H∞ output tracking control for flight control systems with time-varying delay

For flight control systems with time-varying delay, an H∞ output tracking controller is proposed. The controller is designed for the discrete-time state-space model of general aircraft to reduce the effects of uncertainties of the mathematical model, external disturbances, and bounded time-varying delay. It is assumed that the feedback-control loop is closed by the communication network, and the network-based control architecture induces time-delays in the feedback information. Suppose that the time delay has both an upper bound and a lower bound. By using the Lyapu- nov-Krasovskii function and the linear matrix inequality （LMI）, the delay-dependent stability criterion is derived for the time-delay system. Based on the criterion, a state-feedback H∞ output tracking controller for systems with norm-bounded uncertainties and time-varying delay is presented. The control scheme is applied to the high incidence research model （HIRM）, which shows the effectiveness of the proposed approach.     

运动图象的数字压缩技术及其在军事装备中的应用

运动图象具有信息量大、动态感强、真实直观等特点,然而在实际应用中却存在数据量大,处理时间要求高等问题,所以研制压缩比大,实现方法灵活的数字图象压缩算法成为了近几年来信息处理的一个非常活跃的研究热点。本文主要介绍了运动图象的数字压缩的原理和方法,对高效压缩算法MPEG-4中所用到的关键技术进行了详细的讨论,最后结合工程实践简述了数字图象压缩技术在我军装备中的应用情况。     

溶胶-凝胶法制备复合材料用氧化铝基体及涂层研究

采用溶胶—凝胶法,分别研究了用三种起始物异丙醇铝［Ａｌ（ＯＣ３Ｈ７ｉ）３］、氯化铝（ＡｌＣｌ３·６Ｈ２Ｏ）、硝酸铝［Ａｌ（ＮＯ３）３·９Ｈ２Ｏ）］,制备碳纤维三维编织物增强复合材料用氧化铝基体及涂层的工艺,考察了三种体系反应物配比、水解温度、反应时间等因素对制得的三种溶胶体系性能的影响,获得了较佳的溶胶配制参数;还考察了三种溶胶体系在通常情况下和在编织物中的凝胶化情况,获得了较佳的凝胶化条件;同时还研究了不同条件下三种凝胶的裂解产物及其晶体类型。结果表明,不管经过何种途径,凝胶在经１２６０℃裂解后均可获得α－Ａｌ２Ｏ３。     

航空发动机控制系统性能恢复设计:H_∞/PR

对于航空发动机这样一类状态及输出矩阵存在摄动的系统,提出了一种直接根据性能指标作为恢复的目标的性能恢复理论设计方法。首先进行具有稳定及性能鲁棒性的状态反馈的H∞控制设计,然后通过设计一个状态观测器使得上述状态反馈控制的特性得以恢复。     

应用于MEMS_SINS/GPS组合导航系统的H_∞容错滤波算法

针对基于微机电系统(MEMS,micro electro mechanical system)的捷联惯性导航系统(SINS,strapdown inertial navigation system)与全球定位系统(GPS,global positioning system)组成的组合导航系统中存在不确定干扰并且GPS量测输出中经常含有故障信号的情况,提出一种H∞容错滤波算法,能够对不确定噪声干扰具有鲁棒性,并且能够在检测到故障信号后进行容错计算,使滤波精度始终保持在要求的范围内.基于H∞滤波器,在状态估计方程中加入加权因子,使滤波器具有容错的功能,并且适用于组合导航中量测分量的数量级相差很大的情况.仿真试验结果表明,该算法能有效降低GPS中故障信号的不利影响,使系统在故障存在期间仍能正常工作.     

视觉导航下基于H2/H∞的航迹跟踪

为了从理论上研究视觉导航系统的特性,首先在物理上将视觉导航系统划分为传感器(摄像头、激光测距仪)和视觉处理计算机。针对视觉处理计算机,建立视觉位置测量模型。将视觉位置测量模型的不确定性分为参数不确定性和输入干扰2种。然后通过仿真详细分析了视觉位置估计针对不同模型不确定性的敏感程度。最后在引入视觉位置测量模型不确定性的基础上研究H₂/H_∞混合鲁棒控制在航迹跟踪上的应用,并给出了保证航迹控制系统稳定性和跟踪性能情况下的视觉位置测量模型摄动范围,对计算机视觉算法的研究具有一定的指导意义。     

PCS7-400H冗余控制在KM6水平舱中的应用

为满足载人航天人-舱-服出舱活动试验任务的需要,提高系统的可靠性,KM6载人航天器空间环境模拟设备的水平舱测控系统采用SIMATIC PCS7冗余集散控制系统的方式,对所有关键环节包括控制计算机、CPU、电源、网络、I/O模块等都进行了冗余备份。文章较详细地介绍了PCS7-400H冗余功能在测控系统中的实现及测量原理,并在KM6水平舱中的实际运用中,大大地增加了系统运行的可靠性和稳定性。     

Gain self-scheduled H_∞ control for morphing aircraft in the wing transition process based on an LPV model

This article investigates gain self-scheduled H 1 robust control system design for a tailless fold- ing-wing morphing aircraft in the wing shape varying process. During the wing morphing phase, the aircraft’s dynamic response will be governed by time-varying aerodynamic forces and moments. Nonlinear dynamic equations of the morphing aircraft are linearized by using Jacobian linearization approach, and a linear parameter varying (LPV) model of the morphing aircraft in wing folding is obtained. A multi-loop controller for the morphing aircraft is formulated to guarantee stability for the wing shape transition process. The proposed controller uses a set of inner-loop gains to provide stability using classical techniques, whereas a gain self-scheduled H 1 outer-loop controller is devised to guarantee a specific level of robust stability and performance for the time-varying dynamics. The closed-loop simulations show that speed and altitude vary slightly during the whole wing folding process, and they converge rapidly after the process ends. This proves that the gain self-scheduled H 1 robust controller can guarantee a satisfactory dynamic performance for the morphing aircraft during the whole wing shape transition process. Finally, the flight control system’s robustness for the wing folding process is verified according to uncertainties of the aerodynamic parameters in the nonlinear model.     

H1 output tracking control for flight control systems with time-varying delay

For flight control systems with time-varying delay, an H1 output tracking controller is proposed. The controller is designed for the discrete-time state-space model of general aircraft to reduce the ef...     

一类模糊时滞系统的鲁棒二次稳定和H∞控制

研究了一类连续不确定模糊时滞系统的鲁棒二次稳定问题。首先给出不确定时滞系统的自治系统稳定的充分条件,在此基础上设计状态反馈控制器,给出全局二次可稳定的充分条件。相比已有的理论成果,更进一步考虑了系统的日。性能指标,使系统在满足二次可稳定的同时也满足H∞性能指标,并将所得的条件转化为线性矩阵不等式以便借助Matlab完成求解。最后的算例验证了方法的可行性。