非接触式电容压力传感器敏感元件的设计及性能分析

将中心岛膜结构的压力敏感膜用在非接触式电容式压力传感器中,解决了平膜结构带来的各点挠度不同、非线性和需要后续补偿电路的问题.通过对材料为多晶硅的中心岛膜进行结构优化设计和挠度、应力等力学性能分析.计算了在不同外加压力条件下压力敏感膜的电容数值、灵敏度和线性度.根据优化设计,外加压力在0.2～1.4× lO.Pa间变化时,电容值在0.0251～0.0281 pF间变化;通过分析两种结构敏感膜在Xy面内同一位置与中心挠度差的变化率,中心岛膜结构的变化率为49.4%低于平膜结构1.7%.因而中心岛膜结构比平膜结构有更好的灵敏度和线性.     

硅压力传感器的灵敏度和非线性分析

灵敏度和非线性是表征硅压阻式压力传感器性能的两个最重要参数,这是压力传感器的设计目标.最初出现的硅压阻式压力传感器都采用圆形均厚膜设计,但由于膜片本身     

微压传感器膜片的设计与关键工艺

<正> 我们采用各向异性腐蚀技术制造硅杯,因此该工艺的要求使得我们不能采用常规力敏元件的圆形膜片,而必须采用正方形或矩形膜片。 对于承受压力p、边长a、膜片厚度h的周边固定的正方形膜片,用小挠度线性理论运     

高精度无油封压力传感器设计

设计了一种新的传感器封装方法。该方法采用双膜片结构,无油封装。压力膜片为硅-蓝宝石材料,通过硅的压阻效应,利用下膜片实现压力传递,上膜片的惠斯登电桥将感受的压力转换为电压信号。经过温度补偿,使热漂移信号大幅度降低。试验结果表明:在常温条件下,传感器准确度为0.14%FS。在-55~200℃范围内,热零点漂移为0.48×10-3%FS/℃,热灵敏度漂移为0.61×10-3%FS/℃。     

多路硅压阻式压力传感器温度补偿系统的设计与实现

基于MAX1457实现了一种多路硅压阻式压力传感器温度补偿系统.MAX1457是一种专用传感器信号调理芯片.此芯片集成化程度较高,可以补偿硅压阻式压力传感器的温度误差和非线性误差.经调理后的综合误差不超过0.1%.在分析该芯片补偿原理的基础上,设计并实现了一种多路补偿系统.     

微型硅压阻式压力传感器研制

结合多晶硅材料的压力敏感特性,通过在硅膜片上沉淀多晶硅压敏电阻及精密的微型化封装工艺,设计了微型硅压阻式土压力和孔隙水压力传感器.传感器通过将硅膜片在压力下的电阻值变化转换为电信号输出,通过标定实验得出:传感器的零点输出小,动态频响高,线性拟合度高,且适用于监测精度要求高的实际工程及受尺寸限制的室内模型试验.     

MPM281型高稳定隔离压阻式OEM压力敏感文件

MPM281系列压阻式OEM产品是一种带隔离、并经过精密补偿的高稳定性硅压阻式压力测量元件。其中硅压阻式敏感元件采用具有专利技术的高稳定性扩散硅元件,外壳采用外径Ф19mm的316L全不锈钢结构进行封装。被测压力经过316L隔离膜片和内部介质传递到硅压阻式敏感元件上,实现了压力到电信号的精确转换。     

一种大量程压力传感器的结构优化设计与仿真分析

设计了一种大量程硅压阻式压力传感器,通过理论模型分析优化传感器结构尺寸,保证薄膜的线性变化和抗过载能力;并通过有限元建模分析可动薄膜位移及应力随压力变化关系,对结构进行优化设计;同时用有限元仿真验证理论分析的正确性.通过理论与仿真优化分析,提出了采用C型膜片一体化硅压阻式压力传感器结构,可动薄膜选用方膜边长为1000μm,厚度为50μm,实现0~2 MPa的压力测量.     

厚膜压力传感器

<正> 在柔性塑料膜上印刷厚膜元件可以制作廉价微型压力传感器。对敏感膜片的两种动作方式进行了研究。第一种方式是将碳聚合物电阻印刷在膜片上,电阻值根据压阻效应而发生变化。第二种方式是将一块导电板印刷到膜片上,构成电容器的一     

扩散硅压力传感器硅膜片形状设计

目前,国内生产的扩散硅压力传感器的硅膜片大多数为圆形膜片。然而,同圆形膜片相比,方形和长方形膜片不仅具有更高的灵敏度,而且给膜片的加工制造带来了方便。下面具体分析三种形状膜片在均布压力作用下其最大应力分布。 1.圆形膜片在均布压力作用下,圆形硅膜片弹性曲面所满足的微分方程为 l/r d/(dr){rd/(dr)[l/r d/(dr)(r(dω)/(dr))]}=q/D (1)式中,ω为膜片挠度;q为膜片承受的均布压力;D为膜片的弯曲刚度,D=Eh～3/12(1-μ～2);h为膜片的厚度;E为膜片材料的杨氏模量;μ为材料的泊桑比。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.