Analytical modeling of sensor quantization in strapdown inertial navigation error equations
Analytical modeling of sensor quantization in strapdown inertial navigation error equations
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DOI：
10.2514/2.4963
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发表时间：
2002-09-01
影响因子：
2.6
通讯作者：
Savage, PG
中科院分区：
文献类型：
--
作者：
Savage, PG
虽然惯性传感器量化误差通常不被认为是系统不准确的主要原因，但如果没有正确建模，可能会导致对其对惯性导航系统性能影响的错误估计。给出了捷联惯导系统中惯性传感器量化、误差参数传播和测量方程的解析建模方法。用经典的差分误差状态动态格式和离散差分格式推导了误差传播方程。文中说明了如何修改这些方程中的姿态、速度和传感器误差参数，以便能够将传感器量化误差建模为白噪声，并考虑姿态、速度和位置更新频率的差异。离散差分误差方程的形式被用来建立差分误差传播方程中的姿态/速度测量噪声协方差和白量化噪声项的谱密度的值。讨论了如何计算与双速姿态、速度和位置更新算法兼容的微分误差传播方程的量化白噪声谱密度。讨论了白噪声建模近似的有效性极限和降低量化噪声的方法。文中给出了数值算例。
Although generally not considered a major contributor to system inaccuracy, inertial sensor quantization error, if not properly modeled, can lead to erroneously large estimates of its impact on inertial navigation system performance. Analytical methods are described for modeling inertial sensor quantization in strapdown inertial system error parameter propagation and measurement equations. Error propagation equations are derived in classical differential error state dynamic and discrete difference format. It is shown how the attitude, velocity, and sensor error parameters in these equations must be modified to enable proper sensor quantization error modeling as white noise and to account for differences in attitude, velocity, and position update frequencies. The discrete difference error equation form is used to develop values for attitude/velocity measurement noise covariances and for spectral densities of white quantization noise terms in the differential error propagation equations. A general discussion is included of how quantization white noise spectral densities should be computed for the differential error propagation equations for compatibility with two-speed attitude, velocity, and position updating algorithms. Validity limits for white noise modeling approximations and methods for reducing quantization noise are discussed. Numerical examples are provided.