Aero-thermal heating constrained midcourse guidance using state-constrained model predictive static programming method

This paper proposes a multiple-constraints-guaranteed midcourse guidance law for the interception of the hypersonic targets. In traditional midcourse law design, the constraints of the aero-thermal heating are rarely taken into consideration. The performance of the infrared detection system may be degraded and the instability of the flight control system may be induced.To address this problem, a state-constrained model predictive static programming method is introduced such that both terminal constraints(position and angle) and optimal energy consumption can be ensured. As a result, a sub-optimal midcourse guidance,guaranteeing the aforementioned multiple-constraints to be never violated, is synthesized. Simulation results demonstrate the effectiveness of the proposed method.

INVESTIGATION OF TIGHTLY COUPLED SINS/GPS INTEGRATION MIDCOURSE GUIDANCE FOR AIR-TO-AIR MISSILES

The applied problems of SINS/GPS integration navigation system existing in midcourse guidance of air to air missiles have been investigated recently. In comparison with those investigations existing in current publications, a new tightly coupled SINS/GPS integration navigation system for air to air missiles, based on the decorrelated pseudo range approach, is presented in this paper. Because of high jamming and dynamic of air to air missiles, inertial velocity aiding GPS receiver is used to provide a more accurate, jam resistant measurement for midcourse guidance systems. A tracking error estimator is designed to distinguish the correlation that existed between pseudo range measurements and inertial information. It is found better to regard inertial velocity aiding errors as the noise of which statistical properties are unknown. So using mixed Kalman/minimax filtering theory, one can obtain the new tracking error estimator with simple and robust algorithm through constructing a composite filter consisting of two parts: Kalman filter for the noise of known statistics and minimax filter for the unknown. In order to ensure this simple estimator stability, a new method is proposed to choose its parameters, based on Khargonekars work. Moreover, it is demonstrated that the given method also ensures the proposed estimator optimality. All the work mentioned above is involved in the tightly coupled SINS/GPS integration midcourse system design in which a set of low accuracy inertial components is shared by SINS and autopilot. Simulation results of a certain type of air to air missile are presented. Due to decorrelation by the tracking error estimator, only small white noise of pseudo range measurements remains. So it is shown that application of the new midcourse guidance system results in better guidance accuracy, higher jam resistance.

Optimal midcourse trajectory cluster generation and trajectory modification for hypersonic interceptions

The hypersonic interception in near space is a great challenge because of the target’s unpredictable trajectory, which demands the interceptors of trajectory cluster coverage of the predicted area and optimal trajectory modification capability aiming at the consistently updating predicted impact point(PIP) in the midcourse phase. A novel midcourse optimal trajectory cluster generation and trajectory modification algorithm is proposed based on the neighboring optimal control theory. Firstly, the midcourse trajectory optimization problem is introduced; the necessary conditions for the optimal control and the transversality constraints are given.Secondly, with the description of the neighboring optimal trajectory existence theory(NOTET), the neighboring optimal control(NOC)algorithm is derived by taking the second order partial derivations with the necessary conditions and transversality conditions. The revised terminal constraints are reversely integrated to the initial time and the perturbations of the co-states are further expressed with the states deviations and terminal constraints modifications.Thirdly, the simulations of two different scenarios are carried out and the results prove the effectiveness and optimality of the proposed method.

Optimal midcourse trajectory planning considering the capture region

An optimal midcourse trajectory planning approach that considers the capture region（CR） of the terminal guidance is proposed in this article based on the Gauss pseudospectral method（GPM）. Firstly, the planar CR of the proportional navigation in terminal guidance is analyzed and innovatively introduced in the midcourse trajectory planning problems, with the collision triangle（CT） serving as the ideal terminal states parameters of the midcourse phase, and the CR area serving as the robustness against target maneuvers. Secondly, the midcourse trajectory planning problem that considers the path, terminal and control constraints is formulated and the well-developed GPM is used to generate the nominal trajectory that meets the CR demands. The interceptor will reshape the trajectory only when the former CR fails to cover the target, which has loosened the critical demand for frequent trajectory modification. Finally, the simulations of four different scenarios are carried out and the results prove the effectiveness and optimality of the proposed method.

A Novel Sliding-mode Guidance Law Based on Lie-group Method

Although the channel-decoupling assumption is often used in design of three-dimensional guidance laws, it loses its rationality for aircrafts with strong kinematics coupling because body rotation arises. To overcome this trouble, a novel guiding method was proposed based on Lie-group. After a model of 3D guidance is formulated using vectors, the precision guidance with ending angular constraints can be transformed into a problem involving the relation between directional angles and rotational angular velocities of certain vectors. When the guidance model is imposed a SO(3)-based description, a novel 3D sliding mode guidance law with ending angular constraints can be developed via Lie-group control method and variable structure control theory. Finally, the feasibility and performance of the guidance law were shown by simulating the examples.

基于序列凸规划的拦截弹中制导轨迹优化

针对强非线性多约束条件下拦截弹中制导轨迹优化问题,基于序列凸规划方法和捕获区域,提出一种针对固定时间约束下的轨迹优化算法。序列凸优化方法求解复杂多项式具有高效的计算效率,但在轨迹优化问题中应用序列凸规划有控制变量的强非线性和固定时间内终端约束难以收敛两大难点。首先,采用仿射变量将问题转化为仿射系统,并将仿射系统进行凸化与离散化,来解决非线性问题,然后,提出一种终端约束加权松弛化方法来解决固定时间内终端约束难以收敛问题,并将中制导问题转化为序列凸规划问题。仿真结果表明,所提算法能较快地生成符合多约束条件的拦截弹中制导轨迹。

基于零控脱靶量的大气层外拦截中制导方法研究

针对大气层外拦截器在中制导结束后还需要长时间无控飞行的情况,基于零控脱靶量思想采用最优控制理论,对拦截器和目标的相对运动关系进行了理论推导,以脱靶量和中制导加速度为性能指标,设计了一种拦截器发动机固定推进时间的中制导策略,研究了拦截器制导精度与零控脱靶量预测精度的关系,提出了调节拦截器机动过载大小的实现途径。仿真结果表明,设计的中制导律精度高、可靠性好、形式简单,在脱靶量计算得足够精确时,中制导结束后的零控脱靶量可控制在百米量级内,为拦截器以动能碰撞方式拦截目标创造了优良的末制导条件。

Discussion on neighborhood optimal trajectory online correction algorithm and its application range

This paper presents a neighborhood optimal trajectory online correction algorithm considering terminal time variation,and investigates its application range.Firstly,the motion model of midcourse guidance is established,and the online trajectory correction-regenerating strategy is introduced.Secondly,based on the neighborhood optimal control theory,a neighborhood optimal trajectory online correction algorithm considering the terminal time variation is proposed by adding the consideration of terminal time variation to the traditional neighborhood optimal trajectory correction method.Thirdly,the Monte Carlo simulation method is used to analyze the application range of the algorithm,which provides a basis for the division of application domain of the online correction algorithm and the online regeneration algorithm of midcourse guidance trajectory.Finally,the simulation results show that the algorithm has high real-time performance,and the online correction trajectory can meet the requirements of terminal constraint change.The application range of the algorithm is obtained through Monte Carlo simulation.

多用途导弹中末段交班研究

研究了中远程多用途导弹由中间段制导向末段制导过渡的交接班问题 .中间段采用的导引方法分为水平面和铅垂面两部分 ,以保证末段启控时导引头能捕获到目标 ;末段采用变有效导航系数逐步过渡的比例导引法 ,以实现两段弹道的衔接并获得良好的攻击性能 .仿真结果表明 ,末段启控时中、末段弹道过渡平滑 ,过载变化不超过弹体可用过载 ,可很好地完成中末段交班任务 .

拦截高速目标的中制导次优弹道修正

针对临近空间飞行器的快速发展所带来的拦截高速目标作战需求,应用模型静态预测规划(model predictive static programming,MPSP)方法设计了一种中制导次优弹道修正算法.首先,通过分析中末制导交接班时刻拦截弹的最佳交接状态,得到了零控拦截条件,该条件由拦截弹和目标的速度比以及二者的速度前置角唯一确定;其次,针对不满足零控拦截条件的情形,分析了在引入比例导引作为末制导律前提下的捕获区,得到了拦截弹和目标速度前置角组成的平面内的捕获区基本构成,建立了中末制导交接班时刻拦截弹需要满足的捕获区约束;然后利用高斯伪谱法(Gauss pseudospectral method,GPM)得到了满足零控拦截条件的基准弹道,应用MPSP设计了考虑捕获区约束条件限制的弹道修正算法;最后,仿真结果验证了所提方法的合理性以及有效性.

导弹中末制导弹道交接律研究

针对中远程导弹中末制导交班过程中的弹道交接问题,基于交接过渡段制导的思想设计了一种新的中末制导交接律。首先给出了满足导弹弹道一阶和二阶平滑的条件,然后分别采用三角函数和多项式函数形式的交接律平滑算子作为加权系数,求解出满足弹道平滑条件的平滑算子具体表达式。仿真结果表明:所设计的中末制导交接律算法简单,适用于导弹攻击过程中不同阶段制导律的弹道交接及实现中末制导交接过程中的弹道一阶和二阶平滑交接。

视线角约束自适应滑模中制导律

基于导弹和目标相对运动方程,设计了视线角约束自适应滑模中制导律。应用Lyapunov稳定性理论证明了该制导律能使制导系统在有限时间内收敛至滑动模态面;当制导系统进入滑动模态面后,基于积分理论证明了中末制导交班时刻视线角能够收敛至期望值且视线角速率可以收敛至零附近。进一步将该制导律扩展到三维空间的拦截问题。最后,针对拦截正弦机动目标进行了仿真。结果表明:设计的制导律鲁棒性强,引起的交班误差小。

基于二阶变分的中制导最优弹道修正

针对反临近空间高超声速目标拦截作战过程中的中制导弹道的规划与修正问题,设计了一种最优弹道修正算法。首先分析了在中制导阶段进行弹道规划与弹道修正的必要性,基于庞特里亚金最小值原理给出了基准最优弹道满足的一阶必要性条件,其次将一阶必要性条件进行二阶变分,得到控制量的修正量,利用基准弹道数据,通过逆向积分,将协态变量的偏差量表示为终端约束修正量以及状态变量偏差量的表达式,从而有效解决了协态变量偏差量的获取问题,最后进行了多种情形下的数字仿真,对所提算法进行验证并与高斯伪谱法(Gauss pseudospectral method,GPM)进行对比。结果表明,该方法不仅具有较高的求解精度,并且其求解效率远高于GPM,有利于弹上在线实现。

导弹协同制导中末交接班目标截获概率研究

为定量评估空空导弹协同制导的作战效果,对协同制导条件下中末交接班目标截获概率进行建模研究.根据协同制导的信息流程,给出修正指令计算方法,分析了影响协同制导的6种主要误差源及误差特性,并采用矢量法推导雷达测量误差、姿态测量误差、导航定位误差、传递对准误差和指令延时误差的传递模型,基于制导误差建立中末交接班的目标截获概率计算模型,得到截获概率与误差的定量关系,对目标截获概率和误差灵敏度进行了仿真分析.结果表明,目标截获概率对指令延时误差和制导载机雷达测量误差的敏感性最高.

防空导弹武器中末制导交班灵敏度分析

复杂战场环境下,中远程防空导弹武器的中末制导交班问题越来越突出。实战要素影响到武器系统的各个环节,尤其是传感器测量精度,从而影响中末制导交班概率。通过灵敏度分析方法,对实战条件下影响中末制导交班的关键因素进行了分析,筛选出了高敏感影响因素,并得到了表征其影响程度的定量化灵敏度系数。

主动寻的末制导的截获性能分析

研究了雷达指令修正惯导中制导加主动寻的末制导的复合制导体制下，雷达定位误差造成的导引头天线指向角误差和多普勒定频误差的统计特性，计算了末制导的截获概率，明确了不同因素对截获性能的影响。

基于邻域最优控制的跟踪制导律设计

针对拦截临近空间高超声速飞行器的中制导过程,设计了一种基于邻域最优控制(NOC)的跟踪制导律.首先,采用高斯伪谱法离线设计得到满足终端约束与过程约束的标称最优弹道;其次,为了对标称弹道进行精确跟踪,将弹道满足的一阶最优性必要条件进行二阶变分,在标称弹道邻域内得到一条满足二阶最优的修正弹道;最后,应用间接高斯伪谱法,在离散的勒让德-高斯(LG)点上将转化后的两点边值问题离散为代数方程进行矩阵求逆运算,利用标称弹道数据求得反馈控制律.仿真结果表明,该方法能有效地消除跟踪误差,并且能够满足在线实施的要求.

一种弹目遭遇点预测方法

为充分利用舰空导弹中制导段所获信息并减小导弹中制导段的弹道曲率，给出一种弹目预测遭遇点的解算方法，并据此设计比例导引制导律。在初始发射坐标系中，假设目标由当前位置以当前速度大小沿当前速度方向匀速运动至遭遇点，导弹由当前位置以当前速度大小按照一定的导引规律匀速运动至遭遇点。在该假设条件下，导弹到达遭遇点的总航路大小一方面按照导引弹道计算，另一方面按照当前时刻导弹与遭遇点的直线距离近似计算，由此可解算出导弹（或目标）运动至遭遇点的剩余飞行时间，从而得到预测遭遇点的位置信息。仿真结果验证了该方法的有效性。

导弹中制导末段的最优搜索

研究超视距导弹中制导末段利用导弹的剩余动力 ,自动搜索活动目标 ,使目标捕捉概率达到最大的最优搜索问题 .给出了活动目标的位置概率分布 ;提出了基于活动目标位置概率分布的导弹搜索航线的规划方法 ;拟订了搜索系统的组成方案并对系统进行了设计 ;对该系统进行了仿真 ,验证它的活动目标的捕捉概率 .

空地导弹对应不同驾驶仪下的中制导高度控制回路设计

使用频率法和根轨迹法设计了姿态驾驶仪内回路对应的高度控制回路;对内回路姿态驾驶仪结构和过载驾驶仪结构分别对应的高度控制回路进行了对比分析。结果表明,两种内回路驾驶仪结构对应的高度控制回路性能基本一样,都是可行的。并在此基础上分析了内回路驾驶仪结构切换对中末制导交班切换的影响。结果表明,驾驶仪结构切换对中末制导交班切换的影响很小,可以考虑将中末制导交班切换时的两个切换同时进行。