【作者】 张俊；

【导师】 周柯江；

【作者基本信息】 浙江大学 ， 工程硕士（专业学位）， 2018， 硕士

【摘要】 光纤陀螺是一种基于Sagnac效应,用于测量角速度的惯性敏感器件。光纤陀螺分为干涉式光纤陀螺和谐振式光纤陀螺。其中,干涉式光纤陀螺的已广泛应用于各种场合,而谐振式光纤陀螺仍处于实验室研究阶段。本文针对光纤陀螺的信号处理研究分成两个部分。第一部分针对干涉式闭环光纤陀螺的信号处理研究,研究内容为使用PIN光电二极管和超高FET运放搭建光电探测电路代替传统的集成PIN-FET器件,包括采用跨阻放大器和积分器两种方案。第二部分设计并实现一种谐振式陀螺单闭环信号处理电路方案,该方案采用低频正弦波调制和模拟器件解调,具有较高的响应速度。文中首先介绍了两种光纤陀螺的检测方案和使用的光学器件;其次,介绍了光电探测电路设计原理和测试结果;之后,分析了干涉式光纤陀螺信号处理电路的各个模块,并对设计的样机进行测试。最后,分析了谐振式光纤陀螺的闭合控制原理和信号处理电路的各个模块,并对设计的方案样机性能进行测试。实验结果如下。(1)采用高增益跨阻放大器搭建的光电探测电路与传统集成PIN-FET相比,电路的性能得到提升,且成本仅为后者的10%;(2)在常温下,将光电探测电路应用于干涉式光纤陀螺,与原方案相比功耗降低200mW,前放模块所占电路面积减少40%,陀螺的零偏为-7.88°/h(含杭州地区地球自转投影量-7.56°/h),零偏不稳定性为0.027°/h,随机游走系数约为0.0023°/(?);(3)初步实现了采用模拟积分器形式设计的光电探测电路,但未进行样机实验;(4)所实现的谐振式光纤陀螺信号处理电路能够输出信噪比为72.5dB的正弦波调制信号,同时能够实现对调制信号的检测和解调,通过调节PI控制参数使系统稳定,并进行了模拟转速实验,在一定范围内,测量结果与谐振点频移量呈线性相关。更多还原

【Abstract】 Fiber-optic gyroscope(FOG)is an inertial sensor to measure the rotation rate,which is based on Sagnac effect.FOG can be classified into two types:resonator fiber-optic gyros(RFOGs)and interferometric fiber-optic gyros(IFOGs).IFOGs have been widely used in many applications,but RFOGs are still in an experimental phase.In this paper,the research on the signal processing of FOGs is presented.It is primarily divided into two parts.In the previous part of the paper,we mainly treat some improvements in signal processing of digital closed-loop IFOGs.They consist of that:(1)a PIN photodectector and a FET OP Amp are exploited to replace the traditional integrated PIN-FET device.In the latter part,a new signal processing scheme on digital closed-loop RFOGs is proposed.In the novel proposal,we adopt the low frequency sin wave modulation and analog device hardware demodulation techniques,which have the advantage of high response speed.This paper firstly introduce some usual optical devices and two signal detection schemes in FOGs.The related design principle of photodetectors’ circuits and test results are shown afterwards.Then,each module in the signal processing circuit of IFOGs is further analyzed and the novel prototype is tested.At last,each module in the signal processing circuit of RFOGs is also analyzed and the performance of the prototype is also proved.The experimental results are shown as fellow:(1)Compared with the traditional integrated PIN-FET device,the performance of the photodetector comprised of high-gain trans resistance amplifier is better.What’s more,the corresponding cost has fallen by about 90 percent.(2)At room temperature,test results of the IFOG applying the photodetector demonstrate that the zero bias is-7.880/h(including the projection-7.560/h of the earth’s rotation in Hangzhou),the bias drift is 0.027°/h and the angular random walk is about 0.00230°/(?).Compared with the original scheme,the power cost can drop 200mW and the circuit area of the pre-amplifier module can fall by about 40 percent.(3)The photodetector designed by analog integrator has been implemented initially,but the prototype has not been tested.(4)A sin wave modulation signal whose signal-to-noise(SNR)ratio is about 72.5dB can be received in the signal processing circuit of RFOGs.And the processing circuit can realize the detection and demodulation of the signal.By adjusting PI control parameter to stabilize the system,we conduct the simulated rotational rate experiment.The result indicates that the measured values are linearly correlated with the frequency shift of resonance points within certain range.更多还原