Modelling of a High Speed Craft by a Non-Linear Least Squares Method with Constraints

Abstract A non linear least squares method with constraints have been tried. However, the extra complexity associated with non-linear systems, with constrains and no initial information of model structure, means that exhaustive search is not always feasible. In these cases genetic identification strategy can be used to obtain initial values. On the other hand, a trend in the area of system identification is to try to model the system uncertainties to fit the available analysis and design tools of robust control. The method described is applied to obtain the interval model of the vertical dynamic of a high speed craft for different speed, and comparative results obtained with the mathematical model and with a scaled model in a towing tank are showed.