采用ELVIS的自动控制原理实验辅助系统

本文主要介绍ELVIS在理工科院校控制课程教学中的应用,探讨以虚拟仪器为核心的数据采集系统及其实现信号检测技术的设计方案。利用ELVIS实验板及其自带的函数发生器、数字万用表、示波器等元件,观察到二阶系统的阶跃响应。本实验中,学生自己搭建二阶系统,从响应图上可以更好的理解它的动态特性。实验效果表明,ELVIS平台比传统实验教学装置更具有创新性、实践性,充分调动了学生对实验内容的创造性。     

基于ARM的电话机在家校通系统中的应用

本文介绍了一种基于ARM的嵌入式平台来实现教师、家长与学生的三方信息互动与交流,利用PhilipsLPC2292丰富的外围资源,将射频IC卡、GSM移动公话和短信息通知等有机地结合起来,架构于中国移动先进的网络平台,为各地中小学学生、家长、教师之间提供一种全新的交流方式,更好地推进学生的素质教育,给出了关键电路具体的硬件原理图以及设计要点,并针对具体电话机程序设计中出现的难点提出了简单可行的方法,实践证明该系统具有良好的稳定性和实用性。     

A method for plotting the complementary root locus using the root-locus (positive gain) rules

The root-locus method is a well-known and commonly used tool in control system analysis and design. It is an important topic in introductory undergraduate engineering control disciplines. Although complementary root locus (plant with negative gain) is not as common as root locus (plant with positive gain) and in many introductory textbooks for control systems is not presented, it has been shown a valuable tool in control system design. This paper shows that complementary root locus can be plotted using only the well-known construction rules to plot root locus. It can offer for the students a better comprehension on this subject. These results present a procedure to avoid problems that appear in root-locus plots for plants with the same number of poles and zeros.     

试论加强专业外语教学与提高高校整体教学水平及科研水平的关系

本文对电力系统及其自动化专业的专业外语教学方式、教材的选用等进行了一些初步探讨,并提出加强专业外语教学不但对培养高素质的专业人才,而且对提高高校整体教学水平,科研水平及加强学生思想工作都有不可忽视的作用。     

电路课程网上考试自测系统的开发与实现

开发了一种基于ASP脚本运行环境和Access数据库技术的电路课程网上考试自测系统,提出了一种制定试卷的方法,使管理员和用户可以根据实际情况分别在考试和自测模式下合理选择试卷的范围和难易程度,管理员可以对用户的答题情况进行统计。实际应用表明,既可以使学生不受时间地点的限制进行自我检测,也可以进行统一时间和地点的电路上机考试,是《基本电路理论》国家级精品课程教学的有效辅助工具。     

Complementary root locus revisited

In this paper, a new finding related to the well-known root locus method that is covered in the introductory control systems books is presented, It is shown that some of the complementary root locus rules and properties are not valid for systems with loop transfer functions that are not strictly proper. New definitions for root locus branches have been presented which divide them into branches passing through infinity and branches ending at or starting from infinity. New formulations for calculating the number of branches passing through the infinity point of intersection of the asymptotes on the real axis, and angles of these asymptotes with the real axis have been introduced. It has been shown this type of system with the order of n will have at least one and at most n branches which will pass through infinity. The realization and stability of these systems have been investigated, and their gain plots have been presented. The new finding can be used by educators to complement their lecture materials of the root locus method. By using problems similar to examples presented in the paper, analytical understanding of the students in a classical control systems course can be tested     

A microcomputer-microprocessor-based DC motor speed controller forundergraduate electric machinery laboratory

A microcomputer-microprocessor-based control system is described for speed control of a 7.5 hp separately excited DC motor in the undergraduate electric machinery laboratory at Montana State University. The system uses a Hewlett-Packard (HP) 3497A data acquisition system and a HP/85B microcomputer in conjunction with a Z80 microprocessor. It is used by students to obtain the characteristic of the motor and control its speed under various load conditions. Increased efficiency has been observed in computerized data collection as compared with the traditional method of data collection using analog instrumentation. The control strategy is such that students at the junior level, with limited background in control theory and electronics, can understand its operation. Some experimental results are presented, laboratory experiences are reported, and student responses are evaluated. Additional experiments for the electrical machinery laboratory are also proposed     

具有身分识别功能的高校公寓电能计量系统

介绍了一种以STR730FZ2为核心的具有身识别功能的电能监控系统。系统采用非接触式射频卡方式进行学生用户的身份识别,身份认证后,给相应的用户供电,同时利用传感元器件进行电量采集,记录该用户用电数据,实现了按照个人的使用量收费,解决了均分的弊端。此外,该系统带有CAN总线接口,便于在楼内组建CAN总线网络。     

Development of a Self-Balancing Human Transportation Vehicle for the Teaching of Feedback Control

Control systems education often needs to design interesting hands-on exercises that keep students interested in the control theory presented in lectures. These exercises include system modeling, system analyses, controller syntheses, implementation, experimentation, and performance evaluation of a control system. This paper presents an interesting pedagogical tool, a self-balancing human transportation vehicle (HTV), for the teaching of feedback control concepts in undergraduate electrical, mechatronic, and mechanical engineering environments. Such a pedagogical tool can be easily and inexpensively constructed using low-tech commercial components and feedback control approaches. The effectiveness and performance of the proposed HTV system are examined by conducting several experiments on three different terrains. An education process, together with a pedagogical method, is presented to show how the developed HTV can be incorporated into the laboratory course. To increase students' hands-on experience and keep them interested in learning feedback control, this study also investigated how the enrolled students responded to this new pedagogical tool. This education method along with the HTV system is shown to be significantly effective in helping students to understand feedback control theory and practices, and also to result in more motivated and active learning.      

A basic course in network analysis. I. Content, results,instruction

An introductory course to electric network analysis is described. Both time domain analysis (differential equations, impulse response and convolution integral) and frequency domain analysis (harmonic eigenfunctions and system transfer function) are covered by this course. It is intended that students see these techniques within a global framework. This overview must enable the student to make a motivated choice for one of the methods in problems he has to solve. The passing rates of the course are quite poor. Students show a lack of insight. The presentation of the subject matter, the tutoring of students' exercises and the effort of students in connection with the examination system are discussed. A structural scheme of the subject matter, containing the methods of the course in their relations, is presented. It is concluded that the problems students have to solve as exercises require further analysis     

Using Web-Based Teaching Interventions in Computer Science Courses

An open-source management system of Web-based teaching interventions is presented that can be used in general for science curriculum courses and especially for computer science courses. The proposed solution is called System of Teaching Intelligent Interventions (STII) and facilitates the authoring, deployment, and evaluation of Web-based metaphors. This paper discusses the use of metaphors for assisting students to comprehend the substance of cognitive concepts and their basic background. STII has been applied in a particular educational scenario during the learning process of 228 students attending the course ldquocomputer applications.rdquo The presentation of results from a pilot evaluation of two metaphors demonstrates the usefulness of the system. The evaluation focuses on the impact of the two metaphors on student learning, and on detecting potential correlations between metaphors and students' groups. STII evaluation conclusions strongly support that multimedia metaphors can be used as an alternative instructional tool to assist students in confronting their cognitive constraints and developing functional understanding of curriculum courses.     

ELVIS在实验教学中的应用

本文主要介绍ELVIS在理工科院校信息类专业实验教学中的应用,探讨以虚拟仪器为核心的数据采集系统及其实现信号检测技术的设计方案.实验效果表明,ELVIS平台比传统实验教学装置更具创新性、实践性,充分调动了学生对实验内容的创造性.     

A Pedagogical Software for the Analysis of Loudspeaker Systems

In this paper, a pedagogical software for the design and analysis of loudspeaker systems is presented, with emphasis on training students in the interaction between system parameters. Loudspeakers are complex electromechanical system, whose behavior is neither intuitive nor easy to understand by inexperienced students. Although commercial simulation software provides computation of the equations governing loudspeaker systems, they are mainly focused on the final product and are intended for experienced audio engineers. The proposed software was intentionally designed for education and training purposes. This software allows students to investigate loudspeaker systems that involve complex interactions by illustrating their effects in real time, both in a graphical interface and in numeric values. Unlike other academic simulation tools in the technical literature, students can modify the system parameters, both graphically and numerically, and observe their impact on the loudspeaker responses: pressure, diaphragm behavior, and electrical impedance. Results obtained during two academic semesters showed educational improvement by comparing the outcomes generated by a commercial software and by the designed tool. Students reported very positive attitudes toward this experience and perceived their interaction with the simulation as being generally effective in improving their skills in dealing with loudspeaker system interaction.      

实用的可视化电力系统软件的开发与应用

随着电力系统规模的不断扩大．运用手算方法解决电力系统计算已不可能。传统的编程技术大多是基于文本操作界面的，其计算复杂且结果不直观。为此利用MATLAB与Visual C 计算机技术开发了电力系统的可视化软件。它包括电力系统短路电流计算、潮流计算、稳定分析计算等电力系统常用的13个程序．具有较强的交互性、可视性和可开发性．具有强大的矩阵处理功能和绘图功能。此软件已应用于高等院校的教学中．通过计算机软件对电力系统的模拟，加深了学生对课程内容的理解．提高了学生的计算机应用能力．是有效的计算机辅助教学手段。此软件也可用于电力系统相关部门、在职人员培训及科研人员科技开发工作中。     

An automated system for frequency response analysis with application to an undergraduate laboratory of electrical machines

This paper describes a LabVIEW-based automated system to carry out frequency response tests in electrical machines. The system is being used by undergraduate students in the laboratory of electrical machines, where they can experiment with the application of frequency response analysis and the characterization of mathematical models. An advantage of the system is its friendly user interface to a laboratory experiment. The system avoids the risky utilization of oscilloscopes for data acquisition and shortens the time taken to analyze the measured data. The Automated System for Frequency Analysis (ASFFA) can carry out tests within a bandwidth of 0.001-900 Hz. In addition, the ASFFA can estimate the transfer function parameters based on one- or two-port network theory. Design details of the interface, system structure, frequency response tests, electrical machine modeling, and signal processing are presented. Finally, ASFFA is applied to synchronous, induction, and direct-current machines.     

A study of the relationship between students' learning styles andinstructors' lecture styles

The Myer-Briggs type indicator (MBTI) has been used by previous researchers as an indicator of the learning-style preferences of engineering students in problem-solving courses. In particular, the sensing/intuitive (S/I) scale separates intuitive students with a preference for abstract, global, and theoretical approaches from so-called sensing students, with their preference for the practical, factual, and specific approach. An experiment is described in which two teaching presentations were designed (one intended to appeal to sensing students and the other intended to appeal to intuitive students) and presented to two similar heterogeneous groups of engineering students. The interactions between student-learning style, teaching-presentation mode, and student performance are explored. It is concluded from these results that the S/I dimension of the MBTI can affect the teaching and learning of technical material     

Development of a real time energy monitoring platform

This study introduces development of a user-friendly and quite effectual energy monitoring system which has been installed in Electrical Education Department of Gazi University in Turkey and in use since November 2007. The system developed monitors data in real time using a powerful energy analyzer which is capable of measuring many parameters of energy consumed in the building. The real time data measured by the power analyzer are transferred to a host computer via RS485 serial communication protocol and then collected in a database continuously. Thus, parameters of energy measured are successfully followed, archived, and presented as graphical forms.The monitoring system presented in the study integrates to quite visual and quite user friendly interface with powerful and flexible hardware. Therefore, several functions can be performed easily and safely by simple actions. On the other hand, the system presented in our paper is developed in a university, so it can be used by students to learn energy systems and parameters.     

An innovative DSP-based teaching module for electrical machinedrives

An innovative digital signal processor (DSP)-based induction motor drive system featuring real-time generation of space vector modulated (SVM) waveforms, on-line speed and current acquisitions, programmable soft-start, dynamic braking, and live animation on the basics of drive operations has been developed for teaching and training purposes. Front-ended by the ubiquitous PC that hosts a TMS320C30 module board, the proposed drive system represents a fresh departure from a typical machine drive in a conventional teaching laboratory in terms of its high user-interactivity, flexibility, and fully digitized approach. It has been shown that students using this system can devote their time to fruitful discussions and in-depth experimentations rather than repetitive manual measurements of the motor's voltage and current reminiscent of typical machine laboratory procedures. Selected experimental results highlighting the salient features of the system are presented     

Automated system for measuring electrical three-phase powercomponents

This paper describes an automated system, using the software LabVIEW and an experimental setup including a digital oscilloscope equipped with general purpose interface bus (GPIB) interface, to measure the instantaneous and average power components of generic three-phase electrical systems. The system is being used as an academic laboratory tool for teaching concepts on generic three-phase electrical power systems to third-year electrical engineering students. The method is based on a generalized instantaneous power theory and can be applied to balanced or unbalanced three-phase power systems feeding linear or nonlinear loads. Details of the methodology, comprising acquisition, and signal processing are presented. Examples of three-phase balanced and unbalanced power system measurements are displayed