An input estimation problem to distinguish between an oscillating and a non-oscillating input is considered. This problem can be encountered in marine motion estimation problems. In this article, an iceberg drift problem is considered. Iceberg motion is driven by uncertain wind, mean current and wind induced inertial current. A moving horizon estimator is proposed solving an input estimation problem. In several simulation examples, it is shown that the moving horizon estimator can solve the considered estimation problem and is superior to an extended Kalman filter. In a second part of the paper, the proposed estimation scheme is successfully tested on a real iceberg trajectory with the purpose to capture the forcing of the iceberg correctly and use this to forecast the iceberg drift trajectory. The forecast results with the proposed scheme are promising, since it produces small forecast errors and avoids including highly uncertain current information, which often prohibits successful iceberg drift forecast.
['Leif Erik Andersson', 'Francesco Scibilia', 'Lars Imsland']
Estimation of systems with oscillating inputs - applied to iceberg drift forecast