Application of covariance analysis method in design of modulated inertial navigation systems

协方差分析法在调制型惯导系统设计中的应用

¹ School of Automation, Northwestern Polytechnical University, Xi'an 710072, China
² Unit 93170 of the PLA, Xi'an 710000, China

Received: 8 January 2023

Abstract

Error analysis of inertial navigation systems is one of the important tasks in inertial navigation research. Through error analysis, the contribution of each error in the system to the total error can be obtained. This work is particularly important in the rotary modulation inertial navigation system, because it is necessary to evaluate the suppression effect of the rotation strategy on various error sources through error analysis. Firstly, a state space model of the error has been established based on the system error model, and the total navigation error is divided into linear combinations of various error factors through recursion and decomposition. The derived covariance update equation can be used to quickly and accurately obtain the contribution of various errors including initial error and device error to the total system error. Simulation results of strapdown, single-axis and two-axis modulation systems verifies that the error propagation rules calculated by the proposed method are in agreement with the known conclusions. Simulation of different modulation strategies shows that the proposed method is fast and intuitive in evaluating rotation strategies.

摘要

对惯导系统进行误差分析是惯导研究的重要工作之一, 通过误差分析可以获得系统中每个误差项对总误差的贡献。在旋转调制惯导系统中该项工作尤为重要, 需要通过误差分析评判旋转策略对各项误差源的抑制效果。根据系统误差模型建立了误差的状态空间模型, 并通过递推和分解将导航总误差分为各种不同误差因素的线性组合。利用推导出的协方差更新方程可以较为快捷准确地获得包含初始误差及器件误差各项误差对总误差的贡献。通过对捷联、单轴以及双轴调制系统的仿真分析验证了所推导分析方法计算出的误差传播规律与已知结论相符, 并通过不同的调制策略仿真展示了这种分析方法在评估旋转策略时的快捷性和直观性。