机抖激光陀螺动力学特性研究

Dynamics features of mechanically dithered RLG

在构建激光陀螺捷联系统时,三个激光陀螺安装在同一个基座上。由于三个陀螺振子都在进行高频角振动,激励基座产生耦合振动,造成陀螺是在振动基座环境下工作,引起激光捷联系统的抖动耦合误差,导致系统导航精度下降。采用有限元方法研究了机抖激光陀螺的动力学特性和振动模态,以及机抖激光陀螺的振子抖动对基座的影响和外界激励条件下陀螺的响应。通过压电陶瓷激励下陀螺的频率响应分析,实现了激光陀螺工作状态下的动力学仿真,可以获得陀螺工作时激光陀螺任意位置的动力学响应信息,从而为激光陀螺和基座的结构设计提供评判依据,也为分析激光捷联系统的抖动耦合误差开辟了新途径。

While building the RLG strapdown inertial system,three RLGs are fixed on the same base.As the three RLG whips are angular-oscillated at high frequencies,the base is coupled to vibrate and the RLG is made to work in the oscillating environment.Therefore the RLG strapdown inertial system’s dithered coupled error was caused,which would decrease the navigation accuracy.In this paper,a finite element method is adopted to study on Mechanically Dithered RLG’s dynamic characteristics,vibration mode,the effect that the whips dithering impose on the base as well as its response to exoteric stimulation.By analyzing the RLG’s frequency response excited by piezoelectric ceramic,the dynamics simulation is realized and the dynamics response information at any position when the RLG is working is obtained.It offers a method for structure design of RLG and base,and provides a new approach to analyze dithered coupled error.