为了响应国际公约对航海模拟器中的目标船数学模型提出的新要求,解决航海模拟器中目标船数量多且要求仿真速度快的问题,以线性响应型数学模型为基础,融入了舵机伺服系统的性能;船舶转向时速度的下降采用航海实践速降估算公式计算;将风的影响以压舵角的形式加入,并根据实船数据计算出了风压差系数;将浪对输出船首向的影响看成是由白噪声驱动典型海浪频谱引起的;设定流是均匀且恒定的,只影响船位和船速。以一艘实际船舶的数据进行旋回仿真实验,通过实验结果比对,论文给出的目标船简捷型数学模型的模拟结果及精度与实船试验结果符合度较好,但其精度比分离型非线性数学模型精度略差。论文给出的目标船数学模型是以牺牲一定的精度换取简捷的形式,目的是提升航海模拟器中数量众多的目标船的仿真速度。
Responding to the updated requirements of international conventions for mathematical model of target ships and overcoming the difficulty in large number of target ships in a maritime simulator, a linear mathematical model is applied. Combined with rudder servo system, a regression formula is utilized to calculate the decrease of speed of a ship in turning motion. Effect of wind is added in the format of equivalent rudder angle, and a typical wave spectrum driven by white noise is applied to investigate the wave effect on the output of ship heading. Current is assumed uniform and constant, which only affects the position and speed of the ship. The calculation of this simple mathematical model of target ships is basically identical with the test results for a real ship, but slightly worse than the nonlinear mathematical model of MMG. The simple model sacrifices some accuracy for the acceleration of simulation speed in the maritime simulator.