终端末制导中的轨控直接力点火策略

为了提高命中精度,高层大气中防空导弹的终端末制导段常采用轨控直接力实现快响应。在固定的直接力模式下,轨控的点火时间和点火方位直接决定命中精度。目前,常用的点火逻辑由于对预测脱靶量和点火方位估计精度较低使得直接力修正效果未能充分发挥。为此,从3个层面进行点火策略的改进。首先,针对终端末制导过程视线发散的固有特点,通过引入视线角速率变化趋势,提高预测脱靶量估计精度;其次,考虑直接力装置有限的工作时间,通过增加剩余速度修正项,改善直接力修正能力估计精度;第三,将原有基于视线角速率的点火方位策略改进为基于剩余需用过载方向。理论分析表明,相比现有方法,文中提出的改进策略可适当提前点火时间。用不同的机动目标进行六自由度仿真验证,结果表明,新的策略在目标大机动下,可显著降低脱靶量;在小机动下,其性能与原方法相当。

Improved ignition strategy of trajectory control direct force during terminal guidance

In order to improve the hit accuracy,the direct force is usually used in the terminal guidance of air defense missile in the upper atmosphere. Under the work mode with constant direct force,the hit accuracy was directly decided by the time and direc-tion of the ignition.At present,common ignition logic can not give full play to the correction effect due to the low accuracy of miss distance prediction and ignition direction estimation.To this end,the ignition strategy was improved from the following aspects.First, for the inherent characteristics that line of sight( LOS) angle is usually divergent during the terminal guidance,a new method was proposed to improve the accuracy of miss distance prediction by employing the changing trend of LOS angular rate;Second,consider-ing the practical constraints that the working time of the direct device is limited, the estimation accuracy of correction ability of di-rect force was improved by increasing the correction term about residual speed;Third,the original ignition position method using LOS angular rate was modified to use the residual required overload. Theoretical analysis shows that the method proposed can advance the ignition time compared to the traditional method.Six degree of freedom (6-DOF) simulation was carried out using different maneuve-ring targets.The results show that the new method can significantly reduce the miss distance compared to the original method in large target maneuvers,while almost the same in small maneuvering.