考虑自动驾驶仪故障的复合全局滑模制导律

Composite Global Sliding-mode Guidance Law Considering Autopilot Failure

为了提高对低空目标的跟踪精度,需将弹目视线角约束在布儒斯特角附近,以降低多径干扰对雷达导引头探测精度的影响。基于全局滑模控制的原理,设计出一种全局滑模制导律。该制导律可确保在跟踪拦截低空目标的过程中,将弹目视线角约束在布儒斯特角附近。该制导律由于使系统省去了趋近滑模面运动的过程,从而使系统具有全程鲁棒性。针对导弹自动驾驶仪执行制导指令时可能发生的故障问题,设计了一种虚拟指令作为故障扰动的补偿,结合所设计的虚拟指令,设计出一种复合全局滑模制导律。仿真结果表明,该复合制导律可大大提高系统的抗干扰性能,维持系统的稳定性。

In order to improve the precision of tracking low altitude target,the line-of-sight（LOS）angle is needed to be restricted near the Brewster angle to reduce the influence of multipath interference on the detection accuracy of the radar seeker.Based on the principle of global sliding mode control,aglobal sliding-mode guidance law was designed.This guidance law can make the LOS angle restricted near the Brewster angle in the process of tracking and intercepting the low altitude target.The guidance law can eliminate the stage of approaching the sliding surface,which makes the system equipped with robustness in the whole process.Aiming at the possible failure of the missile autopilot executing guidance command,a virtual command was designed to compensate the failure and disturbance.Combining with the designed virtual command,a composite global sliding mode guidance law was designed.The simulation results show that the composite guidance law can greately improve the anti-interference capability and maintain the stability of the system.