光纤陀螺在摇摆状态下的误差特性分析

Error characteristic analysis of FOG on sway base

在海上由于风浪的作用船用光纤陀螺经常处于摇摆状态。在这种运动状态下,光纤陀螺的误差严重制约着捷联惯导系统的导航精度。根据光纤陀螺闭环控制系统的原理,建立了系统模型,并推导出光纤陀螺在摇摆状态下的附加相移误差(实际与理想状态之间闭环控制附加相移的差)表达式和输出误差表达式。从两式可以看出,附加相移误差影响系统的回路平衡时间和输出精度。详细剖析了附加相移误差表达式中各参数所代表的意义以及作用于附加相移误差的途径,并给出减小附加相移误差的方法。仿真和实验结果证明理论分析准确可信,为光纤陀螺动态方面的研究提供了参考。

FOGs（fiber optic gyroscopes） are always in swaying state on the sea because of wind waves.Under this situation,the errors of FOG constrain the precision of strapdown inertial navigation system seriously.A system model is established on the basis of the principle of FOG closed-loop control system.Besides,the additional phase error formula and output error formula are deduced.The two formulas reveal that the additional phase error is one of the key factors that affect the system circuit balance time and output accuracy.The meanings and features of the parameters in the additional phase error formula are analyzed in detail.What＇s more,the methods are also provided to reduce the additional phase error.Simulation and experiment results indicate that the theoretical analysis is reliable,which provides a reference for further study on dynamic characteristics of FOG.