空空导弹变结构末制导律研究

A Studty of Terminal Variable Structure Guidance Law of Air-to-Air Missile

在空空导弹末制导段中,为了提高对目标未知逃逸机动的鲁棒性,提出了变结构末制导律。以零化视线角速度为切换面设计了末制导段针对目标逃逸的变结构制导律,研究了将目标机动作为干扰情况下变结构制导律满足稳定性的条件。针对变结构制导律中滑动模态的颤振问题,提出用一次函数取代传统变结构制导律中的符号函数,从而对变结构制导律加以改进而改善由于符号函数而产生的滑动模态的振颤现象。仿真结果表明,提出的经过改进的变结构制导律结构简单,易于实现,且具有良好的导引精度。

For the case of the escape maneuver of the target in the terminal phase of the missile, the performance of a guidance law will always be degraded for high - g maneuvering targets when the target acceleration measurements can nor be obtained. To solve the problem, a guidance law of variable structure, which is based on the slip plane of zeroing LOS （Line of Sight） angle velocity, is presented in this paper. It is proved that VSS guidance has superior robustness for the target whose acceleration is unknown. However, in the conventional variable structure guidance law the chattering of line - of - sight angular velocity always happens so that the precision of the guidance law may be depressed. In this paper, an once function is introduced to improve the variable structure guidance law so that the chattering can be depressed. The simulation results show that the improved guidance law is easy to be applied and has fine guidance precision.