Influence of Ship Motion Nonlinearities on the Course Controller Design

Abstract

Since a ship yard usually provides insufficient data for developing a ship control system, the course and track controller design is based upon a Nomoto model determined with a Clarke estimation of hydrodynamic derivatives. Several ships examined show a poor system performance with a course control derived from these models besides parameter identification problems of adaptive control concepts. Hence, the steering quality of the Mariner class is discussed and linear model parameters are obtained by an interval approximation of Dieudonné's spiral curve in the working range of the rudder. This approach leads to a better controlled nonlinear process.