基于滑模反步法的HSV被动容错控制设计

针对高超声速飞行器(HSV)无动力再入过程中舵面发生损伤故障的情况,设计了一种基于滑模反步法的姿态被动容错控制器。以公开的Winged-Cone飞行器非线性动态模型及其气动力与力矩为基础,对非线性模型进行时标分离处理,将姿态控制系统分解为姿态角速率与姿态角的快慢双回路系统。并以反步法为基础,结合滑模控制与动态面技术设计了被动容错控制器。通过Lyapunov稳定性分析以及数值仿真可知,所设计的被动容错控制器可以在没有任何损伤故障信息的情况下,保障姿态控制系统的稳定性与鲁棒性。     

飞行控制计算机余度管理策略研究

为满足系统可靠性指标的要求,采用了余度技术,研制了双通道余度飞行控制计算机.在该研究对象的基础上,进行了一种硬件冗余和软件管理的余度管理策略的研究和设计,提出了多余度信号监控表决算法、基于CAN总线的故障检测机制和系统重构与恢复的方法.故障注入实验表明,样例余度飞行控制计算机在遇到故障时能够实时检测出故障,诊断故障类型,并对故障进行处理,完成系统重构,提高了飞行控制系统的任务可靠性,保证无人机的飞行安全.     

基于滑模与控制分配的六旋翼飞行器容错控制

针对六旋翼飞行器的执行机构失效故障, 提出一种基于滑模和控制分配方法的容错控制方案; 采用了分层设计结构, 将基本控制律设计与控制分配律分为两个独立的部分, 针对系统建模不确定性与外界干扰, 设计滑模控制律, 提高了系统的鲁棒性, 运用控制分配方法, 在飞行器发生失效故障甚至卡死故障时, 在线调解控制分配矩阵, 减小故障机构对整体飞行性能的影响。仿真结果验证了所提容错控制的正确性和有效性。     

关于近空间飞行器飞行控制系统研究设计的几个问题

讨论了近空间飞行器飞行控制系统研究设计的几个问题。首先指出了研究近空间飞行器的国内外形势和近空间飞行器研究的重要性;接着就近空间飞行器飞行控制的几个重要问题:飞行运动控制的建模问题,飞行姿态控制的鲁棒性问题,飞行姿态与重心运动的一体化协调控制问题,飞行与发动机的一体化协调控制问题,飞行控制的抗干扰问题提出了相应的方法和看法;最后就近空间飞行器飞行控制系统的设计原则提出了自己的体会和看法,指出了用一体化协调控制的思想进行近空间飞行器飞行控制系统分析设计的重要性。     

基于5G网络的无人驾驶飞行器控制系统设计

为了满足无人驾驶飞行器在空中飞行时的角度控制需求,引进5G网络对飞行器控制系统展开深入研究.通过设计STM56Y201GVH6单片机、RC接收器选型,完成系统硬件结构规划.构建无人控制飞行器姿态动力学模型,设计飞行器飞行姿态与角速度回路控制律,实现对无人驾驶飞行器的有效控制.在5G网络环境下选择F-13型号的无人驾驶飞...     

基于Tiva C系列处理器的四旋翼飞行控制系统设计

本文主要对四旋翼飞行控制系统进行了研究,设计了一款基于德州仪器Tiva C系列处理器的四旋翼飞行控制系统,该系统以TM4C123G微处理器为核心,九轴传感器MPU9250和气压传感器BMP280等作为姿态检测部分,包括处理器模块、姿态检测模块和电机驱动模块、电源模块等,采用四元数互补滤波算法作为姿态解算算法,以PWM控制的方式实现对飞行器的控制。     

四旋翼飞行器模型参考自适应容错控制

针对四旋翼飞行器执行器发生故障同时存在扰动时的姿态控制问题,设计了一种基于模型参考自适应(MRAC)的容错控制器。通过分析四旋翼飞行器的动力学特性,将执行器故障以加性因子的形式加入系统模型中,得到执行器故障下的动力学模型。所设计控制器的自适应律由参考模型和执行器故障下的模型的误差信号驱动,可实现较好的姿态控制。利用Lyapunov的分析方法证明了所设计控制器的渐进稳定性,最后在Matlab下进行了仿真实验。仿真结果表明,系统能克服扰动且在执行器故障下可良好地跟踪参考姿态角,验证了该算法的可行性和有效性。     

基于积分滑模控制的飞行器主动容错控制技术研究

基于容错控制和积分滑模控制理论的研究,对飞行器姿态进行控制,使其具有容错性能。飞行器模型考虑一类具有不确定性以及可能存在执行器故障的非线性系统,针对该系统设计积分滑模控制器,使系统即使在执行器故障情况下也能保持较理想的控制特性。同时也对该系统分别设计基于Lyapunov直接法和常规滑模理论的控制器,便于仿真验证中作为比较。在有无执行器故障的情况下,观察3种控制对状态变量的影响效果,比较常规滑模和积分滑模控制下的抖振情况,结果表明积分滑模控制在控制效果和减弱抖振方面表现更好。     

一种现代航天器飞行控制系统及其容错技术研究

阐述了一种现代航天器飞行控制系统的组成原理及其类别,阐述了时分复用和波分复用的性能特点,进一步提出了光纤多路发送软件、接收软件的设计技术。在详尽介绍容错技术的基础上,设计了一种现代航天器飞行控制系统三余度容错技术方案。实例仿真验证表明,本文所设计的现代航天器容错系统是可行的,并具有很强的鲁棒性。     

四旋翼无人机的自适应容错控制

针对四旋翼无人机在飞行过程中发生执行器故障和受到外界干扰的问题,提出了一种基于自适应方法的容错控制方案。将执行器故障以乘性因子的形式加入到系统模型中,同时采用单位四元数法描述系统姿态;考虑到位置子系统欠驱动的特性,引入虚拟控制力,同时解算出目标姿态和输入推力;针对同时存在执行器故障和外界干扰的位置和姿态子系统模型,利用自适应的方法设计了容错控制器,保证了对目标姿态的跟踪。最后,仿真结果验证了该系统控制器的有效性和稳定性。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.