基于临界比例度法整定PID控制器参数的仿真研究

PID控制器参数的整定是PID控制系统设计的核心。为了整定PID控制器参数,基于Matlab/Simulink仿真环境,采用临界比例度法整定PID控制器参数,通过仿真实例很好地实现了对PID控制器参数的整定。该仿真具有直接观察系统性能变化,快速、准确选择合适PID参数,充分体现了Matlab/Simulink直观、方便的特点。     

MATLAB/Simulink仿真在PID参数整定中的应用

针对PID参数整定过程的复杂性,基于MATLAB/Simulink仿真环境,模拟ZielogerNiclosls法PID参数整定的方法和步骤,给出了一种简单有效的PID参数整定方法。与通常的整定方法比较,其优点是非常直观、可以随意修改仿真参数,节省了大量的计算和编程工作量。通过仿真实例验证了该方法的有效性以及抗干扰能力。     

基于模糊PID皮革收缩温度测定仪控制系统设计

针对皮革收缩温度测定仪的温度控制系统的控制效果不甚理想的问题,提出一种参数模糊自整定PID控制方法,该方法集中了模糊控制和常规PID控制两种控制的优点.在重点介绍模糊PID控制器设计方法的基础上,利用Matlab软件分别进行了参数模糊自整定PID控制系统和常规PID控制系统的仿真实验.仿真实验结果比较表明,参数模糊自整定PID控制方法使该仪器的温控系统的性能得到很大改善.     

参数模糊自整定PID在飞机全电刹车中的应用

提出了一种参数模糊自整定PID的控制策略在飞机全电刹车系统中的应用。滑移率的偏差和偏差变化率作为控制器的输入,PID控制器3个参数的自整定值作为控制器的输出,实现了PID参数的在线自整定。分析了参数模糊自整定PID的原理。飞机全电刹车系统的仿真曲线表明:以滑移率为控制对象,参数模糊自整定PID控制与常规PID相比,控制系统的响应速度快、超调量减小、过渡过程时间大大缩短、振荡次数少,具有较强的鲁棒性和稳定性。     

基于模糊自整定PID的汽轮机数字电液控制系统

基于模糊控制技术和汽轮机DEH系统的数学模型,将模糊自整定理论应用于汽轮机DEH系统,设计了一种适用于汽轮机数字电液控制系统的模糊自整定PID控制器。他利用偏差及偏差变化率作为模糊控制器的输入,并制定了模糊规则进行控制,实现PID参数的实时自整定,从而改善汽轮机调节系统的控制特性。仿真结果和分析表明在调节稳定性,超调量和自整定PID参数等方面,模糊自整定PID控制算法均优于传统PID控制算法。     

基于PID参数自整定的液位控制系统设计及其实现

针对现有液位调控系统中双回路PID参数调节困难的问题,通过将继电反馈作为支撑PID参数自整定方法,设计了一套基于MCGS和PLC的液位调控系统用串级PID参数自整定控制策略。通过分析储油罐阶跃响应得到传递函数,在此基础上对控制对象进行离散化并建立了PID参数自整定控制系统,在MCGS平台成功实验了实时监控。比较自整定前后的控制性能,得到PID参数自整定具有较快的响应速度,较小的超调量、更快达到稳态、更强的抗干扰能力等优点,可以实现对储油罐系统液位的最佳控制。仿真结果表明PID参数自整定控制技术能够有效地调节储油罐系统的液位控制,极大地保证输油系统的安全。     

基于模糊PID参数自整定的温度控制系统的研究

工业温度控制系统具有非线性、时变性和滞后性等特性,严重影响温度控制的快速性和准确性,为了解决常规PID参数调节在温度控制中适应性差,调节效果不理想的问题,这里采用了模糊PID参数自整定控制方法,用模糊控制规则对PID参数进行修改,利用Matlab的Simulink仿真工具箱做了常规PID与模糊PID的仿真对比试验。仿真结果表明,模糊PID参数自整定控制效果在超调量和调节时间上都小于常规PID,提高系统快速性和准确性,改善了温度系统动态性能。     

基于模糊自整定PID的温控系统研究

针对非线性，大滞后的温控对象，提出了一种基于模糊自整定PID参数的控制方案，文中详细介绍了模糊推理的思路及PID参数的整定规则，并给出仿真分析结果。     

带Smith预估器的预测PID控制器的设计

设计了一种基于广义预测的思想的PID参数整定的改进算法。利用阶梯式控制策略,有效地减小参数整定中的计算复杂性,并能更方便地通过阶梯因子对所得PID控制器的控制性能进行调节。另外,文中对大延时系统的参数整定误差进行了分析,并通过引入Smith预估器改善了这类系统的参数整定效果。仿真实例说明了上述算法的有效性。     

一种实现系统PID参数实时整定与仿真的方法

工业现场PID控制器应用广泛,PID参数的整定直接影响控制器效果,如何整定PID参数变得尤为重要,应用OPC技术、利用Matlab进行实时仿真,使系统PID参数更能适应系统的生产过程。OPC技术作为一种开放式接口标准,其支持ActiveX技术,通过Matlab调用ActiveX控件,可以实现Matlab与OPC服务器进行动态数据交换,通过这种方法可以实现Matlab对工业现场生产实时数据获取。构造半实物仿真的系统。进行PID参数的实时整定,实现分段自适应,获得较好的鲁棒性。     

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.     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.