捷联式光学导引头视线角速率解耦与估计

Line-of-sight angular rate decoupling and estimation of strapdown optical seeker

为准确估计捷联导引头视线角速率,建立了全捷联导引头数学模型,根据弹目运动相对关系进行视线角速率解耦与估计算法研究。首先,建立了全捷联导引头数学模型,并利用Taylor级数对其进行线性化;接着,根据弹目运动几何学与坐标系相对关系推导视线角速率解耦算法;然后,针对捷联导引头无法直接测量体视线角速率的问题,提出微分+稳态Kalman滤波方法估计体视线角速率;最后,建立视线角速率解耦与估计算法验证系统并进行仿真实验,结果表明:解耦算法绝对误差小于5×10-5rad/s,相对误差小于0.3%,验证了解耦算法的正确性;在包含导引头数学模型的条件下,采用角频率为19.2rad/s的稳态Kalman滤波器,视线角速率估计误差小于4×10-3rad/s,较直接微分方法的估计误差提高近一个量级。视线角速率解耦与估计算法同时能满足制导系统对精度与动态性能的要求。

In order to accurately estimate the line-of-sight （LOS） angular rate of the strapdown seeker, strapdown seeker mathematical model was established, decoupling and estimation algorithm of LOS angular rate was based on the movement of the missile and target relative relationship. Firstly, a mathematical model of the strapdown seeker was established, and the Taylor series was used for its linearization. Secondly, according to the movement of the missile and target geometry and coordinate system relative relationship, the LOS angular rate decoupling algorithm was derived. Strapdown seeker can not directly measure the body line-of-sight （BLOS） angular rate, differential coefficient＋steady-state Kalman filter was proposed to estimate the BLOS angular rate. Finally, LOS angular rate decoupling and estimation algorithm verification system was established and simulation experiment was carried out. The results showed that, the absolute error of decoupling algorithm was less than 5í10-5 rad/s and relative error was less than 0.3%, the correctness of the decoupling algorithm was verified. Under the conditions of containing seeker mathematical model, the steady-state Kalman filter was used by the angular frequency of 19.2 rad/s, LOS angular rate estimation error was less than 4í10-3 rad/s, nearly an order of magnitude was improved than direct differentiation method estimation error. The decoupling and estimation algorithm of the LOS angular rate can at the same time meet the requirements of the guidance system accuracy and dynamic performance.