航天器动力学特性参数在轨辨识技术

Identification system to dynamic characteristics of on-orbit space vehicles

从结构模态参数的可识别性出发,结合结构自由响应识别技术和数字处理技术,开发出大型航天器动力学特征参数在轨辨识系统,包括硬件系统和软件系统,其中软件系统由C++和汇编语言组合编写,系统各部分均模块化,可适用于较复杂的工程任务.在此基础上设计了模拟在轨航天器的试验验证系统,检验辨识算法和设计软件的可靠性以及航天器在轨辨识的实时性.该试验系统包括一个对称的双梁结构,利用对称结构的弱耦合可得到多个密集模态,该结构可模拟大型航天器在太空失重条件下所特有的动力学特征.试验表明系统辨识算法可靠,精度达到设计要求.

Based on the structure identifiability, some frequency-domain technologies using the free dynamic response of the structure were discussed. Including the hardware system which consists of the sensors, The data acquisition equipments, the computers and the identification software which was developed using the C＋＋ language and the assembly language, an identification system which was used to identify dynamic characteristics of an on-orbit space vehicle had been developed, and also a test certification system was designed to verify the reliability of the system and the identification algorithm. The test certification system consisted of a twin-beam which was weakly coupled through a flexible beam between the two beams, and could obtain several concentrated low-frequency modals. The specific dynamic characteristics which the on-orbit space vehicles had under zero-gravity conditions in space could be simulated. The test results show that the system is reliable and the precision of the identification algorithm can meet the design aims.