船舶操纵运动建模中的参数可辨识性问题

Parametric identifiability in modeling of ship manoeuvring motion

为保证系统辨识方法应用于船舶操纵运动建模中的有效性,提高建模精度,研究了船舶操纵运动辨识建模中的参数可辨识性问题.从系统辨识原理和船舶操纵运动数学模型结构特点的角度讨论了参数可辨识性的机理,并结合Mariner船试验数据,应用细长体理论分别计算了附加质量和黏性力导数,并与约束模试验结果进行对比.结果表明,附加质量的理论计算结果具有足够的精度,而黏性力导数的计算结果存在较大误差.为此,在应用系统辨识进行船舶操纵运动建模过程中,可将附加质量预先给定以解决参数可辨识性和提高辨识精度.

To guarantee the validity of system identification method applied to the modeling of ship manoeuvring motion, while improving its precision, parametric identifiability was discussed. The mechanism of parametric identifiability was analyzed by discussion of the principle of system identification and the structural characteristics of mathematical model of ship manoeuvring motion. Based on the slender body theory and combining with the model tests of a Mariner Ship, added masses and viscous derivatives were caleulated and compared with that resuits from captive model test respectively. It is demonstrated that the theoretical calculation results of added masses have higher precision than that of viscous derivatives, which show that the added masses can be given in advance in system identification.