-varying due to, for instance, variation in the distance between the nodes. Considering this practical motivation, the con...

The problems of reduced order $\pmb {\mathcal {H}}_{2}$ and $\pmb {\mathcal {H}}_{\infty }$ positive filter design for positive uncertain discrete-time linear systems are investigated in this letter. Due to the positivity constraint on the matrices of the filter, optimal $\pmb {\mathcal {H}}_{2}$ and $\pmb {\mathcal {H}}_{\infty }$ filters...

This article investigates the problem of designing static output‐feedback controllers for linear parameter‐varying (LPV) discrete‐time systems through the enrichment of the system dynamics. For this purpose, the past values of the measured outputs are included in the control law. Differently from the previous methods from the literature addressing...

This paper investigates the problem of designing H2 robust (or gain-scheduled) static output-feedback (or state-feedback) controllers for discrete-time positive linear systems affected by time-invariant (or time-varying) parameters belonging to a polytope. For this purpose, an iterative procedure based on robust (parameter-dependent) linear matrix...

This paper proposes a new filtering scheme applied to a linearized model of a nonlinear representation for combustion systems, whose parameters are obtained by means of optical sensors. To ensure a robust representation regarding the chosen operation point and external disturbances variations, a linear parameter-varying (LPV) state-space representa...

This article proposes a new strategy to deal with linear parameter‐varying discrete‐time systems, whose time‐varying parameters can be written as solutions (such as exponential, trigonometric, or periodic function) of a linear difference equation (DE). The novelty is to explicitly exploit the precise knowledge of the function describing the time‐va...

This paper introduces a new strategy to improve performance in gain-scheduled control and filtering for LPV systems exploiting statistical information about the time-varying parameters whenever available. The novelty of the technique, named sub-domain optimization heuristic (SDOH), is to design controllers or filters treating robust stability indep...

This paper presents a new technique to design static output-feedback controllers for continuous-time positive uncertain linear systems. The design is performed through an iterative algorithm based on parameter-dependent linear matrix inequality conditions, solved by means of relaxations, with local convergence guaranteed. A qualified feasible solut...

Many biological phenomena are investigated using models formulated in terms on nonlinear differential equations and, in general, the global stability is assured point-to-point by Lyapunov’s theory. However, many times the stability analysis becomes a hard task due to the complex interactions between variables and parameters. Furthermore, when some...

This paper investigates a non-autonomous system that describes a biomathematical model in a salmon farming context. More precisely, we consider two coupled nonlinear differential equations that model the dynamic behavior among aquatic pollution, salmon and microalgae populations. In this maritime habitat, we represent a harmful algal bloom (HAB) du...

This paper investigates the problem of H-2 gain-scheduled design (control and filtering) for LPV systems where the scheduling parameters are affected by additive noises. The purpose is to analyze the impact on the H-2 performance of two models commonly used to model the additive uncertainty, one considering that the bounds for the noise parameters...

This paper investigates a non-autonomous system that describes a biomathematical model in a salmon farming context. More precisely, we consider two coupled nonlinear differential equations that model the dynamic behavior among aquatic pollution, salmon and microalgae populations. In this maritime habitat, we represent a harmful algal bloom (HAB) du...

Many biological phenomena are investigated using models formulated in terms on nonlinear differential equations and, in general, the global stability is assured point-to-point by Lyapunov’s theory. However, many times the stability analysis becomes a hard task due to the complex interactions between variables and parameters. Furthermore, when some...

A class of systems that properly represents several real phenomena is called positive systems, where the state variables, inputs and outputs, can only assume non-negative values. This study field has some open problems since many of the well-establish results for linear systems cannot be directly applied to positive systems. This abstract proproses...

The present work analyzes the feasibility of obtaining a single controller (robust), with theoretical guarantees of stability and performance, valid for a total set of network configurations in designed the controller for an uncertain success probability obtain the protocol for Energy-Efficiency in Networked Control System NCS. In particular, this...

The present work analyzes the feasibility of obtaininga single controller (robust), with theoretical guaranteesofstability and performance, valid for a total set of networkconfigurations (distinct probabilities of successful transmis-sions). The designed controller is robust for an uncertainsuccess probability. This project is based on on a Markovc...

Poster EVIC2018

This paper investigates the problems of stabilization and mixed H-2/H-infinite reduced‐order dynamic output‐feedback control of discrete‐time linear systems. The synthesis conditions are formulated in terms of parameter dependent linear matrix inequalities (LMIs) combined with scalar parameters, dealing with state‐space models where the matrices de...

This paper is concerned with the H2 and H∞ control problems in networked control framework, dealing specifically with cases where the communication between the components is made via a multi-hop network susceptible to packet loss, which is modeled by a Markov chain with Bernoulli distribution. The aim is to investigate the trade-off between the net...

This work investigates the problem of H-infinity state feedback control for linear parameter varying systems whose dynamics is subject to jumps, emphasizing networked control problems in which the parameters and output or input signals may not be available due to packet loss. The networked control problem is formulated in terms of non-homogeneous M...

This paper proposes a complete robust control design procedure for combustion systems, present in a wide range of important applications. Using a non-linear model identified through optical instrumentation, it is proposed a linear model around an operating condition. To ensure robustness with respect to variations on the operation condition and to...

This paper proposes a new approach based on parameter-dependent linear matrix inequality (LMI) conditions associated with a scalar parameter that are sufficient to provide robust H2 and H∞ reduced-order mode-dependent, partially mode-dependent or mode-independent filters for discrete-time Markov jump linear systems (MJLS) with time-invariant uncert...

This paper proposes a new communication protocol for output-feedback control through multi-hop Wireless Sensor Network (WSN). The protocol is based on a Hop-by-Hop transport scheme and is especially devised to simultaneously fulfill two conflicting criteria: the network energy consumption and the stability/performance (in terms of H∞ norm) of the c...

This paper proposes a complete robust control design procedure for combustion systems, present in a wide range of important applications. Using a non-linear model identified through optical instrumentation, it is proposed a linear model around an operating condition. To ensure robustness with respect to variations on the operation condition and to...

This work investigates the problem of H∞ state feedback control for linear parameter varying systems whose dynamics is subject to jumps, emphasizing networked control problems in which the parameters and output or input signals may not be available due to packet loss. The networked control problem is formulated in terms of non-homogeneous Markovian...

This paper proposes new synthesis conditions to design H∞ static output-feedback controllers for discrete-time linear systems affected by time-varying parameters and time-varying delays. The design conditions are provided in terms of sufficient parameter-dependent linear matrix inequalities with a scalar parameter, being capable of synthesizing eit...

This paper is devoted to the problem known as digital redesign, i.e., given a previously designed stabilizing continuous-time controller for a continuous-time plant, synthesize a digital controller that provides the hybrid closed-loop system with output trajectories as similar as possible to the continuous-time ones. To accomplish this goal, two di...

Consider the problem of H-2 filtering of a linear system in a networked control system scenario. More precisely, the communication between the system and the filter is accomplished through a multi-hop network where packet loss, modeled by a Markov chain with a Bernoulli distribution, may occur. The purpose of this paper is to investigate the trade-...

This paper investigates the problem of filtering through a multi-path network, proposing a modeling that minimizes the impact of the packet loss in the performance of the designed filter. The dynamics of the network packet loss is modeled by a discrete-time Markov chain that contains the information about the selection process of the route and the...

The aim of this paper is to investigate the problems of designing H∞ and H2 discrete-time stabilizing controllers for polytopic continuous-time systems through the digital redesign methodology. This technique consists of determining a stabilizing digital gain starting from a predetermined continuous-time controller, such that a performance criterio...

This paper deals with the problem of H∞ reduced order dynamic output feedback control for discrete-time linear systems affected by time-varying parameters with polynomial dependency and norm-bounded terms. The main motivation comes from recent discretization methods for uncertain systems, that produce polynomially parameter-dependent discretized sy...

The aim of this paper is to investigate the problems of H∞ and H2 dynamic output feedback control for continuous-time Markov jump linear systems (MJLS) subject to uncertain transition rates. Synthesis conditions are proposed in terms of parameter-dependent matrix inequalities with a scalar parameter and polynomial variables. The conditions become l...

This paper deals with the problem of robust stability analysis of grid-connected converters with LCL filters controlled through a digital signal processor and subject to uncertain grid inductance. To model the uncertain continuous-time plant and the digital control gain, a discretization procedure, described in terms of a Taylor series expansion, i...

This paper deals with the problem of designing reduced order robust dynamic output feedback controllers for discrete-time Markov jump linear systems (MJLS) with polytopic state space matrices and uncertain transition probabilities. Starting from a full order, mode-dependent and polynomially parameter-dependent dynamic output feedback controller, su...

This paper proposes LMI conditions for H∞ robust state feedback control design of polytopic linear systems with state-multiplicative noise. Considering two distinct domains to deal with uncertainties in the multiplicative noise matrix and in the other matrices of the system, extra slack variables are introduced to provide more flexibility to trade-...

This paper proposes LMI conditions for H∞ robust state feedback control design of polytopic linear systems with state-multiplicative noise. Considering two distinct domains to deal with uncertainties in the multiplicative noise matrix and in the other matrices of the system, extra slack variables are introduced to provide more flexibility to trade-...

This paper is concerned with the problem of H 2 dynamic output feedback control for discrete-time Markov jump linear systems (MJLS) whose transition probability matrix is affected by uncertainties. A two step procedure based on linear matrix inequality (LMI) conditions is used to solve the problem. In the first step, a stabilizing parameter-depende...

Os sistemas clássicos de controle baseiam-se na hipótese de que o canal de comunicação entre os diferentes dispositivos é ideal. Tendo como base essa premissa, torna-se infactível o uso de canais de comunicação sem fio, pois os erros e atrasos inerentes aos sistemas de comunicação wireless são potenciados ao utilizar canais não guiados. Contudo, no...

This paper investigates the problems of H-infinity and H-2 state feedback control design for continuous-time Markov jump linear systems. The matrices of each operation mode are supposed to be uncertain, belonging to a polytope, and the transition rate matrix is considered partly known. By appropriately modeling all the uncertain parameters in terms...

This paper investigates the problem of discretization and digital output feedback control design for continuous-time linear parameter-varying (LPV) systems subject to a time-varying networked-induced delay. The proposed discretization procedure converts a continuous-time LPV system into an equivalent discrete-time LPV system based on an extension o...

This paper investigates the problem of designing robust linear quadratic regulators for uncertain polytopic continuous-time systems over networks subject to delays. The main contribution is to provide a procedure to determine a discrete-time representation of the weighting matrices associated to the quadratic criterion and an accurate discretized m...

This paper addresses the problem of state feedback control design for discrete-time Markov jump linear systems (MJLS) with uncertain transition probability matrix. The main novelty is that, differently from the existing approaches in the literature, the proposed conditions allow the use of polynomially parameter-dependent Lyapunov matrices to certi...

This paper is concerned with the problem of discretization and discrete-time output feedback control design for polytopic continuous-time linear parameter-varying (LPV) systems with network-induced delay. Using a constant sampling period and an extension of the Taylor series expansion applied to the exponential of a parameter-dependent matrix, a di...

This paper is concerned with the H 2 robust filtering problem for discrete-time Markov jump linear systems (MJLS) with transition probability matrix affected by uncer-tainties. Differently from previous approaches in the literature, the proposed strategy presents a systematic way to handle, simultaneously, different types of uncertainties commonly...

This paper investigates the problems of uncertain sampling rate discretisation and the networked control of uncertain time-invariant continuous-time linear systems in polytopic domains. The sampling period is assumed to be unknown but belonging to a given interval. To avoid the difficulty of dealing with the exponential of uncertain matrices, a dis...

This paper addresses the problems of and full-order filter design for continuous-time Markov jump linear systems subject to uncertainties. Different from the available methods in the literature, the main novelty of the proposed approach is the possibility of computing bounds to the and norms of the augmented system composed by the uncertain Markov...

This study is concerned with the problem of H-2 state-feedback control design for discrete-time Markov jump linear systems (MJLS), assuming that the transition probability matrix is not precisely known, but belongs to a polytopic domain, or contains unknown or bounded elements. As a first contribution, the uncertainties of the transition probabilit...

This paper addresses the problem of H ∞ filter design for discrete-time Markov jump linear systems (MJLS) with transition probability matrix affected by uncertainties. The proposed methodology allows to take into account the different types of uncertainties usually adopted in MJLS in a systematic way. New conditions are given for H ∞ filter design...

This paper investigates the problem of ℋ∞ static output feedback control design for discrete-time Markov jump linear systems (MJLS), assuming that the transition probability matrix is not precisely known, but affected by different classes of uncertainties: polytopic, bounded or completely unknown elements. All types of uncertainties are modeled thr...

This paper proposes a new discretization technique with constant sampling time for time-invariant systems with uncertain parameters belonging to a polytopic domain. The aim is to provide an equivalent discrete-time representation of the continuous-time system whose ℋ2 guaranteed cost is an upper bound for the ℋ2 worst case norm of the original syst...

This paper addresses the problem of constant sampling discretization of uncertain time-invariant continuous-time linear systems in polytopic domains. To circumvent the difficulty of dealing with the exponential of uncertain matrices, a new discretization method, based on Taylor series expansion, is proposed. The resulting discrete-time uncertain sy...

This study is concerned with the problem of ℋ2 state-feedback control design for discrete-time Markov jump linear systems (MJLS), assuming that the transition probability matrix is not precisely known, but belongs to a polytopic domain, or contains unknown or bounded elements. As a first contribution, the uncertainties of the transition probability...

This paper proposes an improved approach to ℋ2 and ℋ∞ robust state feedback control design for discrete-time polytopic time-invariant linear systems based on Linear Matrix Inequalities (LMIs) with a scalar parameter. The synthesis conditions, that depend on a real parameter lying in the interval (-1,1), become LMIs for fixed values of the scalar, r...

An improved linear matrix inequality (LMI) approach is proposed to deal with the problems of stability, mode-dependent and mode-independent stabilization of discrete-time Markov jump linear systems (MJLS) with partly unknown transition probability matrix. As a first contribution, the uncertain parameters of the transition probability matrix are mod...

The impact of motor starting on power quality can be assessed using numerous and complex computer dynamic si-mulation studies. However, utility engineers have become more interested in practical techniques that enable fast and reliable as-sessment of new motor installation proposals, so that studies of several cases can be conducted. In this contex...