Qiang Shu, Fang Ji, Mingzhi Zhu, Baoxu Wang, Dongge Deng, Fei Yang
Institute of Mechanical Manufacturing Technology, Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China.
Institute of Mechanical Manufacturing Technology, Mianyang 621999, China.
Rev Sci Instrum. 2020 Sep 1;91(9):095005. doi: 10.1063/5.0018011.
In nuclear magnetic resonance gyroscopes (NMRGs), an ambient stray field should be suppressed to maximize performance of the in situ parametrically modulated alkali magnetometer (PMAM). Transfer functions of the PMAM of NMRGs decoupled with lock-in amplifiers are obtained by theoretical and simulation identification. It is found that the frequency bandwidth of the PMAM of NMRGs decoupled by lock-in amplifiers depends largely upon the low-pass filter of the lock-in amplifiers. A dynamic Kalman filter is used to estimate the stray field disturbance that is fed back to field coils to compensate the disturbance in the PMAM. Simulation and experiment results show that the dynamic Kalman filter has adaptiveness to the frequency shift of the nuclear spin precession signal of NMRGs that is quasi-sinusoidal. The dynamic Kalman filter for the PMAM is efficient in suppressing the ambient stray field noise of broad band and low frequency.
在核磁共振陀螺仪（NMRG）中，应抑制环境杂散场，以最大限度地提高原位参数调制碱金属磁力仪（PMAM）的性能。通过理论和仿真识别获得了与锁相放大器解耦的NMRG的PMAM的传递函数。研究发现，由锁相放大器解耦的NMRG的PMAM的频率带宽在很大程度上取决于锁相放大器的低通滤波器。采用动态卡尔曼滤波器估计杂散场干扰，并将其反馈到励磁线圈，以补偿PMAM中的干扰。仿真和实验结果表明，动态卡尔曼滤波器对NMRG的核自旋进动信号的频移具有适应性，该信号为准正弦信号。用于PMAM的动态卡尔曼滤波器在抑制宽带和低频环境杂散场噪声方面是有效的。
