轴角检测电路在永磁同步电机驱动系统中的应用

设计并实现了基于旋转变压器的永磁同步电机驱动系统。重点介绍了由旋转变压器／数字转换器AD2S90和旋转变压器组成的电机轴角检测电路的设计，详细分析了它与主控芯片的接口电路和它们之间的数据传输方式。实验结果表明，系统设计合理，数字轴角检测电路正确可行。     

基于AD2S1200的旋变接口电路设计及信号处理

应用旋转变压器/数字转换器AD2S1200,将旋转变压器输出的模拟信号转化为数字信号,以便于DSP进行处理。介绍了旋转变压器的基本原理,设计了AD2S1200与旋转变压器及TMS320F2808型DSP的接口电路,并提出了一种容错性较强的位置信号数字处理方法。实验证明,该设计方法精度高,可靠性好,抗干扰能力强,完全能够满足高速电机控制系统的要求。     

基于C8051F064的旋转变压器-数字转换器

研究一种以C8051F064为核心的旋转变压器-数字转换器,详细论述该系统软、硬件的设计,并介绍一种有效的误差修正方法。该转换器通过旋转变压器输出的两路交流信号和一路基准信号,解算出旋转变压器偏移的角度。实验结果表明,该旋转变压器-数字转换器能够较精确地完成所要求的信号转换。     

电机专用集成电路的应用 五：旋转变压器专用轴角变换器

在模拟系统中,旋转变压器是精确而又可靠的轴位置传感器。但随着数字控制技术的发展,迫切需要数字式位置检测装置,因此,如何将旋转变压器输出的模拟量转换成数字量,便成为现代轴角变换器的主要任务了。正余弦旋转变压器专用轴角变换器(RDC)在多年前就已出现,近来采用高新技术开发的新一代单片RDC相继问世,其价格低、分辨率高、跟踪速度快,已成为用户的优选产品。美国AD公司的AD2S80A便是典型产品之一。     

旋转变压器在数字伺服舵机系统中的应用

设计完成了一个采用旋转变压器检测舵反馈的数字伺服舵机系统,使用一款用于电机控制的SOCG105作为系统的控制核心,介绍了正余弦型旋转变压器的基本原理,设计了旋转变压器与G105的接口电路及相关外围电路,并利用G105内部的旋变解码模块实现舵面角位移的解算.试验证明,该方案简化舵机控制电路的设计,并能够精确地实现舵反馈的测量.     

基于旋转变压器的永磁同步电机驱动技术研究

设计并实现了一种基于旋转变压器的永磁同步电机驱动系统。给出了系统的硬软件设计方案,重点介绍了旋转变压器 数字转换芯片AD2S80A及其相关参数的选择,并设计了它与电机专用芯片DSPTMS320F240的接口电路。实验结果表明,系统设计合理,旋转变压器和AD2S80A组成的数字位置检测电路正确可行。     

基于AU6802的旋转变压器接口电路应用设计

应用数字转换器件AU6802对旋转变压器输出互为正余弦关系的模拟信号进行采样，将其转换成与光电码盘输出一致的数字脉冲信号，以便于各种CPU进行处理。介绍了旋转变压器和AU6802芯片的基本工作原理，研究、设计了旋转变压器与AU6802之间的接口电路，最后应用Muhisim软件对接口电路进行仿真分析。实验表明该接口电路性能稳定，可以使电机在扦、闭环工作方式下运行，能够准确地实现电机位置、速度的检测，实现了光电码盘的功能，具有较高的应用价值。     

单片机三维轴角智能化测量系统

单片机三维轴角智能化测量系统马瑞卿，芦刚，刘昌旭，李钟明，窦满锋（西北工业大学）１引言用旋转变压器实现轴角精密测量需要解决的关键是将多极旋转变压器的模拟量变成数字量。８０年代后期，我国自行研制的１４／１２位ＸＳＺ系列旋转变压器一数字转换器达到世界水平...     

旋转变压器数字转换（R/D）及其工程应用

在介绍旋转变压器数字转换(R/D)工作原理的基础上,分析了其工程设计及应用中遇到的相关问题,给出了解决办法,具有一定的实用意义.     

同步机及旋转变压器二级轴角编码纠错方法

介绍同步机及旋转转变压器二级轴角编码纠错方法。这种方法可适于任何二级数字系统。     

Methods for controlling a linear asynchronous motor

This article describes the case of one of possible method of controlling a linear asynchronous motor (LAM) with a controlled normal component of the force of interaction between an inductor and a reactive bus. It is shown that the normal force in a unilateral linear asynchronous motor can affect significantly the operation of devices and systems on which a motor is installed. This normal force can attract an inductor to a reactive bus or repel it from a reactive bus. For the model of a motor, which is represented by four zones, namely, an inductor, an air gap, a conductive bus, and a steel core of a reactive bus, the analytical expressions for the calculation of the components of a magnetic field in an air gap were obtained. The effect of the longitudinal and transverse edge effects in the considered plane model of a motor is not considered. The expressions for the determination of the specific tangential and normal forces per area unit were found. It is shown that, under a change in the slide from negative to positive values, the tangential force changes similarly to the electromagnetic torque of a conventional asynchronous motor with a rotating rotor. Under a change in the slide, the normal force can attract an inductor to a reactive bus or repel it from a reactive bus. The force of attraction reaches the highest values under a zero slide. The slide under which the normal force is equal to zero is determined only by the pole pitch and the conductivity of material of a reactive bus and provides the operation of a motor at the highest power factor. It is proposed to use the measured normal force value as a parameter for the construction of a traction linear asynchronous motor-control system.     

Negotiating expert status: who gets taken seriously

A lay person may listen puzzled as a specialist in a public hearing discusses a technical point. Similarly, a challenging question from a technically knowledgeable member of the audience may be difficult to fathom. Failure to understand what a speaker discusses-despite one's interest in a topic-can cause frustration, anger and despair. It makes a listener wonder why they are there trying to engage, and why technical specialists persist in such a style of presentation. Breakdowns in communication between technical and nontechnical people are linked to the concept of “expert”. This link involves the process of the “negotiation of expert status”; this refers to the social construction of the role of the “expert” by the participants in a conversation. The term “negotiation” refers to the sometimes subtle and sometimes overtly contentious nature of a debate about who deserves to be listened to as a voice of authority on a particular topic     

水利工程模糊多模式工期-成本-质量均衡优化

针对不确定环境下水利工程建设项目的工期-成本-质量均衡优化问题,采用双指数函数和二次函数分段模拟工程质量和工期之间的关系,构建了水利工程模糊多模式离散工期-成本-质量均衡优化模型。运用微粒群算法对其进行求解,并将优化结果与相关文献进行对比分析,验证了模型的合理性和计算方法的有效性。最后,将该模型应用于水利工程实例,为决策者进行目标计划和控制提供理论依据。     

换热器管壁圆形泄漏口空间辐射声场分布特征数值研究

根据可分离辐射源的声辐射，利用叠加原理和无穷级数迭代求和，建立了换热器管道壁面圆形口非分离泄漏声辐射源的空间声场分布数学模型。计算了圆形口均匀幅度非分离声辐射源的空间声场远场分布，给出了其远场相对声压级和位相的空间分布图案。与方形口均匀可分离辐射源的空间声场分布特征相比，发现两种情况具有相同的空间指向性特征，在较高频率时辐射声场空间分布出现盲区，在x—y平面内声场分布与泄漏口形状无关，但与辐射频率有密切关系。     

单元机组协调系统的非线性内模控制

协调系统的性能直接影响单元机组运行的安全性和经济性。为了克服非线性环节以及能量供需之间关联耦合作用对协调系统控制品质的影响，本文将反馈线性化方法与多变量内模控制结构结合，针对一个通用的非线性协调系统模型，设计出非线性内模协调控制器。文中分析了多变量非线性内模控制结构的鲁棒稳定性及动态性能。在不同负荷下的仿真试验表明，所设计的控制系统具有良好的解耦效果和抗干扰能力。     

Self-regulated self-excited brushless three-phase synchronous generator

For lightweight and compact implementation of a generation set, many attempts have been made by some researchers to develop a brushless self-excited synchronous generator without an ac exciter. A previous paper proposed a novel self-excitation scheme by which the second-space harmonic component of armature mmf is used for exciting the rotor field system. In this excitation scheme the effect of the series excitation characteristic, as well as a self-excited and brushless implementation without an ac exciter is automatically obtained. However, in the case of system configuration of the generator already reported, voltage regulation in the inductive load condition was very large. To remove this problem, this paper presents a new system configuration of the generator with a self-regulating feature that can compensate voltage regulation automatically. The new generator consists of a stator installing two three-phase windings, externally connected to a load and a capacitor bank, respectively, and a rotor with field and harmonic windings. In this paper the system configuration and theoretical concepts of the presented generator are described and detailed experimental investigations with a laboratory machine are also shown.     

A Traffic Accident Recording and Reporting Model at Intersections

In this paper, we suggested a vision-based traffic accident detection algorithm and developed a system for automatically detecting, recording, and reporting traffic accidents at intersections. A system with these properties would be beneficial in determining the cause of accidents and the features of an intersection that impact safety. This model first extracts the vehicles from the video image of the charge-couple-device camera, tracks the moving vehicles (MVs), and extracts features such as the variation rate of the velocity, position, area, and direction of MVs. The model then makes decisions on the traffic accident based on the extracted features. In a field test, the suggested model achieved a correct detection rate (CDR) of 50% and a detection rate of 60%. Considering that a sound-based accident detection system showed a CDR of 1% and a DR of 66.1%, our result is a remarkable achievement     

Velocity probe for hydrocarbon liquid laminar flows using theconvection of the electrical diffuse layer

A probe has been perfected which establishes a relation between the velocity of a laminar flow of a dielectric liquid and the current due to the convection of a part of the electrical diffuse layer. In the first part of the paper, the theoretical diffuse layer appearing on a flat plate and for a liquid at rest is computed. Then, when the liquid is moving the electric charge convected and the potential difference between two points of the plate are obtained. The second part of the paper describes the probe, and a series of experiments performed all along a cross section