基于预测碰撞点的剩余飞行时间估计方法

分别针对顺轨与逆轨拦截飞行轨迹的特点，设计了相应的剩余飞行时间（TGO）估计方法。该方法通过对弹目碰撞点的预测，降低了发射条件差异对TGO估计精度的影响。首先对线性比例导引运动方程进行变形，得到拦截弹飞行轨迹关于弹目距离的一阶微分方程，基于预测碰撞点，对不同初始发射角造成的积分结果误差进行修正，得出了2种拦截模式下的TGO解析表达式。通过与3种现有估计方法对比分析，验证了提出方法的实时性和估计精度，且能够优化制导性能。 

Method of time-to-go estimation based on predicted crack point

Aimed at the different characters of the head-pursuit and head-on interception flight trajectory, the time-to-go (TGO) estimation methods are designed. According to the prediction of the crack point for the interceptor and target, the influence of different launch conditions on the precision of TGO estimation is decreased. At first, the linear proportional navigation motion equation is transformed, and the first order differential equation about the distance between interceptor and target is obtained. Based on the predicted crack point, the error for the integration result caused by the different initial launch angles is corrected. Then the TGO analytical expressions of two interception models are obtained. Compared with the existing three methods, the simulation result verifies the real time performance and the estimation precision of the proposed method which is able to optimize the guidance performance effectively.