Thrust Response and Polynomial Drag Characterization of a USV with Electric Motors

This work describes a methodology to estimate the linear and quadratic drag parameters of a catamaran used as an autonomous platform, while using this information to characterize the generated propulsive forces as a function of the control input, of utmost importance in further motion control implementations on the vehicle. The approach consists of a combination of empirical system identification tests with an uncoupled version of the equation of motion in the surge direction, in order to estimate the total thrust generated. Estimations of drag coefficients and thrust are incorporated in a dynamic model used for simulations to validate the results against test data for different values of thrust within the actual operational range of the vehicle.