数字永磁同步交流伺服系统

数字永磁同步交流伺服系统以DSP＋CPLD为处理核心．由控制处理器电路、验动控制电路、驱动接口电路和功率放大电路组成。本系统采用空间电压矢量脉宽调制技术,实现三相永磁同步电机的控制。本文介绍了数字交流伺服系统的实现原理、硬件和软件设计。     

永磁同步电机的零低速无传感器控制研究

文中介绍了基于高频注入法的无位置传感器控制实现了永磁同步电机初始位置的估计,控制系统采用了先进的控制策略:矢量控制策略和SVPWM(电压空间矢量脉宽调制技术),基于MATLAB/SIMULINK搭建了仿真模型,结果证明了基于高频注入法实现永磁同步电机无位置传感器控制系统算法上的有效性。     

基于空间电压矢量的永磁同步电机恒转矩控制方法研究

针对矢量控制和直接转矩控制两种控制策略,本文研究了永磁同步电机空间电压矢量调制直接转矩控制方法,并采用空间电压矢量调制直接转矩控制策略对永磁同步电机进行了恒转矩控制的模拟仿真,提高了控制系统的稳定性。     

高速电主轴永磁同步电动机的矢量控制算法研究

随着工业技术的发展，永磁同步电机因其高精度且超高速等优点而被广泛应用，针对高速电主轴永磁同步电动机的矢量控制，结合永磁同步电机特点，采用基于电流双闭环的无位置传感器控制方法，再通过对转子位置的开环估计，实现了对高速永磁同步电动机的无传感器矢量控制。仿真分析和试验结果显示，该矢量控制方法准确性高、稳定性好。     

电动汽车车载空调变频器设计与实现

本文介绍永磁同步电机应用于电动汽车的优势,建立了以sTM32F103为核心的车载空调永磁同步电机矢量控制系统,介绍系统的软硬件设计流程与具体实现方法。试验结果表明,该空调变频器设计方案能满足空调压缩机的驱动控制,具有可行性与实用性。     

基于片上可编程系统的永磁同步电机控制器的设计与实现

针对永磁同步电机损耗少、效率高等特点,设计了一种基于片上可编程系统的永磁同步电机控制器,以FPGA为载体,Nios Ⅱ为中央处理器,数据采集接口作为片上外围设备,并使用DSP Builder工具实现基于模型的空间矢量控制算法模块,组成完整的片上系统,实现电流、速度和位置的精确控制。工程实践结果表明,基于SoPC技术的永磁同步电机控制器能够达到高精度、快响应的稳定控制效果。     

基于SVPWM的永磁同步电机直接转矩控制系统的研究

将空间矢量脉宽调制技术(SVPWM)引入到了永磁同步电机的直接转矩控制(DTC)当中,实现了电压空间矢量的连续调节。定子磁链近似为圆形,有效地解决了常规DTC系统电磁转矩脉动较大的问题。在MATLAB/Simulink环境下搭建了永磁同步电机基于SVPWM的直接转矩控制系统的模型,对电机的多种运行状态进行了仿真,验证了控制理论的正确性和有效性。     

变频空调变频调速系统的研究

文中提出了一种基于SVPWM的变频空调变频调速系统的方法,首先介绍了永磁同步电机的数学模型,空间矢量脉宽调制(SVPWM)的基本原理及实现方法,并在MATLAB环境下应用Simulink及Sim Power Systems工具箱建立了永磁同步电机控制系统的速度和电流双闭环仿真模型,进行了实验仿真,仿真结果表明:永磁同步电机矢量控制系统具有较好的动态响应特性和速度控制特性,使PMSM达到与直流电机近似的控制效果。该方法为分析和设计变频空调的变频调速系统提供了新的手段和工具,相比传统的变频空调,效率更高,性能更好。同时也为实现变频空调的数字化变频调速提供了新的思路。     

基于TMS320F28335的永磁同步电动机控制器的设计

针对永磁同步电机（PMSM）具有结构简单、效率高、功率因数高等优点,研究和设计了一款以浮点型TMS320F28335数字信号处理器（DSP）为控制核心的永磁同步电机控制器。该控制器设计了三相全控桥式功率驱动电路和过流、欠压检测,温度监控等检测保护电路。能通过CAN总线连接外部显示模块以及RS232通信接口与上位机的高速通信并进行实时数据交换,软件部分采用空间矢量算法实现电流、速度和位置的精确控制。实验结果表明,控制器精度高、响应快、控制效果稳定。     

永磁同步电机直接转矩控制系统的仿真研究

文章分析了永磁同步电机直接转矩控制的原理,阐述传统直接转矩控制系统转矩脉动的缺点,本文将空间矢量脉宽调制技术引入永磁同步电机的直接转矩控制系统中,利用空间矢量的调制过程,可在相同的系统硬件条件下得到更多的、连续的电压空间矢量,进而得到对电机更准确的控制。仿真结果表明,该方案既保持了直接转矩控制快速动态响应,又减小了电机转矩的脉动。     

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.