冗余式高压直流无刷电机控制系统设计

在冗余式高压直流无刷电机基本结构的基础上,研究了冗余式高压直流无刷电机的控制策略,设计了一套基于DSP的冗余式高压直流无刷电机控制系统;该系统主要分为控制电路、隔离电路、驱动电路、主功率电路、故障检测与保护电路和系统供电电源模块等;系统采用专用电机控制集成芯片TMS320F2812为控制核心,实现了总线控制、电机余度工作模式的切换、正/反转运行、故障检测与保护等功能;系统采用转速闭环控制策略,实验结果表明系统动态响应快,稳速精度高,并在两个余度同时工作时实现了电流的均衡.     

基于DSP平台高性能控制系统与方法研究

基于DSP平台的高性能控制系统由DSP主控板,电机驱动电路板和电源板三个主要部分组成.文中详细说明了系统结构图,叙述了数字输入数字输出电路的组成,给出了模拟输入电路设计原理以及模拟量输入通道控制电路图.在基于DSP的控制系统设计中考虑了故障处理电路.故障处理电路包括过流保护电路和三相不平衡保护电路.阐述了光电编码器接口电路设计思想和接口电路图.实现了对于给定转速的电机运行状态显示.解决了获取转速信息,通过A／D检测电压电流,实现控制算法等关键问题.     

基于F28335的小型化无刷直流电机伺服控制器的开发

介绍了一种小型化高性能无刷直流电机伺服控制器的软硬件设计及实现.硬件上采用TMS320F28335型DSP为核心处理器,设计了三相全控桥式功率驱动电路和完成欠压、过流检测等检测保护电路.能通过CAN总线实现与上位机的高速通信并进行实时数据交换,应用PID算法实现电机的位置闭环和转速闭环数字调节.实验结果表明控制器基本满足200W以内的中小型无刷直流电机驱动控制需求.     

工业机器人交流伺服驱动系统设计

针对工业机器人系统应用和高性能国产化伺服系统开发,研究了基于DSP控制器的全数字交流伺服控制系统的设计与实现。实现了基于DSP控制器TMS320F28335的交流伺服控制系统的电机控制电路。论述了整流电路、功率驱动电路、信号采集电路及保护电路等模块的设计原理。设计实现了各个闭环实时控制算法的DSP控制器软件模块。运动控制采用了面向插补控制的位置环给定端控制。     

基于DSP的交流电机伺服控制器设计

对基于DSP交流异步电机伺服控制系统进行硬件设计,介绍了双闭环伺服电机硬件电路的设计,并主要介绍DSP外围电路的设计及器件选型,包括整流逆变电路、能耗制动电路、电流检测电路、光电编码电路、温度检测电路以及电流保护电路.通过温度和电流检测电路对电机的运行状态进行实时保护;通过光电编码电路可以对增量式光电编码器信号进行信号变换;DSP对光电编码器的信号进行解码,并通过换算关系进行电机转速和位置的计算.本系统在基于电流环、速度环检测的基础上对交流电机进行精确的转速控制.     

一种新型矿用高压保护器综合测试台设计

设计了一种新型矿用高压保护器综合测试台,介绍了该测试台的总体结构及软、硬件设计方案。该测试台以S7-300系列PLC为控制器,可以产生短路、过流、欠压、过压、零序过压、零序过流等故障信号,并将故障信息、试验项目及相关硬件运行状态显示在上位机监控界面上,从而快速检测高压保护器的性能。以ZBT-11高压保护器电流保护功能测试为例进行了测试台功能检测,结果表明该测试台能够快速、准确地检测出高压保护器故障。实际应用验证了该测试台效果良好。     

医用仪器绝缘性检测的直流高压电源的设计

长期以来,由于医用设备绝缘性故障造成的医疗事故屡见不鲜。然而,国内直流高压电源技术在绝缘检测仪的研究处于空白状态。基于此,设计一种医用仪器绝缘性检测的直流高压电源。本文中的直流高压电源由DC-AC逆变电路、AC-AC升压变压电路、AC-DC倍压整流电路、过压保护电路和反馈调节电路五部分组成。实验表明,此直流高压电源工作稳定,为医用绝缘检测仪的开发提供了参考。     

基于储能Crowbar的直驱风电系统低压穿越控制策略

随着风力发电装机占比的提升,对其安全可靠性要求也越来越高。低压穿越(LVRT)能力是直驱式风力发电系统性能的重要评估指标。针对因为电网故障产生电压跌落、风电系统不脱网稳定运行的要求,提出了一种新的基于电容储能装置的Crowbar卸荷电路实现LVRT的方法。该方法利用滞环控制以及输入信号互锁控制Crowbar电路切入切出,实现了精准控制系统开关元器件,以防止开关频繁动作导致的系统失稳。仿真对比结果表明,该方法能够安全、稳定运行,并能够有效降低系统网侧有功功率的输出,以防止过电压对直流母线侧的冲击。与传统的低压穿越控制策略相比,基于储能的Crowbar方法可以有效地补偿直流母线电压的欠压状态,从而显著提高系统的低电压穿越能力。     

基于DSP的小型直流风扇自动化测试系统

针对目前我国小型直流风扇产品出厂检测设备落后的现状,采用现代微处理器检测与控制技术开发了基于DSP控制器TMS320F2812A的新型直流风扇自动化测试系统。该系统实现了直流风扇的一站式测试,大大提高了测试效率。给出了该系统的设计和实现方法,介绍了其主要硬件电路结构和软件流程。实际应用表明,该系统在性价比、测试速度和可维护性等方面均有明显的优势。     

一种基于TL494芯片的电动车电机控制器

他励直流电动机驱动系统结构简单、性能可靠、成本低,适合在小型电动车上运行,有效的降低了电动汽车的价格,有利于电动汽车的普及。本文在分析电动车用他励直流电机工作原理的基础上,论述电机驱动系统的整体方案,并设计3KW/36V他励有刷直流电机控制器。该控制器主要通过TL494控制,包括36V铅酸蓄电池欠压保护,控制器的过热保护等功能。经实验证实该控制器达到设计指标,工作稳定可靠,满足电动车的各种运行情况,保护功能完善并具有能量回馈等功能。     

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.