基于对称方波调制的光纤陀螺本征频率自动测试方法  

Auto-test Method for FOG Eigenfrequency Based on Symmetric Square Wave Modulation

作　　者：周友伟[1] 刘铁根[1] 李茂春[1] 侯丽丽[1] 姚晓天[1] 

机构地区：[1]天津大学精仪学院,光电信息技术科学教育部重点实验室,天津300072

出　　处：《激光与红外》2008年第7期676-679,共4页Laser & Infrared

摘　　要：从光纤陀螺的调制原理出发,采用频率为光纤环本征频率的1/2的对称方波对Y波导进行调制,分析光纤陀螺的输出信号,得到输出的方波信号的占空比与调制频率的对应关系,通过数据采集卡将占空比转化为方波上下峰值点数差的问题,并以此点数差作为反馈量调节对Y波导的调制频率实现对本征频率的自动锁定。该方法已在工程实践中得到应用,试验结果表明该测试方法可在几秒中之内完成而且测试精度可达0.01kHz。与已有的测量方法相比,基于对称方波调制的测试方法具有更高的精度、高速、数字化和易于实现自动测量。A new approach was presented to solve the problem of fiber optic gyro（FOG） eigenfrequency auto measuring. Based on the modulation-demodulation theory, the paper adopted symmetric square-wave to modulate Y-waveguide and analyze the demodulated signal. Then the relationship between the modulation frequency and duty cycle of demodulated signal is got. To the duty cycle as a feedback to adjust modulation frequency,when the duty cycle is 50% the modulation frequency is half of eigenfrequency. And this method is applied in our test system, which shows that accuracy is about 0.01kHz, and auto-test can finished in several seconds. Compared with existing methods this auto-test method is more accurate, rapid and easy to implement automatic digital measurement.

关 键 词：光纤陀螺 本征频率 对称方波调制 占空比 

分 类 号：TM935.1[电气工程—电力电子与电力传动]