基于滑模干扰观测器的空空导弹三维预测制导律设计

Design of Three-Dimensional Predictive Guidance Law for Air-to-Air Missiles Based on Sliding Mode Disturbance Observer

针对目标大机动情况下制导准确性较差的问题,研究了基于滑模干扰观测器的空空导弹三维预测制导律。利用连续时间非线性预测控制方法,根据导弹当前的状态,选择弹道跟踪误差作为预测性能指标,对其进行在线滚动优化,获得制导指令。同时为了进一步提高导弹制导规律的抗干扰能力,利用滑模干扰观测器对内部不确定性和外部未知干扰进行逼近,并与预测控制方法所得到的制导指令进行综合得到优化制导指令。最后仿真结果表明,所设计的PCG相比于传统的PN,性能有较大的改善,能够实现目标大机动情况下的精确制导,并且所需导弹机动过载小、脱靶量小,具有一定的鲁棒性。

A three-dimensional predictive control guidance law （PCG） is studied,which is based on sliding mode disturbance observer （SMDO） for air-to-air missiles to meet the high precision guidance requirements for high maneuvering target. According to the current state, the trajectory tracking error is treated as the predictive performance index. By applying continuo^-time nonlinear predictive control method, the guid- ance command is obtained via the on-line rolling optimization based on the designed performance index. Meanwhile, the SMDO is designed to estimate the internal uncertainty and the external unknown disturb- ance to improve rejection disturbance ability and an optimal guidance law is obtained by synthesizing predic- tive control （PC） design. The simulation results show that the developed predictive control guidance law is better than proportional navigation （PN） in performance and can track accurately the high maneuvering target. At the same time, it satisfies lower overload requirement of acceleration and has smaller miss distanceand good robustness.