攻击地面目标的飞行器需以一定的落角击中目标,且攻击过程中控制量应满足约束条件的限制。针对该问题提出了一种带落角约束与控制约束的纵向制导律。基于非线性的飞行器质心运动模型,通过坐标变换得到用于制导律设计的线性模型,将带落角约束与控制约束的制导问题转化为存在控制饱和的线性定常系统的镇定问题。利用参量李雅普诺夫方程方法对该线性定常系统设计低增益状态反馈律,通过推导得到带落角约束和控制约束的纵向制导律,并给出制导律参数的在线整定方法,保证视线角在给定时间内收敛至期望落角,且飞行过程中的控制量满足约束条件。仿真结果表明,提出的制导律能够适应多种飞行任务,且具有良好的工程适用性。
A certain impact angle and the observation of the control constraint are desired when a land-attack-missile attacks a stationary ground target. To address this problem,a longitudinal guidance law with constraints on the impact angle and the control was presented. Based on nonlinear center of mass motion equations of the missile,a linear model for guidance law design was derived by coordinate transformation. The guidance problem was converted to a stabilization problem of a linear time-invariance(LTI)system with control saturation. To stabilize the LTI system,a low gain state feedback law was designed utilizing the parametric Lyapunov equation approach. And a longitudinal guidance law with a design parameter was derived. A method tuning the design parameter of the guidance law was proposed. By tuning the parameter online,sight angle converged to the desired impact angle in finite time. And the control constraint was observed during flight. Simulation results show that the guidance law is adaptive to various missions and has a potential for engineering applications.