S. Vakili
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3 records found
1
Nonlinear Parameter Estimators in Dynamic Environments
A Bayesian Approach
The work begins with a maximum a posteriori (MAP) estimator for identifying an unknown output map, formulated as a linear time-varying (LTV) observation-model identification problem. In this setting, the MAP estimation problem is posed over the entire state-parameter trajectory and shown to be non-convex. A semidefinite-programming (SDP) relaxation based on linear matrix inequalities (LMIs) is then derived to obtain a conservative but tractable approximation, whose solution serves as a warm start for quasi-Newton re!nement. Numerical experiments validate the efficacy of the proposed method in terms of estimation accuracy and computational efficiency.... ...
The work begins with a maximum a posteriori (MAP) estimator for identifying an unknown output map, formulated as a linear time-varying (LTV) observation-model identification problem. In this setting, the MAP estimation problem is posed over the entire state-parameter trajectory and shown to be non-convex. A semidefinite-programming (SDP) relaxation based on linear matrix inequalities (LMIs) is then derived to obtain a conservative but tractable approximation, whose solution serves as a warm start for quasi-Newton re!nement. Numerical experiments validate the efficacy of the proposed method in terms of estimation accuracy and computational efficiency....
Linear Time-Varying Parameter Estimation
Maximum A Posteriori Approach via Semidefinite Programming
We study the problem of identifying a linear time-varying output map from measurements and linear time-varying system states, which are perturbed with Gaussian observation noise and process uncertainty, respectively. Employing a stochastic model as prior knowledge for the parameters of the unknown output map, we reconstruct their estimates from input/output pairs via a Bayesian approach to optimize the posterior probability density of the output map parameters. The resulting problem is a non-convex optimization, for which we propose a tractable linear matrix inequalities approximation to warm-start a first-order subsequent method. The efficacy of our algorithm is shown experimentally against classical Expectation Maximization and Dual Kalman Smoother approaches.