基于4态马尔可夫链的光纤陀螺随机调制

Random modulation for fiber optic gyroscope based on four-states Markov chain

在数字闭环光纤陀螺中,由调制信号引起的电串扰(即调制串扰)会导致零偏稳定性、死区和线性度等指标恶化.为了消除调制串扰信号的影响,提出了基于4态马尔可夫链的随机调制方法.将一个4状态马尔可夫链引入到随机调制中,该马尔可夫链利用正弦函数的周期性和状态转移方向的等概率性,产生出了相互统计独立的调制信号和解调信号,由于解调信号为等概率取值-1,1的零均值随机序列,所以在理想情况下调制信号及电串扰信号和解调信号相关的结果为零.仿真和实验结果表明,基于4态马尔可夫链的随机调制方法对调制串扰信号的抑制可达1×103倍,消除了调制串扰信号对陀螺零偏稳定性、死区和线性度等指标的影响.

Electrical crosstalk from modulation signal deteriorates bias stability, dead band and linearity in digital closed-loop fiber optic gyroscope （ FOG）. A random modulation based on a four-states Markov chain was presented to attenuate the electrical crosstalk. With periodicity of sine function and equiprobability of state transition direction, the four-states Markov chain can generate two signals statistical independently, a demodulation signal and a modulation signal, and the demodulation signal is a zero-mean stochastic sequence with the value of - 1 and 1 equiprobablely. So the electrical crosstalk from the modulation signal can be attenuated via correlation with demodulation signal. The random modulation was implemented by using state machine in field programmed gate array （FPGA）. Simulation and experimental results indicate that the random modulation based on the four-states Markov chain can attenuate the electrical crosstalk from the modulation signal by 1× 10^3 times, and improve bias stability, dead band and linearity of FOG.