谐振式光纤陀螺全数字闭环方案

谐振式光纤陀螺是一种新型的惯性传感仪器,与传统机械陀螺和其他光学陀螺相比具有很多理论上的优势.数字信号处理电路的谐振式光纤陀螺全数字闭环是采用双频率数字锯齿波相位调制技术对光路进行了相应的调制和解调.对光信号中夹杂的大量白噪声以及数字信号处理中由于有限位数的A/D引入的量化噪声进行综合考虑,提出了用比信号带宽高很多的采样率对含有噪声的信号进行过采样,加上后续的数字信号处理,低位数A/D和高位数A/D的检测效果几乎一样.数字调制的精度影响了系统的精度,使用平均法用低位的D/A可以实现很大的调制动态范围.经过基于文中设计的数字系统的实验,得到了和理论仿真类似的解调曲线,证明了文中提出的数字闭环方案的可行性.

All Digital Close-Loop Operation of Resonator Fiber Optic Gyro

Fiber Optic Gyro (FOG) is a new kind of inertial sensor. It has many theoretic advantages over traditional gyros and other optic gyros. This paper presents an all-digital close-loop operation based on DSP circuits, which uses the two-frequency serrodyne modulation to modulate and demodulate the optic route. Considering the white noise mixed in optical signal and the quantization noise from limited bits of A/D, we propose to over-sample the raw signal with the rate of sample which is much higher than its bandwidth. Combined with digital signal processing followed, the detection using A/D with lower bits has nearly the same results as that using A/D with higher bits. The resolution of digital modulation limits the precision of the whole system. Using the average method applied to the D/A,a large dynamic range of modulation can be obtained with lower bits. By the experiment based on the designed digital system, a demodulation curve resembling theoretic simulation is obtained, and the feasibility of this scheme of digital close-loop is proved.