复用双轴光纤陀螺仪

Multiplexed double-axis fiber optic gyroscope

为了降低光纤陀螺的成本,提出一种采用时分复用方法的干涉型双轴光纤陀螺仪方案.通过在单轴光纤陀螺结构中增加2个耦合器和1个光纤环,得到复用双轴光纤陀螺的结构.由于不同长度光纤环的渡越时间不同,在合理设计2个光纤环长度比的条件下可应用时延差分调制方法,可以从调制周期中不同阶段的干涉强度信号中分别得到2个轴的角速率信息.基于上述方案制作了实验样机,对系统的功能和静态性能进行验证测试,结果表明:该方案样机角度随机游走优于0.05°/h1/2,零偏稳定性优于0.85°/h.此双轴系统将每轴角速率的成本约降低了原来的50%.

A multiplexed interferential fiber optic gyroscope（IFOG）based on time division multiplexing was proposed to reduce the cost of fiber optic gyroscopes.The double-axis IFOG was built by adding two extra couplers and one fiber coil to one single axis fiber optic gyroscope.Due to the transition time difference between two fiber coils with different lengths,by setting proper coil length ratio,the angular speed information of each axis could be deduced by detecting the intensity of interference light signal of different phase in a modulation period,combining the time delayed differential modulation characteristic of sagnac interferometer.A experimental model of this method was built using open loop control.The function of getting the angular speed information of two axes separately was tested.The static performance test results show that the model has a performance better than a random angular walk coefficient of 0.05°/h1/2 and a bias instability of 0.85°/h.The cost of this double axis IFOG is nearly the same as a single axis one,therefore the cost for getting the angular speed of one axis is reduced to nearly 50%.