Experimental Validation of a Marine Propeller Thrust Estimation Scheme

A thrust estimation scheme for a marine propeller has been experimentally tested in waves and with a device that simulates the in uence of a vessel hull. The scheme is formed by a nonlinear propeller torque observer and a mapping to generate the thrust from the observed torque. The mapping includes the estimation of the advance number. This is utilized to improve the performance when the propeller is lightly loaded. The advance speed is assumed to be unknown, and only measurements of shaft speed and motor torque have been used. Accurate results have been obtained in experimental tests.