一种自适应滤波方法在捷联惯导系统大失准角初始对准中的应用

为了对静基座大失准角捷联惯导系统(SINS)进行初始对准,建立了在静基座下基于四元数的SINS非线性误差模型。该误差模型无需对姿态误差角进行小角度假设。为了在观测噪声方差未知的情况下估计SINS失准角,提出一种在线估计观测噪声方差矩阵的自适应扩展卡尔曼滤波方法。仿真结果表明,该自适应滤波方法能在观测噪声方差未知的情况下有效地对静基座大失准角SINS进行初始对准。

Application of an Adaptive Filter in Initial Alignment of Strapdown Inertial Navigation System with Large Misalignment Errors

A general nonlinear strapdown inertial navigation system(SINS) error propagation model based on quaternion is presented.The error model is used in initial alignment of SINS on static base and does not rely on small misalignment angles assumption.To estimate the misalignment angles of SINS with uncertain measurement noise covariance matrix,an adaptive extended Kalman filtering method is proposed.In the adaptive filtering method,the measurement noise covariance matrix is estimated on-line.Simulation results reveal that without exact measurement noise covariance matrix,the adaptive extended Kalman filtering approach can estimate large initial misalignment angles of SINS efficiently.