捷联式天线稳定平台动力学建模与仿真分析

Dynamics modeling and simulation analyzing for strapdown antenna stable platform

对于体积有限制的战术导弹应用,导引头天线伺服系统的体积受到严格限制,传统的速率陀螺稳定平台的应用受到挑战,为此提出采用捷联稳定方式来解决视线稳定问题.根据弹载捷联式天线平台的结构特点及稳定原理,应用坐标变换方法,完整地建立了两自由度捷联式天线平台的运动学与动力学模型.通过分析平台框架运动学耦合关系,表明捷联稳定方式与速率陀螺稳定方式的基本区别在于信息的获取和控制方式上,速率陀螺稳定方式是一种直接硬件稳定方法,而捷联稳定方式是一种软件补偿方法.在此基础上,对框架动力学耦合特性进行了数值仿真,结果表明:弹体对框架的耦合较强,需要进行弹体解耦,而框架之间的交叉耦合相对较弱,实际设计时可以忽略.所得结果为进一步研究捷联式天线稳定平台提供了理论基础,也为小型化导引头视线稳定平台系统的工程设计提供了一种解决方案.

In space constrained tactical missiles, the size of seeker antenna servomechanism was restricted strictly, and rate gyroscope stabilization platform failed to work very well. The strapdown stabilization technique can be applied to stabilize line-of-sight（LOS）. Based on configuration feature and stabilizing principle, a complete gimbal kinematics and dynamics model of two-degree-of-freedom strapdown antenna platform was achieved via coordinate transformation. The gimbal coupling characteristics was analyzed and simulated. Analysis indicates that main differences between strapdown stabilization platform and rate gyroscope stabilization platform lies in information obtaining and control mode. The rate gyroscope platform gets stability using hardware directly, while strapdown platform bases on software compensation. Simulating also shows that coupling between gimbals and missile body is strong, which need take effect measures to isolate. While cross coupling between outer gimbal and inner gimbal is weak, which can be ignored in practice. Resuhs obtained will be a theoretical foundation for the further study of strapdown antenna platform, and it will be a engineering design suggestion for LOS stabilized system of miniaturized seeker.