Theoretical-applied aspects of the composition of regression models for combined propulsion complexes based on data of experimental research

Based on the study into internal properties of components of the ship power plants (SPP) in the combined propulsion complexes (CPC) and considering special features in the construction of equations that characterize energy processes in the specific SPP of the particular CPC, we developed the principles of constructing their regression models according to data from experimental research. The function is defined that connects input variables and the output variable based on data of the experiment with the certain number of common observations of the input and output parameters. The check for adequacy of the obtained model was performed according to the experimental data.

Such studies are necessary in order to develop specialized software modeling tools that are used when designing CPC SPP whose structure may vary in certain specified operational limits and situational factors. Similar empirical models also make it possible to improve simulation modeling algorithms involving the use of statistical tests and construction of CPC SPP models based on experimental data.

As the result of present research, according to data obtained in the course of experiment, which contained 14 joint observations of the input and output parametric coordinates of the thruster drives (TDs) of CPC of the ship that operates under dynamic positioning mode, we estimated variation in the coefficients of regression equation and determined coefficients b0=0.4527; b1=–0.1126; b2=0.0848; b3=–0.0277; b4=0.0856, which refine the structure of regression model of SPP of CPC. For different levels of significance and degrees of freedom, the Student's t-criterion was computed for significance level α=0.06 and for the number of degrees of freedom 30 fy=30t(0.06; 30)=t(0.06; 2)=4.823, as well as the Fisher’s F-criterion Fe (0.06; 12; 2)=5.43, on the basis of which the conclusion was made that confirms adequacy of the obtained model according to the experimental tests.

Based on the constructed regression model, it is possible to adjust the position of CPC TD relative to each other and to the diametrical plane of the ship, as well as directions of TD rotation in the process of optimization of parameters of physical models of control systems of TD electric engines.