带落角约束的自适应滑模变结构导引律

Adaptive Sliding Mode Variable Structure Guidance Law with Impact Angle Constraint

针对某些制导武器在精确命中目标的同时还要满足落角约束的要求,基于滑模变结构理论,提出一种带落角约束的自适应滑模变结构导引律。考虑末端弹目视线角速率变化剧烈和变结构抖振现象的问题,选取相对速度偏角作为滑模面,引入落角约束项;将目标机动视为有界干扰,利用Lyapunov理论进行了稳定性分析;采用变开关系数法和饱和函数法相结合的方法,大大削弱了变结构的抖振现象。最后,将该导引律应用于导弹实际模型中进行对比仿真,结果表明所提导引律针对固定目标和机动目标,相比传统方法,都能以更小的脱靶量和落角误差命中目标。

Aiming at the requirements of some guided weapons with attack accuracy and impact angle constraint, an adaptive sliding mode variable structure guidance law with impact angle constraint is pro- posed based on sliding mode variable structure control theory. Considering the rapid change of terminal line of missile-target sight angle sequence and the chattering phenomenon of variable structure, this guidance law chooses relative velocity deflection angle as the sliding mode, introduces the angular constraint, regards the target maneuvering as limited disturbance, and the stability of the guidance law is analyzed by using Lyapunov theory. Meanwhile, the chattering phenomenon is substantially weakened by the combination of variable switching term and saturation function. Finally, the simulation is made by applying the guidance law to the missile real model, and the results show that compared with traditional algorithm, the designed guidance law can hit the target with less miss distance and impact angle