<Emphasis Type="Bold">Simultaneous Parameter and Tolerance Design for an Electronic Circuit Via Computer Simulation and Statistical Optimization</Emphasis>

Conventionally, parameter design is carried out prior to tolerance design for economic reasons. However, a combined parameter and tolerance design may be completed in one stage for further cost reduction and quality improvement. In this study, a simultaneous optimization of component parameter and component tolerance for an electronic circuit design is realized via computer simulation and Response Surface Methodology (RSM). The approach first generates a set of outputs (experimental data) through computer simulation based on various combinations of parameter and tolerance levels as inputs. Then these outputs are converted into a total cost as a response value before applying RSM for statistical analysis and optimization. The response value(total cost) includes quality loss, tolerance cost, and failure cost, which reflect the combined effect of the assigned parameter and tolerance values being assigned. In this study, computer simulation can be carried out by two methods. The first method uses Monte Carlo Simulation to generate the outputs with the condition that the transfer function is known. The second method uses a Pspice simulation program to generate outputs without necessarily knowing the transfer function. The results provide designers with the optimal component parameter and tolerance values, and the critical components, and the response function – all of which are very important during the early design activities as they enable designers to have a repeated application, accurate feedback and appropriate suggestions, particularly under uncertain design conditions.     

烟草异物剔除系统中高速皮带机风压系统的流场有限元分析

首先简要介绍了烟草异物刷除系统中高速皮带机风压部分的作用及重要性,接着建立了其简化的几何模型和流场有限元分析模型,分析了四种工况下流场的速度和压力分布情况,得出风压系统中的压风和托风都是必需的。然后对压风口和托风口的宽度及风速变化对流场的影响进行了分析和评价,最后据此给出了压风和托风的最佳参数组合。     

棱体成形车刀CAD系统设计与研究

采用了AutoCAD的嵌入式开发语言AutoLISP，以AutoCAD2002forWindows为开发平台，研制开发了棱体成形车刀参数化CAD系统，设计了各功能子模块，完成了图形用户界面设计、参数计算程序设计，建立了自定义函数库、数据管理系统和图形系统。该系统能够准确、快捷地完成棱体成形车刀的设计计算并生成工程图。     

一种基于DSP结构的电解质分析仪的设计与实现

针对电解质分析的特点，提出一种智能仪器的新型实用方案设计。介绍了基于DSP为核心的电解质分析仪器的系统设计思想，阐述了实时测量的实现方法。这种分析仪器可批量、连续测量多组样品中的离子成分及含量。并能针对具体问题进行参数优化，使得测量的稳定度和精度能够满足使用要求。     

机械系统动力学参数动态测试的频域辨识法

提出了机械系统动力学参数动态测试的频域辨识法。该法的要点为：计算机产生多谐差相激振信号，在该信号激励下机械系统产生与激振信号同周期的振动响应，对激励信号和响应信号作等间隔采样并作快速富里哀变换（ＦＦＴ），获得的频谱代入机械系统的频域动力学方程，再用最小二乘法辨识出各参数。由于富里哀变换将时域内的微分运算转变成频域内的代数运算，从根本上避免了噪声的微分放大作用，并且由于对信号整周期截断时ＦＦＴ具有理想的选频滤波特性，所以该法具有很强的抗干扰性。本文以动力调谐陀螺的挠性接头为例，用仿真计算验证了该法的有效性。     

Parameter extraction of solar panels using the graphical method

ABSTRACT

An effective approach to extract the loss parameters of solar panel is developed and able to accurately represent their electrical behaviour. This method allows extracting the parameters of the single-diode model using only the information provided by the manufacturer's datasheet with a low-cost parameter determination technique and no complexity. The complete equation of the single- diode model of solar cells and panels is used, where the number of parameters to be calculated is reduced only to two parameters by a transcendental equation exclusively connecting the series resistance and the diode current, which is solved using the graphical method. The accuracy of the presented approach is justified by experimental data. In addition, the results of the proposed procedure are compared to the most recent proposed techniques in the literature. Furthermore, the results show a highly accurate; in particular, at the maximum power point, the error is still much less than 0.01%.     

基于相空间重构理论的电力负荷预测

研究电力负荷预测问题。针对电力负荷既受非线性变量的影响又受自身混沌性质的影响,单一预测方法无法同时完善地映射其复杂关系,导致预测精度较低。为进一步提高电力负荷预测准确度,融合相空间重构理论与支持向量机,提出了一种人工智能的新电力负荷预测方法(PSR-SVM)。首先以对数线性平稳法对初始电力负荷数据进行去趋势处理。然后基于粒子群算法对相空间重构参数与支持向量机参数进行同步优化,以最优延迟时间τ和嵌入维m进行电力负荷序列相空间重构,并以支持向量机及其最优参数构建非线性电力负荷预测模型。最后以某电力公司1978～1998的电力负荷进行仿真,结果表明,新模型预测精度明显高于参比模型,是一种高精度、可行的电力负荷预测方法。     

并行遗传算法在器件模型参数提取中的应用

器件的模型和模型参数提取是电子设计自动化(EDA)领域的关键工作。采用遗传算法进行器件模型参数提取工作是近年来兴起并被广泛使用的一种参数提取方法。本文讨论了并行遗传算法的特点,针对遗传算法自身的耗时问题,提出了基于MPI的主从式遗传算法,并证实了并行计算在参数提取工作中的可行性。该方法简单易用,显著提升了MOS器件模型参数提取的速度。     

基于经验整定公式的自适应PID控制算法研究

PID控制虽应用广泛,但其参数整定一直都是件困难的工作,更重要的是即使参数整定完成,因其不具有自适应能力,当环境变化时,PID的参数需要重新调整。传统的自适应PID控制算法由于算法的复杂性及工程应用的实际问题,它的应用受到一定的局限。本文设计了一种基于经验公式整定的自适应PID控制器。针对300MW循环流化床进行升负荷实验,实验结果表明,经验公式整定下的自适应PID控制效果较佳,具有较好的鲁棒性,而且容易在实际工程中实施。     

基于模糊 ARTMAP 网络的速率

目的介绍了一种速率陀螺故障检测与诊断的方法.方法通过统计检验滑动窗口的残差,再采用模糊ARTMAP网络直接对模型参数进行分类.结果该方法不但能正确诊断出已知的速率陀螺故障,还能检测出未知的故障.结论该方法避免了一般前向网络在分类中的不足,对可能发生的故障能进行有效地检测与诊断,且不用求解系统的物理参数.