Automatic measurement of ship´s attitude by use of servo-type accelerometers

For an accurate measurement of ship´s attitude, the paper develops an automatic measurement system which uses four servo-type accelerometers appropriately located on the ship. Through the location of sensors, the heaving, rolling and pitching signals of the ship are separated from each other with adequate linear combinations of the four sensor outputs. By introducing linear dynamic models of the three signals and using Kalman filters, online measurement of the heaving, rolling and pitching is realized. A bank of Kalman filters are used to overcome an uncertainty of some parameters included in the dynamics