带攻击角约束的有限时间收敛滑模制导律

Finite-Time Convergent Sliding Mode Guidance Law with Impact Angle Constraint

针对导弹带攻击角度约束打击目标问题,提出带攻击角约束的有限时间收敛滑模制导律。首先,建立弹目相对运动关系,基于滑模变结构理论,采用一种快速非线性终端滑模面,选取自适应幂次趋近律,进行制导律设计。其次,利用Lyapunov理论进行制导律的稳定性分析,并对制导律有限时间收敛进行分析,采用饱和函数代替符号函数,减小抖动的影响。最后,将所设计的制导律与带落角约束的偏置比例导引律进行对比。仿真表明,所设计的制导律性能更加优越,具有较强的鲁棒性,达到期望攻击角度的要求。

For the issue of missile attacking the target with impact angle constraint, a finite-time convergent sliding-mode guidance law with impact angle of the constraint is put forward. First of all, the missile-target relative motion relationship is established, and the guidance law is designed based on the sliding mode variable structure theory by using a fast nonlinear terminal sliding mode surface and selecting adaptive exponential reaching law. Then, the stability of the guidance law is analyzed by using Lyapunov theory, and analysis is also made to the finite-time convergence. Saturation function is used instead of symbolic function to reduce the influence of jitter. Finally, the designed guidance law is compared with the offset proportional guidance law with fall angle constraint. Simulation shows that the designed guidance law has better performance, stronger robustness, and can achieve the requirement of the expected impact angle.