AgradecimentosExpressarei em poucas linhas minha gratidão àqueles que de alguma forma estiveram presentes e que muito me ajudaram em meu caminho até aqui.À Deus, pela constante e amorosa presença.À minha família, que sempre me deu suporte de forma incondicional em todos os aspectos possíveis durante meus estudos.À Letricia e Luciano, pela lealdade, amizade e atenção.
AbstractThis work studies linear filtering for discrete-time systems with Markov jump parameters. We introduce a notion of average reachability for these systems and present a set of matrices playing the role of reachability matrices, in the sense that their rank is full if and only if the system is average reachable. Reachability is also a sufficient condition for the second moment of the system to be positive. Uniform positiveness of the error covariance matrix is studied for general (possibly non-markovian) linear estimators, relying on the state second moment positiveness. Stability of linear markovian estimators is also addressed, allowing to show that markovian estimators are stable whenever the system is reachable, with the interpretation that the error covariance remains bounded in the presence of error of any magnitude in the model of the noise, which is a relevant feature for applications. Numerical examples are included.