基于单片机的恒温连续可调型温控系统

提出了一种基于单片机的温控系统软件和硬件的设计方案.本设计采用8位单片机和16位A/D变换器相组合构成温度采集系统进一步提高系统的性价比.采用数字PID控制使温控精度在300-500℃范围内达到1℃,并可实现温度设定值的连续可调.采用铂电阻温度测量电路,并利用软件对测量精度进行自校准;通过电压前馈控制减少电网干扰.设计中还加入了光电隔离措施及过热自动保护和报警功能,增强了系统的安全性能.     

全光纤电流互感器中的TEC温控模块电路设计

在全光纤电子式互感器采集系统中,针对半导体激光器(LD)对温度稳定性的特殊要求,设计了基于ADI公司热电制冷控制芯片ADN8834的自适应温度控制电路。详细介绍了半导体激光器温度控制模块的系统及工作原理,并用仿真软件对电路的稳定性进行了仿真分析。该控制电路采用闭环负反馈结构,利用温度测量输出与给定量之间出现的偏差,通过PID补偿网络形成负反馈,使LD最终稳定在设定温度。通过工程实践,给出了优化PID外围阻容参数的方法,以实现最优的温度控制响应时间和最大振荡幅度的最佳值。经试验验证,该温控电路能够使LD温度在1 s内稳定在设定温度。在-25～+55℃温度范围内,温度控制精度为0.01℃,稳定度可达0.04℃。该温控电路为模块化设计,易于集成,工作范围宽且成本低廉,完全能够满足现场应用需要。     

一种关于挠性加速度计温度控制系统设计方法

为了提高石英挠性加速度计的零偏稳定性指标,确保惯性导航系统定位定向精度,需要石英挠性加速度计长期工作在稳定的环境温度范围内,相应的温度控制系统设计技术尤为关键;针对某高精度惯性导航系统对温度控制精度指标的实际需求,首先设计了以DSP为核心控制器的温度控制硬件电路;同时以加速度计组件为控制对象,建立温控模型,采用PWM波控制策略及增量式PID控制算法,利用MATLAB仿真工具获得较优的控制参数;在DSP中开发了温度控制程序,并进行参数整定、指标测试,最终使加速度计工作环境温度稳定在55±0.2 ℃范围内;通过实际应用验证表明,该方法针对石英挠性加速度计工程应用特点,实现的温度控制精度高,稳定性好,能够为惯性导航系统的高精度使用奠定基础。     

基于ADN8831的高精度光源驱动控制设计

针对光纤陀螺光源驱动控制特点,设计了一种新型高精度超辐射发光二极管(SLD)光源驱动控制系统.恒流源输出电流稳定且光源保护措施可靠,温控系统以高性能TEC控制器ADN8831为核心,功耗低,体积小且集成度高.测试结果表明:该系统性能优良,操作方便,恒流精度可达0.01%,温控精度优于0.005℃,光源输出光功率在-40～+70℃范围内比较稳定,能够满足光纤陀螺系统对光源控制精度和稳定性的要求.     

小型精密恒温槽

简述了由热电致冷器组成的小型精密恒温槽的结构及控制线路设计.该恒温槽的工作温度可在0～30℃之间任意设定,当环境温度在 -10～ 40℃之间变化时,温度控制精度可达设定温度±0.5℃以内,温度稳定性优于0.3℃.     

基于模糊自组织模式的智能控制加温系统

论文介绍一种新型的智能控制加温系统。该系统硬件上以MCS-51系列STC89C52芯片为核心,利用Pt100电阻结合桥式电路和仪用放大电路对温度进行高精度感知作为系统输入信息,加温电路为多分枝自组织电路;通过构建模糊自组织模式的控制算法,系统将温度感知信息经智能控制算法分析处理后,选择加温电路的构成方式,实现对物体加温精度和速度优化的智能控制。研制系统的实际测试结果表明,这样的系统可获得高的温度控制精度,也能优化加热速度。     

半导体激光器双闭环温度控制系统

为了提高半导体激光器输出波长的稳定性,研制了一套双闭环温度控制系统。其中,外环温控以集成化模块MTD1020T为核心,通过优化数字式PID参数,最大可驱动20 W的热电制冷器(TEC),可实现±0.5℃的温控精度;内环温控以控制芯片LTC1923为核心,通过增加差分放大环节及设置PI环节,可实现±0.01℃的温控精度。实验结果表明,双闭环温控系统可将外环快速、大功率温控与内环高精度温控相结合,能够在20 s内实现±10℃的温度调节,4 h内其温控准确度控制在±0.02℃内。该温控系统具有可控范围宽、响应迅速、集成度高等优点,可应用于飞行器气体浓度探测等便携式气体探测领域。     

模型函数结合改进PID的温控系统设计

为满足在实验室和计量校准应用场合中温控设备对体积轻量化和提高精度的需求,设计一款适用于便携式高精度温控设备的温度控制系统。系统在硬件上基于STM32F407微控制器,采用半导体制冷(热)片调节温度;软件框架基于FreeRtos操作系统,采用简易温度模型函数和改进PID结合的方式设计温控算法。算法可通过简单方法获取简易数学模型函数并与改进PID配合发挥极好的控制效果。经验证,该系统在5℃～50℃范围上连续可调,精度达到0.05℃。相比传统的PID系统,本设计具有响应速度更快、超调量更小等优点,鲁棒性强,具有很高的应用价值。     

面向皮卫星应用的MEMS陀螺温度控制系统设计

设计了一种面向皮卫星应用的MEMS陀螺温度控制系统,其控制原理为基于ADN8831的TEC温度控制。分析了影响温控系统控制精度的各因素,并且通过Steinhart-Hart方程对热敏电阻的R-T特性进行拟合校准后表明,本温控系统的精度达到±0.03℃。将设计的温控系统应用于面向皮卫星的MEMS陀螺温度控制,通过Allan方差分析MEMS陀螺的误差项。通过不同温度下实验得出,当该温控系统存在时,零偏不稳定性和速率随机游走得到了不同程度的改善,验证了温控系统的有效性,满足了皮卫星体积小、功耗低的要求。     

一种大功率TEC温控系统的设计

小功率半导体激光器常采用TEC片进行温度控制,其中,TEC片工作电压为5V,工作电流低于4A的应用已经有了几种成熟的芯片方案,而更高电压和电流的TEC温控需要自行设计控制系统。设计了一种基于AVR单片机ATmega128,适用于较大功率TEC片的温控系统,主要技术指标包括：TEC片工作电压范围6V-24V,峰值电流≤20A,控温范围：0-70℃,控温精度±0.05℃。使用负温度系数热敏电阻采集温度,包含温度信息的电压值转化为数字量输入单片机,单片机根据位置式PID控制算法的计算结果输出控制信号,驱动由两片BTN7971B构成的H桥电路,H桥输出电压提供给TEC片。对硬件和软件的实现方法进行了详细分析,重视控温精度、系统的可靠性设计。经过实际测试,可实现前述技术指标,能满足较大功率半导体激光器的控温要求。     

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.