椭圆锥动效应对机械抖动激光陀螺振动特性的影响

Influence of elliptical coning motion effect on mechanically dithered RLG vibration performance

对机械抖动激光陀螺的振动特性进行了理论分析,得到了水平振动下陀螺测量敏感轴存在椭圆锥动效应,并得出了该锥动效应引起的陀螺输入角速度表达式。利用有限元分析软件ANSYS,对机械抖动激光陀螺进行了随机振动分析,仿真证实了锥动效应的存在,并采用物理方法试验验证了椭圆圆锥运动的存在及其锥动幅角的大小。通过数值仿真与分析,指出了减小锥动效应,提高陀螺振动性能的有效措施是增大抖动偏频机构的横向抗弯刚度。改进设计的试验结果表明,采用大横向抗弯刚度的新型抖动偏频机构使陀螺的抗振性能提高了4倍多。

Theoretical analysis is made on the vibration performances of mechanically dithered RLG, which shows that the sensitive axis of gyro system under horizontal vibration have elliptical coning effect. Then the expression of equivalent gyro bias produced by the coning motion is derived. The random vibration analysis of mechanically dithered RLG is performed by the finite element software ANSYS, which proves the existence of coning motion effect. Furthermore, the existence of coning motion effect and the magnitude of coning motion argument are proved by physical tests. Numerical calculation shows that the coning motion effect seriously influences the RLG vibration performance, and the method to improve the vibration performance by increasing cross flexural rigidity is put forward, which is useful to improve the anti-vibration design of mechanically dithered RLG. Test results of the improved design show that, by increasing cross flexural rigidity, the vibration result is improved by four times.