实时仿真系统信号复用/解复用算法设计

硬件在回路实时仿真是研究复杂机电系统过程中的一个重要环节,由于仿真通道数量有限,不能满足复杂机电系统大量信号的同步仿真需求。提出一种信号复用/解复用算法,其基本思想是信号复用算法在仿真器的FPGA中实现,将仿真信号复用重组,并在一个仿真周期内通过同组仿真输出通道分批发送;信号解复用算法在接口板卡CPLD中实现,根据解析出的同步时钟信号和寻址信号,将重组信号还原,并发送给被测控制器。仿真结果表明,提出的复用/解复用算法实现了大量的仿真信号通过少量的仿真输出通道与被测控制器同步交互,解决了实时仿真系统中仿真通道不够用的技术难题。     

电力电子系统硬件在回路仿真技术的探讨

介绍了电力电子系统建模技术,对实时仿真平台、开关延迟问题和数值积分方法等硬件在回路仿真关键技术进行了探讨,为电力电子硬件在回路仿真系统的构建提供参考.     

卫星姿态控制系统硬件在回路仿真研究

为了便于卫星自主智能控制技术的研究,该文研究了控制系统硬件在回路仿真技术,分析了实时仿真系统中仿真步长的确定及通讯接口技术的应用。文中详细说明了在MATLAB下采用S—function编写串口驱动模块的方法,还介绍了利用MATLAB／xPC环境下的UDP模块进行数据传输的方法。最后,该文设计了一个基于PC机的三轴稳定卫星姿态控制硬件在回路仿真系统,将反作用飞轮、陀螺等实物接人仿真系统。仿真结果表明实时仿真结果与数学仿真结果基本一致,仿真系统接口设计合理,实时性符合要求。     

基于STC微控制器的DC电机系统设计

本文详细介绍了一种基于单片机的直流电机PWM调速和实时显示功能的设计。本文以STC89C52单片机为核心，通过霍尔传感器实现对直流电机转速的测量，并通过LCD1602进行实时显示。本文分别从硬件部分和软件实现等方面对设计做了详细的阐述。硬件部分通过键盘控制使单片机产生不同占空比的脉冲对电机转速进行控制，将霍尔传感器产生的脉冲信号传入单片机系统，然后单片机系统将信号经过处理送LCD显示。软件部分用C语言进行程序设计，实现对硬件的控制。本文采用模块化设计思想，介绍了PWM调速模块、霍尔传感器模块、LCD显示模块等功能模块。本文设计的直流电机调速系统可以使用按键对直流电机进行智能调速，准确而灵敏，这对生产生活具有重大意义。     

基于FPGA的脉冲量采集模块设计

设计了一种脉冲量采集模块,用于脉冲信号的采集和传输.文中详细阐述了该系统的硬件和软件设计方法来说明模块的实现过程.重点介绍了系统硬件电路设计及其实现,采用FPGA作为中心控制单元,对脉冲信号的幅值、个数、及频率进行采集.测试结果表明,该模块完全满足实际工程需求,具有很高的可靠性,并且已成功运用于某通用测试台项目中.     

基于TMS系列DSP实现LFM信号的实时脉冲压缩

研究了以定点通用型DSP芯片TMS320VC5509为硬件核心的LFM信号实时脉冲压缩技术。在CCS 3.3软件开发平台上实现,采用C语言编程,结合Matlab仿真得到LFM信号和匹配滤波器的系数,在时域实现脉冲压缩算法。为有效抑制副瓣的影响,采用海明窗加权函数对滤波器进行调制。采用单位阶数耗时衡量滤波算法,通过增加滤波模块接口的方法对数据存储更新方式进行优化,并结合FIR滤波器的特性简化了卷积算法。测试表明,系统工作稳定,处理精度和实时性均达到了较高标准,可以满足工程应用的要求。     

基于实时视窗目标的硬件在回路仿真实现方法研究

基于Matlab实时视窗目标的硬件在回路中实时仿真系统开发具有周期短,费用低的特点,并且是硬件在回路中仿真最便捷的实现途径,但是实时视窗目标同硬件设备的通信还存在一定的局限性.提供了一种通过S函数自定义设备驱动程序的方法,这样大大扩展了实时视窗目标外部通信能力.结合实例介绍了基于实时视窗目标硬件在回路中仿真系统的体系结构,并且详细分析了仿真系统中借助S函数自定义设备驱动程序的实现方法.该方法具有一定的通用性,对基于Matlab的硬件在回路的实时仿真系统的实现有借鉴作用.     

机载新型机电管理系统综合检测技术研究

针对现代飞机高集成度机电管理系统的测试与仿真需求,提出一种基于PXI技术的新型机电管理系统综合检测系统设计与实现方案。在该方案中,机电管理系统的所有信号经过信号接口盒后进入到综合检测系统中,通过断点模块连接机电管理系统产品,在断点模块可以对综合检测系统的所有信号进行监控测试、信号验证及分析处理;通过硬线、RS422总线、GJB289A总线、ARINC429总线形式将机电管理系统和机电管理系统综合检测系统相连接。该系统可有效节省硬件资源、准确实现信号级故障隔离,可实现机电管理系统硬件和软件的独立检测并且可实现多台机电管理系统的测试和检验;与传统手动检测相比,可以平均节省60%的检测时间。通过测试和试验,机电管理系统综合检测系统工作稳定、可靠。     

基于编码器的矿用车门行程监测系统研究

本系统用矿用车门开关传动轴带动编码器件滚轮滚动,利用编码器件将电信号转换成一串数字脉冲信号,将数字信号传给MCU处理,通过对脉冲信号的累计计算出矿用车开关门行程,监测就是针对代表矿用车门开关量的脉冲信号,实时监测车门开关行程,经过PCA中断程序和MCU主程序查询,对开关门计数脉冲进行实时记录,在全开、全关两种状态下用信号灯或报警装置提示车门开关极限状态,根据计数脉冲个数计算车门开关进程,实现对矿用车行程的实时监测、实时显示。     

一种开关磁阻电机模数混合式控制系统的设计

本文介绍了一种开关磁阻电机模数混合式控制系统的设计方案。分析了开关磁阻电机的数学模型和工作原理,提出基于定角度电压斩波方式的速度单闭环控制方案,控制回路采用模拟方式实现PI速度调节,反馈回路则采用以80C51为核心的单片机系统进行位置信号与反馈速度之间的转换处理,同时给出相应硬件结构。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.