全天时星跟踪器与捷联惯导组成的惯性/天文组合导航系统具有精度高、自主性强等优点，在飞机、无人机、船舶等领域具有广泛的应用前景。组合导航系统长时间工作中力热变化导致安装矩阵漂移进而影响导航系统精度，全天时星跟踪器由于天空光影响视场小，一次只能观测一颗恒星，无法根据一副星图直接进行安装阵估计。提出了一种基于Levenberg-Marquart （L-M）算法的捷联惯性/天文组合导航系统安装阵在线快速高精度估计方法，利用捷联惯导姿态测量值，将不同时刻的观测星矢量转移到同一时刻同一坐标系中，构造多颗观测星的观测矢量误差与导航星矢量最小二乘目标函数，利用自适应步长的L-M算法对其进行迭代求解，实时得到系统安装矩阵的变化量。试验结果表明，使用该方法后星跟踪器在捷联惯导本体坐标系的输出恒星投影矢量精度提升了1倍以上，在线估计时间优于5 ms，满足用户实时性和高精度要求。
The integrated navigation system including an all-time star tracker and a strap-down inertial navigation system with the advantages of high precision and strong autonomy has been extensively applied in fields such as planes, drones and vessels. During the long-term operation of the integrated Inertial Navigation System (INS), the change in force and heat leads to the drift of the installing matrix, affecting the accuracy of the INS. Moreover, the all-time star tracker influenced by the background light in the sky usually has a small Field of View and can only observe one star at a time, therefore unable to directly estimate the installing matrix according to one star chart. A new method is presented for the estimation of attitude matrixes in real time based on the Levernberg-Marquart (L-M) algorithm. Taking advantage of the attitude measurement values of the INS, this approach transfers the observed star vectors at different times to the same time in a unified coordinate system, thereby constructing a cost function relating the observation vector errors of multiple observation stars and the corresponding navigation star vectors in the least square sense. After that, the L-M algorithm with adaptive step size is used for the iterative solution, obtaining the on-line real-time change in the installing matrix. Experimental data show that the pointing accuracy of single stars projecting onto the INS is twice as high as that before using this method and has an estimation time shorter than 5 ms, meeting the engineering requirements for this kind of integrated INS.
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