CRT显示器件中超大角度偏转的理论研究

CRT具有颜色逼真、分辨率高、技术成熟等优点，为了克服其体积大、笨重的不足，增加电子束偏转角度已经成为CRT的发展趋势。本文对超大偏转角的偏转线圈进行了理论研究，优化了线圈绕线分布和校正磁铁位置，减小光栅畸变和会聚误差。最后本文得到超大偏转线圈工作特性的理论极限。该研究结果可为超大偏转角CRT的研发提供理论指导。     

光点与会聚测试系统的设备需求与配置

光点测试和会聚测试是验证CPT电子枪偏转线圈性能的重要手段之一。本文提出基于合理的测试方法、有效适当的测试设备 ,建立最佳的测试系统。针对光点测试和会聚测试系统中的各种设备 ,介绍它们的应用原理及应用效果 ,从而了解在测试CPT光点质量和会聚误差过程中测试系统的设计原理及设备配置原理     

光点与会聚测试系统的设备需求与配置

光点测试和会聚测试是验证CPT电子枪偏转线圈性能的重要手段之一。本提出基于合理的测试方法、有效适当的测试设备，建立最佳的测试系统。针对光点测试和会聚测试系统中的各种设备，介绍它们的应用原理及应用效果，从而了解在测试CPT光点质量和会聚误差过程中测试系统的设计原理及设备配置原理。     

基于CCD的CDT电子束着屏误差自动测试系统

利用CCD图像传感器和图像采集处理技术,实现了电子束着屏误差二维自动测量。在荧光屏的前端附加垂直和水平两组微偏转线圈,通过控制微偏转线圈的电流,改变着屏点附近的磁场,使电子束着屏点的位置在一个粉点范围内精确连续可调。标准光栅的测试验证,系统绝对误差小于5m,表明该系统稳定可靠,一致性好。     

一种新型彩色显像管会聚测量系统

本文在系统分析会聚测量方法的基础上 ,着重对我们开发的一套新型的会聚测量设备进行了介绍和研究。该系统采用栅极脉冲电流、脉冲偏转 ,用微移动法消除荫罩影响修复光点。整套系统由计算机控制、采集、分析。该系统很好地满足了CRT研究开发的需要     

内偏转彩色显像管

对内偏转彩色显像管技术进行了详细论述。分析了材料的真空放气特性对阴极寿命的影响。由于偏转线圈放在管内 ,不能用传统的管球与线圈装配程序进行装配。为了得到好的着屏和会聚质量 ,设计了特殊的装配步骤。给出了 14英寸和 2 1英寸电视机 (TVTs)用以及 2 1英寸彩色监视器 (CMTs)用内偏转管的分析测试结果。     

25英寸700线彩色显像管偏转线圈的优化设计

在组合法计算彩色显像管偏转系统的基础上，对25英寸700线彩色显像管所用偏转线圈进行了优化设计。选取荧光屏光栅结点上的像差作为优化目标函数，选取线圈调制极上绕线密度的傅里叶展开系数作为优化参数，采用分步阻尼法优化设计出了25英寸700线彩色显像管用偏转线圈。根据实际的实验条件，绕制了25英寸700线彩色显像管用垂直偏转线圈，并与已有的25英寸同类彩色显像管所用偏转线圈进行了比较和分析。     

光栅位移测量系统的误差自修正方法研究

文中介绍的误差自修正方法是通过光栅位移测量系统中单片机对光栅传感器的多个零位信号进行计数,并根据测量值和系统设定值得到的误差函数自动进行误差修正.实验结果表明,该方法对光栅位移测量系统的误差既可自动进行有效的修正,又可提高系统的测量精度.     

修正万工显光栅数显的示值误差

在万能工具显微镜上运用回归分析法，建立修正光栅数显示值误差的数学模型，并编程补偿测量结果，方法简便易行，有效地保证了测量系统的准确度。     

光栅纳米测量中的系统误差修正技术研究

详细研究了光栅纳米测量系统的误差特性 ,以及利用激光干涉仪对高精度光栅测量系统的系统误差进行检测、并在信号处理中予以补偿和修正的方法。实验表明 ,通过这种系统误差修正方法对周期累计误差和细分误差同时进行修正 ,能够大幅度地将计量光栅系统的测量准确度从微米或亚微米量级提高到纳米级水平 ,以实现光栅纳米测量。     

A Calibration of Instruments with Non-Random Errors

The problem of calibration of instrrrments where measurement errors can be described as the sum of random walk and an independent observational error, is considered. Calibration policies, which are relevant to this error structure, are discussed, and comparisons between alternative methods are made.     

同轴度误差的解析评定法与仿真研究

在介绍符合定义的同轴度误差解析评定法的基础上，着重对该方法进行了仿真研究，分析了安装误差、测量系统中的直行运支误差及其对仪器回转轴线的闰行度误差等对同轴度误差测量结果的影响。文中建立的同轴度误差解析评定数学模型和得出的结论为同轴度误差测量信和在线测量系统的研究提供了理论基础。     

Probabilistic Modeling of Errors from Structural Optimization Based on Multiple Starting Points

With optimization increasingly used in engineering applications, a series of optimization runs may be required, and it may be too expensive to converge them to very high accuracy. A procedure for estimating average optimization convergence errors from a set of poorly converged optimization runs is developed. A probabilistic model is fitted to the errors in optimal objective function values of poorly converged runs. The Weibull distribution was identified as a reasonable error model both for the Rosenbrock function problem and the structural optimization of a high speed civil transport. Once a statistical model for the error is identified, it can be used to estimate average errors from a set of pairs of runs. In particular, by performing pairs of optimization runs from two starting points, accurate estimates of the mean and standard deviation of the convergence errors can be obtained.     

A study on the convergence of least‐squares meshfree method under inaccurate integration

In the authors' previous work, it has been shown through numerical examples that the least‐squares meshfree method (LSMFM) is highly robust to the integration errors while the Galerkin meshfree method is very sensitive to them. A mathematical study on the convergence of the solution of LSMFM under inaccurate integration is presented. New measures are introduced to take into account the integration errors in the error estimates. It is shown that, in LSMFM, solution errors are bounded by approximation errors even when integration is not accurate. Copyright © 2003 John Wiley & Sons, Ltd.     

二维精密工作台离散点测量结果误差分离的新方法研究

针对测量结果中包含的误差,提出一种能够分离精密工作台系统误差的方法。首先利用辅助测量栅格板和二维精密工作台的不同位置进行测量,然后根据栅格板上标记点的测量数据和标称值建立误差分离的数学模型,最终实现对测量结果的误差分离。通过仿真验证了算法的有效性。仿真结果表明:当不存在测量噪声时,能够实现误差的完全分离;当存在测量噪声时,计算值与给定值标准差的相对误差在X轴和Y轴上分别为1.95%和1.52%。对于不同幅度的噪声,工作台系统误差计算值稳定。该算法对噪声不敏感,表现出很好的鲁棒性,可用于测量结果和仪器性能的评价。     

基于误差信号的双模式遗传盲均衡算法研究

DD算法具有收敛速度快,稳态剩余误差小的优点,是一种最常用的盲均衡算法。遗传盲均衡算法是一种新的盲均衡算法,它利用遗传算法来解决盲均衡问题,具有较好的全局优化特性。在综合研究了DD算法及遗传盲均衡算法的特性后,利用误差信号的特性,给出了一种新的双模式遗传盲均衡算法,有效的结合了DD算法以及遗传盲均衡算法的优点,大大提高了算法的运算速度,提升了收敛性能,解决了遗传盲均衡算法运算量大的问题,并通过计算机仿真验证了该算法的有效性。     

Reducing number entry errors: solving a widespread,serious problem

Number entry is ubiquitous: it is required in many fields including science, healthcare, education, government, mathematics and finance. People entering numbers are to be expected to make errors, but shockingly few systems make any effort to detect, block or otherwise manage errors. Worse, errors may be ignored but processed in arbitrary ways, with unintended results. A standard class of error (defined in the paper) is an ‘out by 10 error’, which is easily made by miskeying a decimal point or a zero. In safety-critical domains, such as drug delivery, out by 10 errors generally have adverse consequences. Here, we expose the extent of the problem of numeric errors in a very wide range of systems. An analysis of better error management is presented: under reasonable assumptions, we show that the probability of out by 10 errors can be halved by better user interface design. We provide a demonstration user interface to show that the approach is practical.

To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact.(Charles Darwin 1879 [2008], p. 229)

     

电子天平零点误差的确定及应用

按照电子天平检定规程的要求,所有示值误差应是对零点误差修正后的修正误差,但规程并没有给出零点误差测试的方法,因此,如何确定电子天平的零点误差,长期困惑着从事天平计量的工程师。本文旨在探讨电子天平零点误差的确定方法,以用于电子天平检定/校准过程中对示值误差的修正,从而满足规程的要求。     

Modelling and compensation of fixture locators’ error in CNC milling

Fixture errors are one of the error sources in machining operations. The fixture errors consist of positioning inaccuracies and errors due to workpiece and fixture deformations. Fixture locators’ height error causes incorrect positioning of the workpiece in the fixture and inaccuracy in machined surfaces which can be much more than the locators’ height error. For machining precise workpieces, it is necessary to eliminate these errors. This paper presents a method for modelling and compensating the fixture locators’ height error effect on workpiece machined surfaces. In this method, the planes of workpiece actual coordinate system (ACS) are mathematically modelled in the workpiece theoretical coordinate system (TCS). Using the model, required homogenous transformation matrix for coinciding ACS with TCS and modifying machining toolpath for compensating the errors is generated. The presented model is used to develop a post-processing fixture locator error compensation module, which can modify CNC machining codes to eliminate the effect of fixture locators’ height error on the workpiece machined surfaces. For verifying the presented method, machining simulations and cutting experiments have been performed in this work. The results show that the method can eliminate the effect of fixture locators’ height error on the workpiece machined surfaces considerably.     

基于原始误差项快速辨识的空间几何误差补偿

在误差补偿中,误差项辨识和误差补偿一直是研究的重点,国内外许多学者对此开展了许多工作,但总的来说,仍然缺乏一种高精度并能够快速获得机床几何误差信息的测量仪器．目前的误差补偿方法,由于机床误差产生的原因很多,难以找到合适的通用数学模型进行误差分解,故难以推广应用．本文设计并实现了一种基于原始误差项快速辨识的空间几何误差补偿方法,使得在精度等级稍低的机床上实现更高精度等级加工的效果．