Development of a Reconfigurable Platform for Manufacturing Equipment Control

In modern manufacturing equipment control area,controller is required to deliver higher computing capability for adopting advanced algorithms to meet speed and accuracy requirements,and reconfigurabilities for changing or(and)adding features or functions.This paper presents a methodology in design and implementation of a high performance and reconfigurable platform for manufacturing equipment control.This methodology is in virtue of system on a programmable chip(SoPC)technolo- gy but replacing the on-chip processor by an external high performance,floating-point digital signal processor(DSP).The appli- cation of the DSP is designed as a multi-threaded framework,which has more flexibilities than a traditional single-loop one.Fur- thermore,the field programmable gate array(FPGA)system can be reconfigured easily and quickly to meet a new requirement by dragging and dropping pre-built components in a SoPC building environment.As a result,the controller platform is more recon- figurable in terms of algorithms and functions.This platform is implemented in a 3-axis milling machine control and the result indicates that the design and implementation presented in this paper is feasible.     

Associative Learning Improves Visual Working Memory Performance.

The ability to remember visual stimuli over a short delay period is limited by the small capacity of visual working memory (VWM). Here the authors investigate the role of learning in enhancing VWM. Participants saw 2 spatial arrays separated by a 1-s interval. The 2 arrays were identical except for 1 location. Participants had to detect the difference. Unknown to the participants, some spatial arrays would repeat once every dozen trials or so for up to 32 repetitions. Spatial VWM performance increased significantly when the same location changed across display repetitions, but not at all when different locations changed from one display repetition to another. The authors suggest that a major role of learning in VWM is to mediate which information gets retained, rather than to directly increase VWM capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monte Carlo Simulation of Electron Swarm in the Diamond Film Growth via EACVD

Monte Carlo simulations are adopted to study the electron transport porcess in the non-uniform electric field.Some important parameters of electrons in diamond films dynamic process at low temperature via EACVD such as angle distribution,energy distribution,average energy of electrons are given.The results indicate that the electron scattering near the substrate is mainly of a large-angle scattering,exhibiting a double-peaking distribution .All of the conclusions provide some theoretical data referential to the vapor dynamic model of diamond film growth at low temperature via EACVD.     

新型焊接机控制算法研究

超声波焊接机控制软件是国内外生产微电路芯片厂家自动化流水线的不可缺少的一部分．为了提高生产微电路芯片的焊接速度，我们对超声波焊接机工业控制软件的算法进行部分优化．采用单台PC机，代替3个CPU控制3台步进电机．根据步进电机工作的特性曲线，计算出单台步进电机运行的时间控制数组，利用一个相对时间控制数组同时对3台步进电机进行控制．     

基于VB的上位机与FPGA /CPLD器件的通讯

介绍了基于VB的上位机与基于VHDL的FPGA／CPLD器件的通讯过程。通讯过程中，可以设置更高的波特率，通过巧妙的选取取数时刻，避免了误差。设计完成后该模块可以被其他系统重复使用。仿真结果表明，设计简单实用。     

Direct current bias applied to hot flame diamond deposition produces smooth low friction coatings

As-deposited diamond coatings generally have a high surface roughness which results in a high friction coefficient and extensive wear of the counter material in sliding contact. Therefore several methods for smoothening diamond coatings have been proposed, such as laser polishing, molten metal etching, thermochemical polishing and mechanical polishing. All these methods have some disadvantage e.g. long processing time or high processing temperature. Furthermore, they are all post-deposition treatments i.e. the manufacture of these coatings requires at least two processing steps, deposition and smoothening. With the present method which combines d.c. bias with hot flame diamond deposition, a smooth diamond surface is produced during the actual growth of the film. No post-deposition treatment is necessary. The surface roughness is not dependent on the coating thickness which means that thick coatings with smooth surface can be produced. In fact, the method has a smoothening effect, i.e. rough surfaces can be made smooth. The method is comparable to conventional hot flame deposition of diamond as to growth rate and cost of producing the coatings. The coatings have a nano-crystalline structure and a surface roughness of Ra = 25 nm, and result in a friction coefficient of 0.1 or less in dry sliding and about 0.05 in water-lubricated sliding against cemented carbide. Their wear resistance is virtually the same as that of conventional diamond films.     

小型静态CT用多焦点X射线源电子束偏转系统研究

第5代全静态电子束CT（EBCT）能在被检测物体、射线源和探测器均处于静止状态下完成CT扫描成像。这种EBCT成像方式既可应用于粉体材料、生物活体样品等易形变物体的CT检测,又可应用于物流包裹、在役管线等的快速CT检测。高精度的电子束偏转系统是静态CT成像多焦点射线源的关键技术之一。本文基于麦克斯韦电磁场相互作用理论,探讨了电子束在均匀磁场、小偏转角、近轴区域内的散焦、畸变及灵敏度特性,研究了影响电子束扫描系统焦点位置重复精度的物理参数及电子束在靶平面上的扫描偏转量与偏转线圈电流的线性关系。并设计、加工制作了一种小型高精度多焦点X射线的电子束偏转扫描系统,实验采用直径0.1 mm标准针规电子束扫描DR投影图像序列,验证了电子束偏转系统有良好的偏转线性,偏转量正比于O点的磁场强度,而与电子束的位置等初始条件无关。实验通过电子束偏转系统控制电子束偏转扫描,获得了熔断式保险管（Ø100 μm）的250个 X 射线视角投影,完成了第5代全静态三维CT重建图像。     

低温核供热堆保护系统的研究

高可靠性的保护系统是核供热堆安全可靠运行的重要保证。本文介绍了围绕核供热堆保护系统所开展的设计和研究工作。着重讨论了核供热堆的安全特性;保护系统的功能,保护参数的选择以及保护系统的基本结构。最后简要介绍了目前正在进行的一种新型保护系统的设计方案。     

基于红外焦平面阵列读出结构的非均匀校正算法

空间固定图案噪声严重影响了红外探测器的成像质量,它主要是由于焦平面阵列上各探测单元对于同一辐照的光电响应不完全一致所造成。另外,多通道图像数据采集电路的非均匀性更加重了这种噪声。本文提出了一种基于红外焦平面阵列读出结构的非均匀校正算法,它将校正过程分成两步。首先利用恒定统计方法滤除由通道放大器引起的固定图案噪声,然后再将处理结果通过改进的神经网络方法,进一步校正由探测器响应而产生的非均匀性。由于该算法是递推进行,并且具有收敛速度快、计算复杂度低等优点,因此易于工程实现。文中详细阐述了算法的基本原理及其流程,并用仿真数据和真实红外数据对算法性能进行验证,取得了较好的效果。     

一种数字式光伏阵列模拟系统的研究

针对模拟式光伏阵列模拟器的缺点,提了以光伏电池数学模犁为基础,由直流斩波器构成的数字式光伏阵列模拟器.该模拟器可以模拟任意太阳辐射强度、环境温度的光伏阵列1-V特性.实验结果证明该模拟器的输出特性非常接近实际情况,并且动态响应良好.