带参数辨识的自适应二阶滑模观测器PMSM无传感器矢量控制

针对表贴式永磁同步电机无位置传感器矢量控制系统, 提出一种具有电机参数在线辨识的基于Super-twisting algorithm的自适应二阶滑模观测器.在两相静止坐标系下,将模型参考自适应方法与基于Super-twisting algorithm的二阶滑模方法相结合,实现反电动势的准确估计.采用李亚普诺夫理论证明观测器的稳定性,并由李亚普诺夫稳定性方程推导定子电阻和转子转速的自适应律.在同步旋转坐标系下,采用二阶滑模观测器估计永磁磁链,并将其输入位置跟踪观测器估计转子位置.该算法充分抑制了滑模抖振,同时避免了低通滤波和相位补偿环节的使用,转子位置检测不受定子电阻和永磁磁链变化的影响,具有较强的鲁棒性.仿真结果验证了所提出算法的有效性.     

内置式永磁同步电机无传感器矢量控制方法的研究

本文介绍了一种内置式永磁同步电机无传感器速度控制器.它能够充分的利用电机的转矩转速特性,包括在弱磁区.它是一个基于Luenberger状态和扰动观测器反电动势空间矢量的估计方法.估计得到的转子磁链位置和转速被用于一个最优化的dq轴电机电流轨迹矢量控制方案.最终实验结果证明了解决方案的可行性和性能的可靠性.     

刮板输送机永磁同步电动机无位置传感器控制

传统转子磁链观测器受直流扰动和谐波扰动的影响无法准确估计转子磁链,进而基于转子磁链的永磁同步电动机无位置传感器控制方法无法准确估计转子位置。针对该问题,提出了一种基于三阶广义积分磁链观测器的刮板输送机永磁同步电动机无位置传感器控制策略。通过引入三阶广义积分磁链观测器,能有效抑制高次谐波分量,稳态时可完全消除转子磁链中的直流分量,且对基波的幅值和相位没有任何影响,从而准确估计转子磁链,提高转子位置估计精度。仿真结果验证了该控制策略的正确性和有效性。     

永磁同步电机无位置传感器控制研究

位置传感器会增加电机控制系统的成本,降低系统的可靠性和性能,在无法安装位置传感器的电机调速场合或在恶劣环境中难以应用.论文针对永磁同步电机给出一种转子位置实时估计方法,利用反电势得到的位置特征点对转子位置进行估计,实现了无位置传感器永磁同步电机的空间矢量控制.实验结果表明,本文提出的估计算法可以实时估计转子位置和转速,采取该算法对无位置传感器永磁同步电机进行矢量控制,算法易于实现,实时性好,电机控制系统调速范围广、运行稳定.     

IPMSM有效磁链二阶滑模自适应估计控制

针对传统滑模观测器的动态品质差、抖动大的问题,提出一种基于无位置传感器内置式永磁同步电机控制系统的定子有效磁链二阶滑模自适应磁链观测器。该观测器利用超螺旋算法理论,以静止坐标系下电流误差及电流误差的估计值为状态变量,构造出定子电流误差估计值的二阶滑模自适应观测器,得到准确的有效磁链估计,使得该估计值可在有限时间内快速收敛且具有强鲁棒性;同时利用定子磁链估计值获取电机转子位置信息,实现电机稳态运行。仿真和实验结果表明,在不同负载条件下该观测器具有很强的适应性,且磁链估计值抖动小、精度高,因此所提控制方案可行有效。     

基于速度信息观测的无轴承永磁同步电机悬浮解耦控制

无轴承永磁同步电机以转子位置信息为媒介实现解耦控制,整个算法复杂且依赖速度传感器.本文研究电机无传感器运行及解耦算法简化的方法.首先将传统扩张状态观测算法简化为线性形式.然后将二、三阶线性扩张状态观测器分别加入转矩和悬浮系统电流环和位移环,并定义电角速度与转矩d-q轴电流乘积以及转矩系统q轴磁链与悬浮d-q轴电流乘积为扰动项,利用观测器辨识转速信息及悬浮扰动力.接着对转速信息进行处理、对悬浮扰动力进行补偿从而实现无速度传感器运行并简化悬浮解耦算法.最后通过仿真验证所提控制策略能够实现电机无速度传感器运行,保证额定转速下稳定悬浮.     

基于NESO的永磁同步电机无位置传感器控制

由于使用高分辨率的机械传感器会增加永磁同步电机(PMSM)的体积和成本,降低系统的可靠性,因此在电机控制领域引入了无位置传感器控制技术。根据扩张状态观测器的理论,设计了非线性扩张状态观测器(NESO)来观测PMSM的反电动势,实现对电机转子速度和位置的估计,并通过分区分析和Lyapunov理论分析了观测器的收敛性。最后,通过对观测器的仿真实验,验证了NESO能够对系统的转速和位置实现较好的跟踪,并且具有很好的鲁棒性。     

基于滑模观测器的永磁同步电机矢量控制

本文提供了一种基于滑模观测器的永磁同步电机矢量控制系统的实施方案.设计一滑模观测器,对永磁同步电机的转子位置角和转速进行实时在线估算,实现电机的闭环调速运行.仿真结果表明,本文提出的这种滑模观测器对系统参数摄动、外干扰以及测量噪声具有的极强鲁棒性,有效地改善系统的动、静态运行性能.     

表贴式永磁同步电机无位置传感器控制

位置传感器会增加系统成本和测量噪声,且无法应用在一些恶劣环境.论文在研究表贴式采磁同步电机无位置传感器的控制策略的基础上,提出一种基于反电动势的位置估计方法.利用两相旋转坐标系下电机方程的反电势形式,结合前馈控制,计算出转子位置的偏差角度,再采用锁相环结构对电机的相位和速度进行估计.在电机的低速运行阶段改进锁相环结构,保证速度估计精度,并进一步改善系统动态性能.建立了永磁同步电机的仿真模型,验证了该控制方法的可行性.在STM32F103X(ARM)为主控制器的实验平台上实现了所提出的表贴式永磁同步电机无位置传感器控制方法,实验结果表明该控制方法能够准确估计出电机的转速和转子位置,估计算法简单,系统稳态精度高、响应速度快.     

无速度传感器PMSM混沌运动的非奇异快速终端滑模控制

针对永磁同步电机调速系统中速度传感器存在安装缺陷及在某些特定的参数下电机会呈现混沌特性,提出了无速度传感器永磁同步电机滑模控制混沌抑制方法．在无速度传感器运行的永磁同步电机矢量控制调速系统基本框架下,采用非奇异快速终端滑模控制方法来抑制电机的混沌运动．首先在永磁同步电机的混沌模型基础上通过仿真验证了混沌现象的存在;然后利用扩张状态观测器（ESO）估计转速,构成无速度传感器永磁同步电机矢量控制系统;在此基础上设计了非奇异快速终端滑模控制器,当电机在某些参数条件下呈现混沌现象,即刻通过控制器的切入来抑制永磁同步电机的混沌运动．最后通过仿真验证该方法的有效性,保证电机运行稳定和可靠.     

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.