核磁共振陀螺信号仿真及噪声分析

核磁共振陀螺具有体积小、精度高、功耗低等优势,有望成为下一代惯性导航系统的核心部件,目前正受到人们的广泛关注。比较全面的介绍了核磁共振陀螺的基本理论,在此基础上利用时间离散化方法推导并建立了能够充分考虑核磁共振陀螺系统动态特性的仿真模型。利用该模型研究分析了锁相环相位、磁场、温度以及探测光强在1×10-5均方根幅度下均匀白噪声对陀螺信号的影响,发现它们对角随机游走、零偏不稳定性影响依次减小,且都具有自身独特的频率响应特性。其中,锁相环相位噪声引起的角随机游走与零偏不稳定性分别为5.1985×102(°)/h1/2、3.4593×103(°)/h,而探测光强噪声引起的角随机游走与零偏不稳定性分别为3.1623×10-1(°)/h1/2、4.7603×10-1(°)/h。该研究对深入分析核磁共振陀螺动力学机理、寻找主要噪声来源、提高陀螺性能具有重要意义。

Simulation and Noise Analysis of Nuclear Magnetic Resonance Gyroscope

Nuclear magnetic resonance gyroscope(NMRG) has many advantages, such as small size, high accuracy and low power consumption. It is expected to become the core component of the next generation inertial navigation system and attracts wide attention. In this paper, based on the comprehensively introduction of the NMRG theory, a simulation model which can fully consider the dynamic performance of NMRG is deduced and established by using time discretization technique. The influences of 1×10-5 amplitude white noise from the PPL phase, the magnetic field, the temperature and the detection intensity on the gyroscope signal are analyzed by simulation model. It is found that the influences of white noise from these sources on angle random walk and bias instability decrease in turn, and all of them have their own unique frequency response characteristics. Specifically, the angle random walk and the bias instability from the noise of the PPL phase are 5.1985×102(°)/h1/2 and 3.4593×103(°)/h respectively, while those of the detection intensity are 3.1623×10-1(°)/h1/2 and 4.7603×10-1(°)/h. The results from this work are of great significance to the in-depth analysis of the dynamic mechanism of NMRG, the search for the main noise sources and the improvement of gyroscope performance in future.