基于自适应最优控制的有限时间微分对策制导律

针对固定末端时刻拦截机动目标的制导系统,本文首先构建了非线性有限时间微分对策框架,将导弹拦截非线性系统的最优问题转化为一般非线性系统的最优控制问题,并通过自适应动态规划算法(adaptive dynamic programming, ADP)获得近似最优值函数与最优控制策略.为了有效实现该算法,本文利用一个具有时变权值和激活函数的评价网络来逼近Hamilton-Jacobi-Isaacs(HJI)方程的解,并在线更新.通过李雅普诺夫法来证明本文提出的控制策略可保证闭环微分对策系统稳定性和评价网络权值近似误差的有界性.最后给出一个非线性导弹拦截目标系统的仿真例子验证了该方法的可行性和有效性.     

基于变速趋近律的离散滑模末制导律设计

针对离散化的末制导模型,基于一种新型离散变速趋近律设计了离散滑模制导律。利用该新型离散变速趋近律的特性消除了视线角速率的稳态振荡,使其渐进地趋于原点,并显著降低了系统抖振。将目标机动视为未知不确定性,采用干扰观测器方法对其进行在线估计和补偿,无需知道不确定性的界,只需知道其变化率有界,且无需满足匹配条件。仿真结果表明,所设计的基于新型离散变速趋近律的滑模制导律对目标机动具有鲁棒性,且无稳态振荡和系统抖振。     

拦截机动目标的范数型协同微分对策制导律

针对多个拦截弹协同拦截单个机动目标的情况,提出了一种范数型的协同微分对策制导律。在拦截弹和目标的控制系统均具有理想动力学特性且法向加速度均有界的条件下,对追逃对策问题进行分析,建立了线性化的多对一追逃对策运动模型,基于微分对策理论选取范数型的性能指标,推导得出了一种具有"bang-bang"结构的最优制导策略。上述制导律无需预先对目标的机动规律做假设,且可避免出现因加速度饱和而导致制导律失去最优性的现象。最后通过对拦截多种机动形式的目标进行仿真,验证了上述方法的有效性。     

飞行速度可调导弹三维制导律研究

为获得更好的制导性能,针对一类采用流量可调发动机的导弹,利用其所增加的飞行速度控制自由度,提出一种三维空间下比例导引+飞行速度控制的双重控制滑模制导律。以比例导引作为基础,在对二维、三维零控脱靶量分析的基础上,以零控脱靶量为跟踪目标选取合适的滑模面,并进一步使用辅助滑模面和有限时间超螺旋干扰观测器对滑模面中的不确定项进行估计,推导了减少脱靶量的速度控制制导律。仿真结果表明,相比于经典的比例导引,在考虑空气阻力的场景下,所设计的制导律脱靶量更小,弹道更平滑,滑模面收敛情况理想,实现了导弹飞行速度的主动控制。     

强化学习在导弹制导中的应用

阐述了强化学习的基本原理和特点,讨论了强化学习中评价函数的神经网络近似问题,重点分析了采用多神经网络近似评价函数的学习问题,实现了状态空间或任务的自动分解,提高了评价函数的推广能力,网络的学习是离线进行,并作为反馈控制器在线应用,并以A－学习为例,将强化学习应用于导弹的制导问题,仿真结果表明了强化学习在导弹制导或控制问题中的应用前景和有效性。     

不同制导信息带落角约束末制导律设计

对地制导武器在命中目标时,不仅希望得到最小的脱靶量,还希望命中目标时弹体姿态最佳,从而使战斗部能够充分发挥其作战效能,取得最佳毁伤效果,这就对导引任务的实现增加了终端角度约束。然而传统的导引方法并不能满足这一需求,所以带落角约束的制导律研究就显得尤为重要。本文根据反辐射制导武器导引头特点,在不同的制导信息下,引入了两种具有终端角度约束的导引律,并给出了详细的推导。最后通过仿真对这两种导引律的制导性能和适用条件进行了比较。仿真结果表明,以角度为制导信息的角度反馈型制导律具有计算量小,容易实现等优点,且在引入导引头测角误差后,对导引头的测角误差具有较大的鲁棒性。     

考虑导弹速度时变的角度约束最优中制导律

以导弹逆轨拦截高速运动目标为背景,本文运用间接高斯伪谱法设计带攻击角度约束的最优中制导律.通过零化弹目相对法向速度,将攻击角度约束转化为视线角约束.考虑导弹速度时变的情况,建立带角度约束的制导方程.根据极小值原理推导最优中制导律的解析表达式,运用高斯伪谱法对最优中制导律进行离散化,把微分方程转化为代数方程,避免了求解Riccati方程.该方法不需要预先知道导弹未来的速度信息,计算量小,具有较好的实时性.仿真结果表明该中制导律可以满足逆轨拦截对弹目交会角的约束,且中制导末端的过载较小.     

基于自适应动态规划的导弹制导律研究综述

自适应动态规划（Adaptive dynamic programming,ADP）作为最优控制领域的近似优化方法,是求解复杂非线性系统最优控制问题的有力工具.近年来,已成为控制理论与计算智能领域的研究热点.本文着重介绍ADP算法的理论研究进展及其在航空航天领域的应用.分析了几种典型的制导律优化设计方法,以及ADP方法在导弹制导律设计中的应用现状和前景.     

TV制导导弹的导引规律研究

TV制导导弹的导引一般可分为导航段、导引段和末制导段三个阶段。该文对不同阶段的导引规律进行了分析,针对导航段传统导引方法与算法的不足,提出了在导航段采用三星定位和惯导组合的制导法,以解决高动态环境下目标捕获、信号跟踪及导航精度的难题。针对TV导引头的瞬时视场较小,射手的反映速度有限,搜索速度不能太高,搜索区域不会很大的特点建立了导引段的先期导引与搜索规律模型。为了提高末制导段的导引精度,减小脱靶量,提出采用追踪法与比例法相结合的复合导引方法,实验仿真结果表明,导引精度得到了很大提高。     

水平面拦截对策问题的次最优制导律

本文运用微分对策理论研究了水平面上某战术导弹与目标飞机之间的最小时间变速拦截问题。在多重时间尺度分解的假定下,采用强迫奇异摄动方法(FSPT)求得了近似解析形式的次最优反馈制导控制规律。选用实际的空气动力数据进行了数值计算,结果表明该次最优制导律是有效的和便于实际应用的。     

Robust differential game guidance laws design for uncertain interceptor-target engagement via adaptive dynamic programming

In this paper, the problem of intercepting a maneuvering target is formulated as a two-player zero-sum differential game framework affected by matched uncertainties. By introducing an appropriate cost function that reflects the uncertainties, the robust control is transformed into a two-player zero-sum differential game control problem and therefore ensures the compensation of the matched uncertainties. Additionally, the corresponding Hamilton--Jacobi--Isaacs (HJI) equation is solved by constructing a critic neural network (NN). The closed-loop system and the critic NN weight estimation error are proved to be uniform ultimate boundedness (UUB) by utilising Lyapunov approach. Finally, the effectiveness of the proposed robust guidance law is demonstrated by using a nonlinear two-dimensional kinematics, assuming first-order dynamics for the interceptor and the target.     

一种带时间协同和角度约束的多导弹三维协同制导律

针对多枚导弹在三维空间从不同初始位置同时拦截机动目标的问题,设计了一种带视线角约束的有限时间协同制导律.首先,给出三维空间的导弹–目标相对运动方程并建立了考虑视线角约束的多弹协同制导模型.其次,对视线纵向及法向方向分别设计了相应的协同制导律.其中在视线方向基于多智能体有限时间一致性理论设计了协同制导律,保证各拦截弹能够同时击中目标;基于一种新型的固定时间非奇异终端滑模控制方法设计了视线法向上的角度约束制导律,使各拦截弹的视线角能够在固定时间内收敛至期望值,实现空间上的协同;同时,构造了扩张状态观测器估计目标加速度.最后,对三枚导弹同时拦截同一机动目标的情况进行仿真对比,验证了本文所提出协同制导律的有效性.     

Integrated Game Based Guidance with Nonlinear Autopilot Design for Maneuvering Target Interception

The integrated game theory based guidance law with nonlinear autopilot (GGNA) system is presented in this paper. The guidance law is designed based on linear differential game theory while considering the motion of the target in 3‐D space such that the distance between the missile and the target is minimized faster than before. The autopilot system based on quaternion representation is developed using sliding mode control method to generate the attitude command. The stability of the integrated guidance and nonlinear autopilot system is analyzed with Lyapunov stability theory. In addition, this research assumes wingless missiles in our context in order to reduce the nonlinear effect from the aerodynamics. Furthermore, in order to extend the operation range of missiles from endo‐atmosphere to exo‐atmosphere, the missiles are equipped with Thrust Vector Control (TVC) mechanisms and Divert Control System (DCS). Finally, extensive simulations incorporating aerodynamic models are demonstrated to verify the validity of the proposed integrated guidance/autopilot systems. Moreover, the simulation results reveal that the mission of intercepting a maneuvering target is successfully accomplished.     

Optimal guidance law for cooperative attack of multiple missiles based on optimal control theory

This article considers the problem of optimal guidance laws for cooperative attack of multiple missiles based on the optimal control theory. New guidance laws are presented such that multiple missiles attack a single target simultaneously. Simulation results show the effectiveness of the proposed algorithms.     

拦截高速机动目标的非线性自抗扰制导律

为实现导弹对目标的高精度拦截, 本文提出了基于加权齐次函数的非线性自抗扰拦截制导设计方法. 首先, 提出了基于加权齐次函数的非线性扩张状态观测器在线估计视线角速率和由目标加速度等内外不确定性因素构成的总扰动. 其次, 设计了基于非线性扩张状态观测器的非线性自抗扰三维制导律对总扰动进行补偿, 该制导律克服了高阶非线性项与强耦合项等不利因素的影响, 提高了拦截制导精度. 本文通过分析误差系统的动力学行为证明了闭环制导系统的稳定性和收敛性. 本文提出的方法在拦截精度等方面优于已有的基于线性扩张状态观测器和基于fal函数的扩张状态观测器的自抗扰制导方法. 仿真结果验证了本文所提出方法的有效性和优越性.     

滑模变结构有限时间收敛制导律

针对末端有入射角度约束的制导系统,基于滑模变结构控制思想设计了一种有限时间收敛的滑模制导律,使制导系统的视线角速率快速收敛到零,并令弹道倾角收敛到期望的入射角度.通过非线性控制系统的有限时间稳定性理论对该制导律进行了分析,给出了制导系统有限收敛时间的数学形式,证明了制导系统的有限时间收敛性.最后通过仿真进一步验证了该制导方法的有效性和鲁棒性.     

Capture region of a 3D PPN guidance law for intercepting high‐speed targets

The implementation of a classic three‐dimensional PPN guidance against a high‐speed nonmaneuvering target is analyzed. All the analysis is performed in a line‐of‐sight fixed coordinate. By utilizing an auxiliary function inspired from the tangential relative velocity at interception, a necessary and sufficient condition for the airfoil shape capture region for intercepting the target is obtained. In addition, to have a maximum range of the angle between a target velocity and line of sight, the optimal aiming of an interceptor is derived. Finally, a sufficient condition for the capture region with the finite line‐of‐sight turn rate constraint is also presented. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

A three-dimensional robust nonlinear terminal guidance law with ISS finite-time convergence

This paper presents a novel three-dimensional nonlinear terminal guidance law with finite-time convergence for intercepting manoeuvring targets. Different from the usual method of decoupling the missile-target relative motion into two-dimensional planes, this law is designed via using the coupled dynamics. The guidance law is derived based on the theory of finite-time input-to-state stability (ISS), which needs no assumption of the linearisation and the estimation of target accelerations. Under this law, the line-of-sight angular rates can be stabilised to a small domain of convergence around zero in finite time. The convergence rate and convergence domain can be adjusted by changing the guidance parameters. First, a sufficient condition on finite-time ISS of the guidance system is given, and is subsequently used to design the guidance law. Finally, simulation results are provided to show that the proposed guidance law possesses fast convergence rate and strong robustness to target manoeuvres.