滑模观测器和比例积分的超机动动态逆控制

研究了一种基于Super-twisting算法的滑模观测器和比例积分的超机动飞机动态逆控制方法。首先分析考虑推力矢量下的超机动飞机非线性特性,建立飞机非线性仿真平台;然后在快回路中针对飞行环境下外部直接干扰力矩,采用Super-twisting算法的滑模观测器估计干扰力矩,设计补偿控制律进行干扰抑制;慢回路中采用经典的比例积分控制弥补由非线性对消引起的系统逆误差;最后对设计的控制律进行大迎角下的"眼镜蛇"机动。仿真结果表明,设计的控制律使超机动飞机具有良好的快速性和稳定性。     

基于滑模扩张干扰观测器的固定翼无人机动态逆控制

为解决存在模型不确定性与外部干扰时的固定翼无人机控制问题,设计了一种非线性滑模扩张干扰观测器与快速响应动态逆相结合的控制律。在扩张干扰观测器设计的基础上,引入滑模原理设计了一种非线性滑模扩张干扰观测器,对干扰及其变化率进行实时估计;将无人机姿态运动方程分为姿态角慢回路与姿态角速率快回路,依此分别设计动态逆控制律,并基于干扰估计量对未知扰动进行补偿,同时在快回路控制器中加入由快速跟踪微分器(TD)估计的指令值微分量,以提高控制器的响应速度,最后证明了复合控制器的稳定性。仿真实验表明,设计的复合控制器能够对无人机姿态运动进行高效控制。     

基于非线性干扰观测器不确定系统的终端滑模控制

针对一类存在非匹配干扰和建模误差的高阶非线性系统,结合滤波反步控制方法,设计一种基于非线性干扰观测器的自适应反步非奇异终端滑模控制方案。首先,设计一种有限时间稳定的非线性干扰观测器,以此对非匹配干扰进行估计和补偿。采用反步控制处理高阶不确定非线性系统,结合动态面控制设计虚拟控制律,避免传统反步设计中存在的"微分爆炸"问题;第n步结合自适应控制和非线性干扰观测器,设计非奇异终端滑模控制律,消除建模误差和非匹配干扰对系统的影响。基于Lyapunov理论证明跟踪误差一致最终有界。仿真结果验证了所设计控制方案的有效性。     

基于SMDO的非线性预测射击线稳定控制

针对一款海上武器随动系统的非线性、干扰未知性的难题,提出基于滑模干扰观测器(SMDO)的非线性预测控制策略,该复合控制策略利用滑模干扰观测器,对海浪波动、负载变化和系统不确定性等进行逼近,并依据观测器的输出进行前馈补偿和预测控制的模型修正,使得预测控制的滚动优化能够时刻保持在贴近实际系统的基础之上,从而实现提高整个控制策略性能的目的.在设计基于滑模干扰观测器的非线性预测控制器时,采用基于连续时间的非线性系统预测控制方法,与基于滑模干扰观测器相结合,最终设计出海上武器射击线稳定控制的复合控制律.仿真结果表明,该控制策略可以有效提高海上武器射击线稳定控制的抗干扰能力、打击目标精度以及海上武器动态稳定瞄准性能.     

基于NDO的单向辅助面滑模飞行控制

针对存在建模误差和外界干扰等不确定因素的飞行姿态系统,使用单向辅助面滑模控制与非线性干扰观测器(NDO)相结合的方法设计控制器。采用单向辅助面滑模控制方法设计标称系统控制器,而对于系统中的不确定性和扰动则利用NDO进行逼近,并将NDO的输出用于设计鲁棒补偿控制项,所设计的控制器可以有效削弱抖振且能够显著提高收敛速度。最后通过Lyapunov理论证明了闭环系统的稳定性,仿真结果也体现了良好的控制效果。     

一类非线性不确定系统的滑模反演控制

针对一类存在未知复合扰动的高阶非线性系统,提出一种基于有限时间干扰观测器的反演非奇异快速终端滑模控制方法。采用有限时间干扰观测器对复合扰动进行快速精确估计并设计控制器鲁棒项进行补偿。采用反演控制处理高阶非线性系统,结合动态面控制设计虚拟控制律;同时设计非奇异快速终端滑模控制律,提高系统的收敛速度和控制精度,并通过Lyapunov理论证明了系统跟踪误差一致最终有界。通过数值仿真验证了所提控制方法的有效性和可行性。     

基于改进干扰观测器的火箭弹姿态控制

针对旋转火箭弹非线性动力学系统中存在大量的非线性、多变量耦合及参数不确定等特点,提出一种改进非线性干扰观测器,对高频运动的干扰逼近特性进行观测,结合反演滑模控制,设计反演滑模控制器,并证明了系统的稳定性.最后通过仿真对传统观测器与改进观测器的性能进行比较,仿真结果表明,改进观测器具有较高的估计精度和较强的鲁棒性.     

高超声速飞行器积分型 Terminal 滑模控制设计

针对高超声飞行器模型参数不确定和外界干扰对姿态控制的影响,基于高超声速飞行器俯仰通道控制系统,提出一种新的 Terminal 滑模姿态控制方法。通过引入一阶滤波器,结合反演法,克服原来幂次形式引起的最终控制奇异问题;并通过设计的干扰观测器实时观测未知干扰,补偿控制器性能,应用 Lyapunov 稳定性理论严格证明了系统的稳定性,从而保证 Terminal 滑模控制器能有效提高系统动态特性。在气动参数标称与拉偏的情形下进行高超声速飞行器数字仿真,仿真结果说明干扰观测器能快速跟踪干扰,且所设计的 Terminal 滑模控制可以满足飞行器高精度的控制要求。     

干扰观测器补偿的四旋翼飞行器自适应离散终端滑模控制

传统的离散线性滑模应用于四旋翼飞行器控制具有跟踪误差大、响应速度慢、不能有限时间收敛等问题,针对具有外干扰、系统不确定和建模误差的四旋翼飞行器,提出了干扰观测器补偿的自适应离散终端滑模控制。首先,对一类包括四旋翼飞行器模型的离散化方程推导了终端滑模控制律,引入自适应律因子减小抖振,构造了以状态变量的平方作为干扰误差收敛速度的改进型离散干扰观测器,且证明了它的稳定性,再利用改进的离散干扰观测器获取未知干扰、不确定和建模误差的高精度估计,并用于控制器设计补偿项,提高鲁棒性和减小稳态误差,再对整个系统的稳定性做了严格的证明。最后将提出方法用于四旋翼飞行器控制,Matlab仿真分析表明,干扰观测器补偿的自适应离散终端滑模控制比离散终端滑模等其他控制方法具有响应时间更快、跟踪效果更理想、鲁棒性更强等特点,实现了在不确定干扰的情况下飞行器姿态的稳定控制。     

基于模糊干扰观测器的无人机自主着陆逆控制器设计

针对具有显著非线性和不确定性的无人机自主着陆系统,提出基于模糊干扰观测器的非线性动态逆的控制方法,用于降低控制器对不确定性的要求。基于时标分离原则,将无人机自主着陆系统分为快回路、慢回路、非常慢回路和极慢回路,通过在快回路、慢回路和非常慢回路设计动态逆控制律使状态解耦,设计直线下滑和指数拉平的着陆轨迹,并在极慢回路进行跟踪。设计基于模糊系统的干扰观测器,以逼近外部干扰和内部不确定性等复合干扰,基于李雅普诺夫理论证明系统稳定性。最后给出了无人机自主着陆轨迹跟踪控制仿真,仿真结果表明设计控制器具有良好鲁棒性,完成无人机在外界干扰下的自主着陆控制。     

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.     

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.     

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.     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.