微处理器VRM的滑模控制技术研究

为了改善微处理器VRM(电压调节模块)输出电压的动态响应特性和稳态纹波及精度,简化VRM滑模控制器的设计过程,通过深入研究滑模控制VRM的相关文献,全面评述了VRM的滑模控制技术应用及研究,重点分析了系统抖振削弱,稳态误差减小或消除、瞬态响应速度提高、开关频率的固定和降低、切换面的构造和滑模系数的选取方法以及滑模控制器设计方法的研究现状和取得的研究成果.实验分析结果表明,滑模控制器是最适合电压调节模块的控制器,VRM未来的工作重点是滑模控制器的设计与实现.     

具有人机交互接口的家庭安全报警系统设计

针对市场上各类家庭报警系统没有为用户提供人机交互接口的弊端,在传统报警系统的基础上对其功能进行了有意义的扩展,既实现了对非法侵入、火灾、煤气泄漏等各类家庭紧急情况的及时报警,又为用户提供了人机交互功能,解决了用户不能自行修改报警号码的问题,使整个系统设计更加人性化.给出了整个系统的硬件结构框图和软件设计流程图.     

应用带补偿的机会约束规划策略优化精馏过程的研究

精馏过程优化存在许多不确定变量,其对优化结果的影响是不可忽略的,所以需要找到真实反映不确定变最的数学模型,找到最优的求解方法得到精确解,进而得到最优的优化结果.本研究通过分析随机规划策略和不确定因素的特性及其对精馏优化过程的影响,对不确定因素进行分类,应用带补偿的随机规划和机会约束规划实现不确定因素对优化目标和约束的影响.对于模型中的机会约束,由于不确定输入变量和不确定输出变量间存在单调关系,所以可以通过对不确定输入变量的多重积分将机会约束转化为等价地确定性非线性约束,此时模型转化为含有非线性约束的带补偿的随机规划模型,此模型通过改进的蒙特卡罗(Monte Carlo)积分和含有序列2次规划(SQP)的Benders分解相结合的混合算法有效的求解.所提出的求解方法借助于Matlab软件能够得到比较精确的结果.采用本文所提出的模型及求解方法对精馏塔操作的模拟实验过程进行优化研究,可以看出带补偿的机会约束规划模型能够很好地反映不确定变量对优化过程的影响.所以本文提出的模型和求解方法是有效可行的,且对于以后的不确定优化研究具有很好的指导意义.     

Labeling design documents based on operators’ consensus—A case study of robotic design

Designers usually begin with a database to look for historical design solution, available experience and techniques through design documents, when initiating a new design. This database is a collection of labeled design documents under a few of predefined categories. However, little work has been done on labeling a relatively small number of design documents for information organization, so that most of design documents in this database can be automatically categorized.This paper initiates a study on this topic and proposes a methodology in four steps: design document collection, documents labeling, finalization of documents labeling and categorization of design database. Our discussion in this paper focuses on the first three steps. The key of this method is to collect relatively small number of design documents for manual labeling operation, and unify the effective labeling results as the final labels in terms of labeling agreement analysis and text classification experiment. Then these labeled documents are utilized as training samples to construct classifiers, which can automatically give appropriate labels to each design document.With this method, design documents are labeled in terms of the consensus of operators’ understanding, and design information can be organized in a comprehensive and universally accessible way. A case study of labeling robotic design documents is used to demonstrate the proposed methodology. Experimental results show that this method can significantly benefit efficient design information search.     

Short text similarity based on probabilistic topics

In this paper, we propose a new method for measuring the similarity between two short text snippets by comparing each of them with the probabilistic topics. Specifically, our method starts by firstly finding the distinguishing terms between the two short text snippets and comparing them with a series of probabilistic topics, extracted by Gibbs sampling algorithm. The relationship between the distinguishing terms of the short text snippets can be discovered by examining their probabilities under each topic. The similarity between two short text snippets is calculated based on their common terms and the relationship of their distinguishing terms. Extensive experiments on paraphrasing and question categorization show that the proposed method can calculate the similarity of short text snippets more accurately than other methods including the pure TF-IDF measure.     

Simple procedures of choice in multicriteria problems without precise information about the alternatives’ values

The additive model of multiattribute value theory is widely used in multicriteria choice problems. But often it is not easy to obtain precise values for the scaling weights or the alternatives’ value in each function. Several decision rules which require weaker information, such as ordinal information, have been proposed to select an alternative under these circumstances. We propose new decision rules and test them using Monte-Carlo simulation, considering that there is ordinal information both on the scaling weights and on the alternatives’ values. Results show the new rules constitute a good approximation. We provide guidelines about how to use these rules in a context of selecting a subset of the most promising alternatives, considering the contradictory objectives of keeping a low number of alternatives yet not excluding the best one.     

Building a database for product design knowledge retrieval—A case study in robotic design database

In product design process, when dealing with technical problems or initiating a new design, R&D personnel would often turn to technical database to seek inspiration. The building of a database with such documents has not been systematically dealt with. In this paper, several issues on how to build up a product design database are investigated: input source, sampling scheme and quality control. A case study of building a database for robotic design is used to demonstrate the concept. It is an archive of more than 1500 relevant technical papers. A total of 16 graduates are employed as operators in the labeling process and subsequently the hypothesis tests are utilized to process the labeling results. To ensure this database quality, the labeling consistency of each operator and the understanding of each category are tested. With the use of statistical methods, this work proposes a feasible and practical way to create such a database for product design.     

无源二线制智能数字显示表的设计与实现

为了解决LCD在黑暗环境下无法显示的问题,设计并开发了无源二线制智能数字显示表。该无源二线制智能数字显示表采用TI公司生产的MSP430FE427单片机进行控制,详细介绍了其工作原理和实现技术。该仪表能够在没有表头以及外接直流电源的情况下,通过显示模块对二线制传感器检测到的工业参数进行显示;具有精度高、配置灵活、稳定性好等特点,适合用作工业现场的显示单元。     

2009多国仪器仪表展览会流量仪表评估

简要介绍了2009年多国仪器仪表展览会(MICONEX2009)上流量仪表参展商概况、12大类参展流量仪表所占比例,并分析评述了展品及其亮点,如新流量测最原理的激光流量计,向小流量低流速方向延伸的超声流量计、超声热黾表和超声水表,能测量液体的MEMS(微机电系统)制的热式流量计,可代替机械式的MEMS家用/商用燃气表,高阶椭圆齿轮流量计等.     

An improvement on the digital redesign method using fuzzy PWM controller

In this paper, a new digital redesign composed of pulse width modulator (PWM) is proposed. The proposed PWM combines fuzzy logic with genetic algorithm (GA) to tune the parameter of the proposed controller such that the output response of hybrid system closely matches the one of original continuous system. Finally, an illustrated example is proposed to show the proposed method is superior to the existing one.