光纤陀螺本征频率高精度在线自动跟踪技术研究  

Research on high precision online automatic tracking technology of optical fiber gyroscope

作　　者：代琪 宋凝芳[1] 王夏霄[1] 潘雄[1] 熊瑞 DAI Qi;SONG Ningfang;WANG Xiaxiao;PAN Xiong;XIONG Rui(School of Instrument Science and Optoelectronic Engineering, Beihang University, Beijing 100191 , China)

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《激光杂志》2019年第4期31-35,共5页Laser Journal

摘　　要：光纤陀螺(FOG)在长期贮存后,其光纤环的长度,直径等会受到环境中温度、水汽等的影响,导致其标度因数的偏移。为了实现对高精度光纤陀螺标度因数的补偿,提出了一种基于锯齿波和方波分时复用调制的本征频率在线跟踪方法。对相位调制器叠加2倍调制方波频率的锯齿波,构成分时调制信号,解调时前1/3调制周期提取出的误差信号强度反映锯齿波调制频率偏离2倍本征频率的程度,据此调整调制频率,使锯齿波解调误差信号为零,调制周期后2/3部分用于解调出陀螺输出角速度的值,完成调制频率对本征频率的在线跟踪。采用两路双DCM级联生成两路调制时钟,一路用于驱动陀螺的当前工作,另一路用于准备依据频率跟踪误差调整后的频率,在计算周期的空闲时刻实现切换,解决了频率调整过程中延迟的问题。与传统测量方法相比,该方法分频精度可达0. 1 Hz,跟踪精度可达3 Hz,基本满足高精度光纤陀螺的需求,具有在线自动跟踪本征频率的优点。After long-term storage, the length and diameter of fiber optic gyroscope ring are affected by the temperature and water vapor from surroundings, resulting in a shift in the scale factor. In order to realize the compensation of the high-precision fiber optic gyro scale factor, an on-line tracking method based on sawtooth wave and square wave time division multiplexing modulation is proposed. A sawtooth wave twice the modulation square wave frequency is applied on the phase modulator, forming into a time-division modulation signal, and the error signal intensity extracted in the first 1/3 modulation period reflects the degree to which the sawtooth modulation frequency deviates from twice the eigenfrequency. So adjust the modulation frequency according to the frequency tracking error to make the error signal to zero, and the 2/3 portion of the modulation period is used to demodulate the value of the gyro output angular velocity ,then the on-line tracking of the modulation frequency to the eigenfrequency is completed. Two-way dual DCM cascade is used to generate two modulation clocks, one for driving the current work of the gyro, and the other for preparing the frequency adjusted according to the frequency tracking error, and switching is performed at the idle time of the calculation cycle, and the frequency adjustment process is solved. The problem of delay in frequency in adjustment is solved. Compared with the traditional measurement method, the method has a frequency division accuracy of 0.1 Hz and a tracking accuracy of 3Hz, which basically meets the requirements of high-precision fiber optic gyroscopes, and has the advantages of automatically tracking the eigenfrequency on line.

关 键 词：光纤陀螺 本征频率 在线跟踪 分时复用 双时钟切换 标度因数 

分 类 号：TN929[电子电信—通信与信息系统]