1 引言 某型导弹红外半实物仿真系统主要由四个分系统——目标模拟分系统、三轴转台分系统、负载模拟系统和仿真计算分系统组成。为了分析研究半实物仿真系统的精度,建立其精确的数学模型是很必要的。数学模型的建立有二个途径:一个是从系统所遵循的物理定理和概念出发,建立数学微分方程式,进行拉氏变换求出传递函数。这样建立的模型, 1 INTRODUCTION The semi-physical simulation system for a certain type of missile infrared semi-physical mainly consists of four sub-systems - target simulation subsystem, triaxial rotary table subsystem, load simulation system and simulation calculation subsystem. In order to analyze the accuracy of the semi-physical simulation system, it is necessary to establish its exact mathematical model. There are two ways to set up the mathematical model: one is to set out the mathematical differential equation from the physical theorems and concepts followed by the system, and the Laplace transform is used to get the transfer function. The model so established,