Comparison of non linear identification methods for underwater vehicles

This paper deals with the identification of non linear multivariable models of underwater vehicles. For this purpose two different, recently proposed methods, are presented and compared from a methodological point of view. The first method is based on a Lyapunov approach, while the second one is based on the least squares approach. The two considered methods operate in the continuous time domain and can be applied to non linear models that are linear with respect to the unknown parameter vector. After an introduction, where the role of identification methods in the area of guidance and control of underwater vehicles is outlined, the mathematical models that are generally used for describing the dynamics of underwater vehicles are concisely presented. The main features of the two identification methods are then discussed and compared.