FPGA在小卫星姿态控制系统中的应用

为了提高卫星姿态控制的运行速度,减轻星栽计算机的负担,提出了一种基于FPGA实现卫星姿态控制器的硬件算法.在Matlab/Simulink环境下建立卫星的运动学和动力学方程,给出了经典PID的模拟控制算法.在此基础上推导了数字PID控制算法,并采用状态机的设计方法实现该控制器的设计,应用VHDL硬件语言进行编程.最后,通过调用Matlab的Serial串口对象,将模拟的卫星动力学姿态与FPGA开发板交换控制信息.基于FPGA的PID控制器对整个系统进行控制,最后的仿真结果证明了该方案的可行性和准确性.     

基于可编程器件的模糊控制器

介绍了用硬件描述语言(VHDL)设计的一种新型的模糊控制系统，这种模糊控制器具有快速、修改方便的特点，给出了设计的框图和有关程序，并用FPGA来实现。     

模糊自整定PID控制器的FPGA实现

提出了一种基于VHDL描述、FPGA实现的模糊自整定PID设计。首先对模糊增量式数字PID的算法进行了介绍和数学推导,然后使用自顶向下的设计方法完成了控制器的VHDL分层设计,最后,在一个具体的FPGA芯片上实现了该控制器。由于采用了离线计算、在线查表的模糊自整定参数技术和增量式PID算法,本设计既降低了FPGA的资源耗费,又改善了传统PID控制器的控制性能。     

基于FPGA+VHDL的温度控制系统设计

温度检测和控制系统在实际中有着广泛的应用,如温室的温度控制等.本文介绍了一种基于FPGA VHDL的温度控制系统设计.可编程器件(CPLD/FPGA)和硬件描述语言VHDL的出现使得数字电路的设计周期缩短、难度减小.系统采用FPGA作为核心控制器件和VHDL进行编程,设计采用模块化思路:分别实现各个模块(包括温度检测、键盘输入、温度显示和控制),再加以整合实现整个系统,达到了温度控制的目的.     

基于FPGA的电梯控制器设计

使用FPGA器件作为主控制芯片,采用模块化设计方法,通过硬件描述语言VHDL对电梯控制器各功能模块进行编程,实现了六层电梯控制器设计。经软件仿真和硬件实现,结果表明该方案能满足设计要求,并能扩展到多层电梯,有较强的实用性。     

基于FPGA的片上网络虚拟通道控制器的设计

虚拟通道控制器的设计是实现虚拟通道技术的关键.基于FPGA实现技术,利用VHDL硬件描述语言设计实现了一种适用于网格、半环网、环网三种拓扑结构的虚拟通道控制器.该虚拟通道控制器工作频率能够达到689MHz,FPGA资源占用率仅为1%,是一种高效的虚拟通道控制器设计方案.     

双压电膜驱动微小机器人控制器的研究

设计了一种适用于双压电膜驱动的微小型机器人控制器.控制器主要由信号发生电路及高压放大电路组成.信号发生电路采用直接数字信号合成器(DDS)技术及静态随机存储器(SRAM)内存查表技术,利用硬件描述语言(VHDL)和原理图描述方法对现场可编程门阵列器件(FPGA)进行设计,产生的信号通过集成功率运算放大器对机器人进行驱动控制.最后进行了控制器性能测试,完成了该控制器样机的试验.     

基于FPGA的模糊PID控制器设计

针对模糊PID控制器多为单片机技术的软件实现,其实时性与抗干扰性能不理想,采用以FPGA作为核心控制器,采用模块化思想,设计并实现模糊自适应PID控制器的硬件设计方案。实际运行结果表明,采用该方法可明显改善效果,在简化设计的同时,也可提高系统的实时性和抗干扰能力。     

SDRAM控制器的FPGA设计与实现

介绍了利用现场可编程门阵列(FPGA)实现同步动态随机存储器(SDRAM)控制器的方法,着重于FPGA具体实现过程中的一些常见问题.分析了设计中所用的SDRAM性能、特点,给出了其读写时序状态图,给出SDRAM初始化方式及其相应的模式设置值,并根据本设计的实际情况对SDRAM状态机进行了简化,给出了一种相对容易实现的SDRAM状态机.本设计采用甚高速集成电路硬件描述语言(VHDL)编程,直观而且占用资源较少,其基本设计原理对其他同类SDRAM也适用,对需要大容量存储器的应用是较经济的设计.     

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.     

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.     

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.     

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.     

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.     

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.     

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.