Ideal proportional navigation for exoatmospheric interception

Ideal proportional navigation (IPN) is a natural choice for exoatmospheric interception for its mighty capture capability and ease of implementation. The closed-form solution of two- dimensional ideal proportional navigation was conducted in previous public literature, whereas the practical interception happens in the three-dimensional space. A novel set of relative dynamic equations is adopted in this paper, which is with the advantage of decoupling relative motion in the instantaneous rotation plane of the line of sight from the rotation of this plane. The dimension-reduced IPN is constructed in this instantaneous plane, which functions as a three-dimensional guidance law. The trajectory features of dimension-reduced IPN are explored, and the capture regions of dimension-reduced IPN with limited acceleration against nonmaneuvering and maneuvering targets are analyzed by using phase plane method. It is proved that the capture capability of IPN is much stronger than true proportional navigation (TPN), no matter the target maneuvers or not. Finally, simulation results indicate that IPN is more effective than TPN in exoatmospheric interception scenarios.     

基于时间最优的大气层外拦截律设计

针对大气层外拦截提出了一种基于拦截时间最短的拦截律。根据最优控制理论由相对运动参数确定拦截弹时间最优的推进方向,用变结构控制理论调整拦截弹姿态角以跟踪指令姿态角,拦截弹沿体轴方向持续推进直至拦截结束。拦截律要求控制器在较短的时间完成对指令姿态角的跟踪后即停止工作。仿真结果表明：拦截律有很好的拦截精度,可引导拦截弹对目标实施碰撞杀伤。     

Optimal terminal guidance for exoatmospheric interception

In this study, two optimal terminal guidance (OTG) laws, one of which takes into account the final velocity vector constraint, are developed for exoatmospheric interception using optimal control theory. In exoatmospheric interception, because the proposed guidance laws give full consideration to the effect of gravity, they consume much less fuel than the traditional guidance laws while requiring a light computational load. In the development of the guidance laws, a unified optimal guidance problem is put forward, where the final velocity vector constraint can be consid-ered or neglected by properly adjusting a parameter in the cost function. To make this problem ana-lytically solvable, a linear model is used to approximate the gravity difference, the difference of the gravitational accelerations of the target and interceptor. Additionally, an example is provided to show that some achievements of this study can be used to significantly improve the fuel efficiency of the pulsed guidance employed by the interceptor whose divert thrust level is fixed.     

大气层外拦截器最优中制导律设计

中制导是大气层外拦截嚣复合制导体系的关键技术之一,对消除主动段结束时的速度误差和构造有利的末制导初始条件有着重要意义.以机动能力需求最小为优化目标,本文提出了一种针对大气层外拦截器的中制导规律.能量最优中制导规律的关键是在预测拦截点附近寻找最优的拦截点和对应的最优需用速度,并满足中段机动能力约束.仿真试验结果表明,该方...     

大气层外拦截器脉冲制导律

针对大气层外拦截器（EKV）轨控发动机垂直于体轴且导引头视场角极窄的特点,提出了一种采用固定推力发动机沿视线法向方向调整拦截弹速度矢量实施轨控的脉冲制导（PG）方法。制导开始时制导系统确定制导脉冲的施加时刻及制导脉宽,并引导制导系统选择轨控发动机执行;用施加修正制导脉冲的方式修正拦截双方地球引力加速度差对拦截效果的影响,并确定修正脉冲的施加时刻;选择修正制导脉冲施加时刻通过实施的脉冲修正方案消除末制导段的零控脱靶量。仿真结果表明：与修正的真比例导引制导相比,脉冲制导的能耗少、实施易,拦截过程中拦截双方的高度差越小,其拦截代价也越小。     

基于有限元法的大气层外弹道式目标表面温度场分析

获取目标表面温度场是进行红外特征分析的重要前提。为确定大气层外弹道式目标的表面温度场分布,建立了有限元模型。根据目标温度场的轴对称分布特点,在柱坐标系内建立了二维瞬态热传递模型,从而降低了计算量。与当前大部分的有限元软件和文献不同,严格分析了温度非均匀性有限单元的辐射热损失,并推导出轴对称三结点三角形单元的辐射热损失公式。为了能够使用Galerkin法求解时间微分方程组,将辐射热损失视为与时间相关的热载荷项,并用Newton\|Raphson法迭代求解处理后得到的非线性方程组。一个简单的数值实验表明了所提出方法的有效性,最后应用该法求解了目标飞行全程的表面温度场分布。