采用双自由度PI速度控制器的PMSM矢量控制仿真研究

分析了永磁同步电机的数学模型.采用励磁电流id=0的转子磁场定向矢量控制方法,在Matlab/Simykuink环境下构建了永磁同步电机(PMSM)矢量控制仿真模型.针对常规PI控制无法满足当电机转速和负载转矩发生阶跃变化时,电机动态响应曲线中转速超调量小和转速恢复施加短的要求,提出了一种双自由度PI速度控制方法.仿真...     

基于LPV观测器的永磁同步电机反推控制

针对永磁同步电机(Permanent Magnet Synchronous Motor,PMSM)无速度传感器转速跟踪控制精度问题,提出了一种基于线性变参数(Lineeo Parameteo Varying,LPV)转速观测器的永磁同步电机反推控制方法。该方法首先根据PMSM的LPV模型,推导出电机的凸胞形顶点方程;然后利用Lyapunov稳定性理论,获得了基于线性矩阵不等式(Lineeo Matrix Inequality,LMI)的观测器设计方法,构造了PMSM的LPV观测器,实现对电机转速及定子交轴电流的重构;最后运用反推控制策略,设计电机闭环系统控制器,实现对电机转速的高精度跟踪控制。仿真结果表明,该方法相较与传统PI矢量控制,跟踪精度高、响应快、抗负载扰动强,对实现PMSM的无速度传感器高精度转速跟踪控制具有重要意义。     

基于重复控制的位置伺服系统

提出了一种控制交流伺服系统的新方法。在永磁同步电机矢量控制的基础上,利用重复控制策略对位置伺服系统进行了控制。根据重复控制理论设计重复控制器,使系统响应输出跟踪周期性输入的参考信号,从而达到跟踪控制的目的。介绍了重复控制的原理、算法以及永磁同步电机数学模型的建立,并给出了重复控制器设计的思路。最后,在输入为周期性位置给定的前提下,进行了仿真实验。仿真结果表明,整个控制系统设计简单、可行、有效。     

基于EKF和SMC的永磁同步电机无传感器矢量控制

采用扩展卡尔曼滤波(EKF)算法估计永磁同步电机(PMSM)转速和转子位置,构成转速、电流双闭环的无传感器矢量控制系统.针对扩展卡尔曼滤波为有偏估计、对模型误差鲁棒性差等问题,提出了基于指数趋近律的滑模转速控制器.为提高转速环抗负载转矩扰动能力,设计负载转矩观测器并将观测结果引入到电流控制器的输入端,作为速度控制器前馈补偿的控制输入.仿真实验结果表明,与传统采用PI(proportional-integral)转速控制器的系统相比,文中所提控制策略具有转速跟踪误差小、响应快、无超调、抗负载扰动能力强等优点.     

异步电机矢量控制系统的设计及仿真研究

研究异步电机控制系统优化问题,系统要求稳定性和抗干扰性能。传统的矢量控制中速度调节器和电流调节器采用PI调节器,依据PI调节器特性,在控制过程中速度响应会出现超调。为了解决上述问题,提出了一种异步电机矢量控制中速度调节器的设计方法,以抑止异步电机矢量控制中速度响应的超调和增强抗扰性为目的。异步电机矢量控制采用转子磁场定向实现解耦,并采用速度环、电流环双环控制方法,根据内模控制原理,设计用一种速度调节器,取代常规的PI调节,成功解决了转速的超调和负载扰动对电机转速的影响。仿真结果表明,提高了响应特性,为优化设计提供了参考。     

异步电机模糊调速矢量控制系统仿真研究

依据异步电机矢量控制原理,空间电压矢量脉宽调制理论（SVPWM）以及模糊控制原理,在Matlab/Simulink下建立了异步电机矢量控制的仿真模型。仿真结果表明,采用该系统对三相异步电机进行控制,具有转矩波动小,转速响应快,超调量小等特点,运行性能良好。     

SiC器件在高速永磁电机转速跟踪控制中的应用研究北大核心CSCD

针对高速永磁同步电机(HSPMSM)的电感值小、基波频率高等特点,以及Si基IGBT开关速度和电压等级限制而引起的电机运行过程中定子电流谐波含量高、发热严重和响应延迟大的问题,研究SiC金属氧化物半导体场效应晶体管(MOSFET)在HSPMSM转速跟踪控制中的应用。通过双脉冲测试电路分析了SiC和Si器件的开关特性,结果表明SiC MOSFET具有更快的开关速度和更低的开关损耗。基于Simulink/PSpice联合仿真,搭建了HSPMSM矢量控制仿真模型。仿真结果表明,采用SiC器件的逆变器能加快电机转速响应速度,减少电流高次谐波,提高输出稳定性,从而提高转速跟踪性能。     

基于模糊控制的直流无刷伺服控制系统

主要研究采用模糊算法设计全数字化微机控制直流无刷伺服系统. 分析了模糊控制器在伺服系统中稳态误差、调节时间和响应时间方面的性能. 用Matlab语言仿真了模糊控制的响应, 并且提出了PI控制加模糊控制的算法, 采用DSP数字信号处理器实现伺服控制.     

智能观测器在伺服系统控制中的应用

研究优化伺服控制系统策略,永磁同步电动机( PMSM)的伺服系统优化,可改善电动机系统的稳定性和响应特性.通过提高伺服系统定位精度和抗干扰能力,有效保证机器运行效率.针对传统有速度传感器矢量控制增加了系统复杂度和成本的问题,为优化伺服系统控制结构,提出了一种采用神经网络观测器的伺服系统无速度传感器矢量控制策略.系统中不需要安装传感器来检测PMSM转子位置/速度信号,而是利用神经网络观测器从电机反电动势信号中估算转子位置/速度,从而优化了系统整体结构,减小了系统复杂度.通过对PMSM的伺服系统无速度传感器矢量控制系统的建模与仿真测试,结果表明,所设计的神经网络观测器能够准确估算转子位置/速度,控制系统能够精确跟踪给定转速指令,改进了伺服系统优化控制问题,为实际应用提供了参考.     

基于Laguerre函数的BLDCM转速预测控制器

针对无刷直流电机(Brushless DC Motor,BLDCM)模型参数时变的特性,为解决不同工况下的转速跟踪问题,将Laguerre函数引入控制器设计中,提出了一种新型的广义预测控制算法。该算法通过对控制量的参数化设计,减少了计算量,使得系统响应加快;通过修改PI型性能指标,抑制了超调,提高了系统稳定性。仿真结果表明,相比传统广义预测控制(Generalized Predictive Control,GPC)算法,用该算法设计的转速控制器对跟踪指令响应更快,抗干扰能力强且对参数不确定性具有较强的鲁棒性。     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.