【作者】 孙未蒙；

【导师】 郑志强；

【作者基本信息】 国防科学技术大学 ， 控制科学与工程， 2008， 博士

【摘要】 空地制导武器多任务、复合型、通用化、精确化的发展趋势,要求在满足攻角、速度、弹体姿态等多方面的约束条件下,实施制导武器的精确打击。针对多约束条件下制导律设计中存在的参数优化、鲁棒性、目标运动、模型失配、运动耦合等方面的关键性问题,论文循序渐进、逐步深入地展开对制导律的研究和设计工作,主要工作及创新点如下：1、为了便于制导律性能的验证,论文首先建立了空地制导武器的空间弹道方程以及数字仿真验证平台,并利用仿真结果指出了传统制导律所存在的局限性,为多约束条件下制导律的设计提供了依据和基础。2、多约束条件下制导律的设计首要考虑的是参数优化问题,论文利用最优控制理论完成了多约束条件下的最优制导律设计。设计中,在将空地制导武器三维空间分解成俯冲平面和转弯平面的基础上,把弹体动态特性引入导引回路中,将末端姿态角约束转化为最优控制的终端约束问题,利用微分矩阵Riccati方程,设计了一种多约束条件下的最优制导律。并利用梯度下降法和模糊控制理论,设计了一种传统速度约束控制的改进算法。最优制导律的设计为论文其他制导律参数的整定提供了依据。3、为了增强制导律的鲁棒性,克服制导武器飞行时参数摄动和外界扰动的影响,论文利用变结构控制理论,设计了一种多约束条件下的最优滑模制导律。其方法是在双平面分解假设的基础上,利用变结构控制理论中的最优滑模控制器设计方法,推导出一种三维空间内多约束条件下的最优滑模制导律。滑模制导律的鲁棒性为后续制导律的设计提供了借鉴。4、为了将针对固定目标的最优制导律推广到对运动目标的制导中去,论文利用虚位移概念构建立了弹目相对运动关系,根据Lyapunov函数和变结构控制理论,设计了一种目标运动时多约束条件下的变结构制导律,并利用最优制导律整定了制导参数。同时利用滑模理论建立了一种非线性观测器,对目标参数等未知量进行估计和预测。5、针对制导模型失配有可能导致脱靶的问题,通过对模型参考自适应控制律算法的研究,设计了一种多约束条件下的模型参考自适应制导律。论文从研究一类典型的非线性时变系统着手,以模型参考控制和变结构控制理论为基础,设计了两个模型参考自适应控制律算法。然后以线性模型作为制导参考模型,最优制导律作为参考模型控制输入,根据模型匹配条件,利用模型参考自适应控制律算法,得到一种多约束条件下的模型参考自适应制导律。6、利用双平面分解假设条件设计制导律时,忽略了弹体滚动带来的运动耦合问题,为了克服这种设计缺陷,论文利用李群控制理论和滑模控制理论,推导出一种多约束条件下基于李群方法的滑模制导律。在将制导律分解成倾斜转弯和侧滑转弯制导指令形式的基础上,分析了制导指令分解所带来的制导信息损失的特点。本文围绕多约束条件下制导律设计的相关理论和关键技术,运用最优控制、变结构控制、李群控制等现代控制理论,采用理论推导和数值仿真相结合的研究方法,开展了多约束条件下制导律设计问题的研究。本文的研究成果是对多约束条件下高精度制导律设计的有益探索,具有重要的理论价值和良好的应用前景。更多还原

【Abstract】 With the tide of the multi-roles, complexity, currency and precision in the air-to-surface guided weapons, we need to improve the precision of the guidance law for impact with angular constraints. In order to design the guidance law with terminal impact angle constraints, we study on the key techonology of optimal, robust, target moving, model-mismatching and kinematic coupling in guidance law step by step. The main work and contributions can be exhibited as follows:1.The trajectory model of air-to-surface guided weapon and the simulation system are presented for the convenience of the tests of guidance laws in the dissertation. Accordingly, the deficiencies of the tradition guidance law were analyzed from the simulation results.2.The design of the optimal guidance law with terminal impact angle constraints is accomplished in the dissertation, because the parameter optimization is the core problem. After the 3-dimensional (3D) terminal movement of aerial vehicles is divided into the movements of pitching plane and swerve plane, the guidance law is designed independently. Considering the terminal impact constraints of miss-distance, angle of trajectory inclination, angle of trajectory rotation and system dynamics, the 3D optimal guidance law is computed by the differential matrix Riccati equation of optimal control. And the traditional algorithm of max-velocity control is also improved by the adaptive gradient methods and Takagi-Sugeno fuzzy theory. The parameters of late guidance laws can refer optimization parameters to tuning.3.Aiming at enhancing the robust of guidance law, an optimal sliding mode guidance law with terminal impact angle constraints is proposed to depress the influence of parameter perturbation and outside disturbance during flight. The optimal sliding mode controller and the optimal guidance law are used to design the guidance law based on the channels decoupling in 3D guidance model. The robust of guidance law is tested through the simulation. So the robust of other guiandance laws can refer the study of the optimal sliding mode guidance law.4.When the target moves, it is difficulty to generalize the optimal guidance law directly. To solve the problem of undershoot, the engagement geometry between missile and target is established using virtual displacement. Based on the sliding-mode variable structure control theory and Lyapumov function, a new 3D variable structure guidance law for maneuvering target is deduced, which is satisfied with the multi-constraint conditions of precision, impact angular and incidence angular. In order to estimate and predict the unmeasured parameters, a nonlinear sliding-model observer is designed.5.A model-reference adaptive variable structure guidance law is deduced from the model reference adaptive variable structure control law, while mismatching of guidance model is resulted from the time-varying and system uncertainty in flight. After a kind of typical nonlinear time-varing system is analyzed, two kinds of model reference adaptive variable structure control law are designed based on the model reference adaptive control theory and the variable structure control theory. Then the linear guidance model and the optimal guidance law are taken as the nominal system and reference guidance law, respectively. Through model matching condition and integral sliding mode, a model-reference adaptive variable structure guidance law with terminal impact angle constraints is proposed by model reference adaptive variable structure control law.6. There are some disadvantages during the guidance law design using the channels decoupling assumption, because the rotation of aircraft body can result in strong kinematics coupling. Once a model of 3D guidance is formulated using vectors, the 3D sliding mode guidance law based on Lie group can be developed from the Lie group control theory and sliding mode contol theory. And then the guidance command of BTT (Bank-to-turn) control and STT (Skid-to-turn) control is shown. Based on the loss of guidance information, a new viewpoint on decoupling of guidance command is proposed.In summary, the dissertation concentrates on the basic theoretical and key technologies of the guidance law with the flight velocity and impact angle constraints. During the studying of guidance law design, the optimal control theory, variable structure control theory, Lie group control theory etc are introduced and utilized. A series of 3D guidance law with terminal impact angle constraints are achieved and tested by theory deduction and simulation. These research results are meaningful for the application of the new concept and principles of the guidance law with terminal impact angle constraints in precision strike.更多还原