基于LQR/SMVS的鲁棒最优制导律研究

针对导弹在拦截机动目标的特点,以最优控制中的线性二次调节(LQR)和滑模变结构(SMVS)为理论基础,推导出一鲁棒最优制导律。它综合了LQR和SMVS的优点,不仅脱靶量和消耗能量小,而且对目标机动等干扰不敏感,具有鲁棒性。仿真结果表明,所得制导律具有良好的性能,具有一定的应用价值。     

一种新的变结构制导律研究

在非线性相对运动学基础上提出了一种新的变结构制导律。变结构制导律仅利用了目标加速度界限的信息,因而在拦截过程中,并不需要精确的测量目标加速度,也就是取得了对目标机动的鲁棒性。在执行上,变结构制导律仅使用了视线转率测量值,因而和比例导引同样简单。仿真结果表明,所提出的制导律与比例导引相比有较大的性能改善。     

Methods and advances in the study of aeroelasticity with uncertainties

Uncertainties denote the operators which describe data error, numerical error and model error in the mathematical methods. The study of aeroelasticity with uncertainty embedded in the subsystems, such as the uncertainty in the modeling of structures and aerodynamics, has been a hot topic in the last decades. In this paper, advances of the analysis and design in aeroelasticity with uncertainty are summarized in detail. According to the non-probabilistic or probabilistic uncer- tainty, the developments of theories, methods and experiments with application to both robust and probabilistic aeroelasticity analysis are presented, respectively. In addition, the advances in aeroelastic design considering either probabilistic or non-probabilistic uncertainties are introduced along with aeroelastic analysis. This review focuses on the robust aeroelasticity study based on the structured singular value method, namely the ~t method. It covers the numerical calculation algo- rithm of the structured singular value, uncertainty model construction, robust aeroelastic stability analysis algorithms, uncertainty level verification, and robust flutter boundary prediction in the flight test, etc. The key results and conclusions are explored. Finally, several promising problems on aeroelasticity with uncertainty are proposed for future investigation.     

基于扰动观测器的指数时变滑模再入姿态控制

针对再入飞行器姿态控制问题,设计了一种全局鲁棒的基于扰动观测器的指数时变滑模姿态控制器,使得在存在匹配模型参数不确定性和外部扰动情况下仍能够实现精确的姿态控制。首先对飞行器模型进行反馈线性化解耦,将俯仰、滚转、偏航通道分解为3个独立的二阶系统。然后以俯仰通道为例,设计指数时变滑模控制器,使得系统具有全局鲁棒性。进一步,为了减小采用饱和函数消除滑模控制抖振而带来的系统跟踪误差,引入扰动观测器,设计了一种基于扰动观测器的指数时变滑模控制系统。最后,以某飞行器为例建立六自由度仿真模型,在考虑大气密度、转动惯量偏差以及外部高频扰动的情况下,验证了加入扰动观测器后对系统性能的提高。     

基于ESO的用户星天线跟踪指向控制技术

基于独特的非线性扩张状态观测器(ESO),提出了一种用户卫星天线跟踪指向控制系统。该系统由程序跟踪内环和自动跟踪外环组成。内环控制器由三阶ESO、线性比例微分控制律和静态解耦律组成。外环控制器为一简单的积分控制器。ESO能够在不依赖天线模型的情况下估计出系统状态和总扰动(称为扩张状态)。利用该扩张状态实现动态反馈补偿,则天线系统被简化为解耦的积分系统。基于ESO设计天线控制系统,无需精确的用户卫星天线模型。仿真结果表明,提出的天线控制系统具有较高的跟踪指向性能和对干扰和不确定性具有较强的鲁棒性。     

模型参考自适应系统的稳健性

 本文证明飞机俯仰角速度的模型参考自适应控制系统(MRACS)对未建模的长周期模态的稳健性。将飞机纵向运动的传递函数经因式分解后,得出一种特定的状态方程,通过变换,可把长周期模态的影响变成只考虑短周期模态的近似系统的等效慢变化干扰作用。由于MRACS具有自动调节控制增益以克服被控对象参数慢变及抑制慢变干扰的能力,从而整个闭环系统的稳健性得到了保证。     

多层验前信息下多维动态参数的Bayes试验分析

文中讨论了多维动态参数具有多层验前信息时的建模问题。在一定条件下,给出了验前分布的表示。对于动态参数的Bayes估计,进行了精度分析和风险分析。     

A novel strong tracking cubature Kalman filter and its application in maneuvering target tracking

The fading factor exerts a significant role in the strong tracking idea. However, traditional fading factor introduction method hinders the accuracy and robustness advantages of current strong-tracking-based nonlinear filtering algorithms such as Cubature Kalman Filter (CKF) since traditional fading factor introduction method only considers the first-order Taylor expansion. To this end, a new fading factor idea is suggested and introduced into the strong tracking CKF method. The new fading factor introduction method expanded the number of fading factors from one to two with reselected introduction positions. The relationship between the two fading factors as well as the general calculation method can be derived based on Taylor expansion. Obvious superiority of the newly suggested fading factor introduction method is demonstrated according to different nonlinearity of the measurement function. Equivalent calculation method can also be established while applied to CKF. Theoretical analysis shows that the strong tracking CKF can extract the third-order term information from the residual and thus realize second-order accuracy. After optimizing the strong tracking algorithm process, a Fast Strong Tracking CKF (FSTCKF) is finally established. Two simulation examples show that the novel FSTCKF improves the robustness of traditional CKF while minimizing the algorithm time complexity under various conditions.     

Adaptive controller design for satellite attached by non-cooperative object

When non-cooperative body attachment occurs in space, the inertia of the new combination and the change of the system’s momentum are unknown. This uncertainty may lead to the instability of the spacecraft’s attitude control. In order to solve this problem, we propose an adaptive control scheme based on the inertia estimation of the new, combined system of non-cooperative body and satellite. This method can allow the new combination of different situations to reach a stable state with a high level of precision and speed. In this paper, the stability of the adaptive control scheme is proven by constructing a Lyapunov function. A simulation environment in which a non-cooperative body attaches to a satellite attaches to is constructed. The simulation shows that the attitude error converges to a small field when using the control scheme, regardless of unfavorable cases, including unknown inertia parameters, added momentum. In addition, the simulation results show the strong robustness of the control scheme for the new combination.