翻译为地道的SCI论文标准的英语：为了研究USV运动控制首先需要解决模型建立问题。USV的运动有6个自由度DOF各个方向的运动之间存在着复杂的耦合关系增加了研究的复杂性。本文主要问题是路径跟随控制。因此3个自由度的USV的模型是适用的。

In order to investigate the motion control of unmanned surface vehicles (USVs), it is necessary to address the issue of model establishment first. The motion of USVs involves six degrees of freedom (DOF) with complex coupling relationships between different directions, which increases the complexity of research. The focus of this paper is on path following control, thus a model of USVs with three DOFs is appropriate.