非共面四频激光陀螺变温零偏周期性波动

Periodically changed bias over temperature in four-frequency differential laser gyroscopes

非共面四频激光陀螺的零偏随温度周期变化直接影响陀螺性能,提出了一种采用对法拉第旋光元件参数优化有效降低零偏波动幅值的方法。根据非共面四频激光陀螺的振荡光束频率特性,结合腔内旋光元件表面反射光束和散射光束的耦合效应以及旋光元件磁光效应,理论分析确定了导致陀螺变温零偏周期性波动的主要因素。采用对旋光元件楔角、微扰角度以及方位角三项参数的理论计算及仿真分析,确定了参数优化方法和优化验证参数,经验证与理论分析结果一致,有效消除了陀螺变温零偏周期性波动,结合温度补偿模型,实现70°C变温范围内零偏最大变化由1.5(°)/h降低为0.11(°)/h。

The bias of four-frequency differential laser gyroscope changes with temperature periodically, which affects the temperature performance of the gyroscope. In order to depress the fluctuation, a useful Faraday element optimization design is proposed. According to the theory of four-frequency differential laser gyroscope and the coupling effects of reflection and scattering on the surface of Faraday element, the main factor that induces the periodical changes of the bias with temperature in four-frequency laser gyroscopes is analyzed in theory. Theoretical calculation and simulation analysis are made on Faraday element's wedge angle, tilt angle and wedge orientation. The contrast experiments show that the proposed method can effectively eliminate the periodical changes of the bias with temperature. With a temperature compensating model, the maximal change of the bias falls from 1.5 (°)/h to 0.11(°)/h when the variation is within 70. ©, 2015, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.