@Article{CruzRios:1985:SoDeAu,
               author = "Cruz, Jos{\'e} Jaime and Rios Neto, Atair",
                title = "Software development for automatic ship steering in the presence 
                         of dynamical model uncertainties",
              journal = "Autom{\'a}tica",
                 year = "1985",
               volume = "21",
               number = "4",
                pages = "25",
             keywords = "ENGENHARIA E TECNOLOGIA ESPACIAL, guidance and control of dynamics 
                         systems, ship automatic pilot, adaptive stochastic control.",
             abstract = "The application of stochastic control concepts is considered in 
                         the development of software for automatic ship steering. The 
                         Separation Principle is taken so as to separately treat estimation 
                         and control problems. Extended Kalman filter is used in a 
                         situation where divergence problems could be particulary acute 
                         because of system dynamics modeling uncertainties. To avoid this, 
                         in the estimator model the uncertain unmodeled accelerations are 
                         approximated by first-order Gauss-Markov processes whose states 
                         are estimated together with the original system state variables. 
                         The control objective, primarily related to restricted waters 
                         operation, is to steer the ship along a prescribed geometrical 
                         path by using the rudder as the control element. For the control 
                         problem, a stepwise type control function approximation is taken 
                         and procedure is considered which makes its solution formally 
                         identical to a parameter vector estimation in presence of noise.",
                 issn = "0005-1098",
                label = "11398",
        urlaccessdate = "13 maio 2024"
}