Identification of wave profiles encountered by a ship with no forward speed using Kalman filter technique and validation by tank tests - long-crested irregular wave case

This paper addresses a Kalman filter (KF) technique for identifying wave profiles encountered by a ship with no forward speed from measured ship responses. The KF technique has been applied to a series of tank test results for long-crested irregular head and oblique waves. In the test, an acrylic resin ship model is used. The method is validated by comparing the identified wave profile with reference wave measurement. It is shown that the accuracy of the wave identification can be improved by selecting more appropriate input, and further by combining two input signals. It is also used to estimate non-measured ship responses and its effectiveness is investigated. Finally, it is extensively applied to the future prediction of the wave profile and shown to be effective in predicting the wave profile a few cycles ahead. •A Kalman filter based method to identify wave profiles encountered by a ship from ship response measurement is developed.•A series of tank tests is conducted using an acrylic resin ship model, and the accuracy of the developed method using the Kalman filter technique is verified in long-crested irregular wave case.•The selection and the combination of the ship responses used in the Kalman filter technique to improve the wave identification accuracy are discussed.•The identified waves can be used to estimate the time series of the non-measured ship responses.•Future wave profiles to be encountered by a ship can be estimated up to a few cycles ahead.