Pattern Recognition of Pitch Motion for A New High Speed Gliding-hydrofoil Craft and Its Method

Gao Shasha, Yang Songlin, Liu Man, Shi Yan, Cao Zhiwei

In this paper, a series of still water free decay experiments were carried out on a gliding-hydrofoil craft. By establishing the mathematical model of pitch motion mode, and based on system identification theory and genetic algorithm, the system identification software was written in C# language. (1) A mathematical model of 3 kinds of pitch motion was established. The pitch motion of three different drafts and different initial pitch angles were identified and calculated. The conclusion is that the fitting effect of the equation 1 is the best; (2) By calculating the angular velocity forecasting values for various operating conditions, the errors between the experimental values and the fitted values were analysed. It is found that the consistency of the forecast value and the test result is good, which proves the reliability of the system identification software; (3) Based on the identification results, the variation of each hydrodynamic torque coefficient with draft and initial pitch angle analysed. The analysis results and methods can provide a reference for sea-keeping research of such unmanned craft, and provide important technical support for subsequent optimization design of craft type.

https://dx.doi.org/10.31873/IJEAS.5.7.17