考虑驾驶仪动态特性的固定时间收敛制导律

Fixed-time convergent guidance law considering autopilot dynamics

针对打击机动目标的制导问题,设计了一种同时考虑攻击角度约束、自动驾驶仪动态特性和固定时间收敛的新型制导律。首先,基于非奇异终端滑模控制和固定时间稳定性理论,采用反步递推方法设计制导律。在制导律设计过程中,设计了一种固定时间收敛的非奇异终端滑模面,基于固定时间控制和滑模控制,设计虚拟控制律,构造一种非线性一阶滤波器解决传统反步设计中的“微分膨胀”问题。基于超螺旋算法和固定时间稳定性理论,设计了一种固定时间收敛的滑模干扰观测器,用于估计目标机动等干扰。然后,基于Lyapunov稳定性理论,对制导律的固定时间稳定性进行了证明,并给出了收敛时间的表达式。最后,通过仿真分析,验证了所提制导律的有效性,和现有制导律相比,所提制导律具有较高的制导精度和角度约束精度、较快的系统收敛速度以及较少的能量消耗。

A new guidance law considering the impact angle constraint,autopilot dynamic characteristics,and fixed-time convergence is designed for the guidance problem of attacking maneuvering targets.First,based on nonsingular terminal sliding mode control and fixed-time stability theory,the backstepping method is used to design the guidance law.In the process of the design,a nonsingular terminal sliding mode surface with fixed-time convergence is designed.Based on fixedtime control and sliding mode control,the virtual control law is designed and a nonlinear first-order filter is constructed to solve the problem of“differential expansion”in the traditional backstepping design.Based on the super-twisting algorithm and fixed-time stability theory,a fixed-time convergence sliding mode disturbance observer is designed to estimate the target maneuvering and other interferences.Then,based on the Lyapunov stability theory,the fixed-time stability of the guidance law is proved,and the expression for convergence time is given.Finally,the effectiveness of the proposed guidance law is verified by simulation analysis.Compared with the existing guidance laws,the proposed guidance law has higher guidance precision and angle constraint accuracy,faster system convergence speed,and less energy consumption.