提出一种无差拍控制与调制策略,实现其电流和中点平衡控制功能.首先阐述无差拍预测控制的工作原理,提出了改进的无差拍有功和无功控制技术.和传统的PI控制器相比,无差拍控制器具有低电流谐波和无参数调节,动态响应快.针对单相三电平逆变器存在中点电位不相等情况,提出了单相三电平变换器空间矢量调制技术.基于空间矢量调制和无差拍电流控制方法能够很好地实现单相三电平变换器的控制.实验结果验证了所提方法具有很好的输出性能,中点平衡也得到有效控制.

介绍了一种基于PCap02的电容式湿度检测系统的硬件和软件设计以及测试结果.硬件部分包括微处理器STM32407最小系统电路、电容式数字转换芯片P Cap02模块、RS485通信模块和系统供电模块等.软件部分主要包括基于STM32F407最小系统的软件设计、PCap02芯片电容数据采集转换程序以及RS485通信程序等.实际实验结果表明,该系统线性度好,具有良好的稳定性以及更高的精确度.

设计了一种以FPGA、温湿度传感器、数码管显示模块和执行机构为硬件核心,以LabVIEW为软件开发平台的实时温湿度参数监测系统.该系统通过温湿度传感器将采集到的库房内温湿度参数值传送给FPGA,并对其数据进行计算和处理后经串口传送给上位机进行处理和显示.测试结果表明,该系统实现了数据采集、处理及显示等功能,该系统操作界面简单、成本低廉,有利于减轻库房管理人员的工作量,提高物品的保存时间和品质,不仅适合库房温湿度的测量,在蔬菜大棚及其他需要测量温湿度等环境中也同样具有应用价值.

To improve the cost and accuracy in the positioning method of wireless sensor network in automatic devices, we proposed an improved distance based positioning method. We analyzed the positioning algorithm based on RSSI, TOA, TDOA, AOA distance measure. Due to different geographic shape, the right trajectory is important to the algorithm. We replaced hyperbola curve with asymptote in this study because the hyperbola positioning algorithm is not energy efficiency. We designed the positioning process of asymptote line algorithm. For the computational complexity, the hyperbola asymptotes are judged by the intersection point, which has an additional step compared to the maximum likelihood method. However, the maximum likelihood method must calculate the quadratic equations. The simulation results show that the algorithm proposed in this study is better than maximum likelihood method in positioning accuracy and the two algorithms have the same computational complexcity. The process of positioning presented in this study is simple and has a low cost.

According to the problem of analog circuit online fault diagnosis,a new method based on maximum interclass distance(MID) and regularized extreme learning machine(RELM) was proposed.Firstly,dimension of feature sample set was reduced using MID to get the new feature sample set with lower dimension and better separation.Then,the new sample set was sent for training RELM,sequently,the trained RELM can be used for real-time diagnosis of analog circuit,and on this process,feature sample set was renewed according to diagnosis result and similar degree between new test samples and old training samples.In the end,the proposed method was used in analog circuit diagnosis online.Simulation results of analog circuit online diagnosis show that the proposed method can diagnose both single and double faults effectively,which is better than ELM.

针对电子、电气类专业学生在创新性实践项目实施过程中暴露的问题和新升本科院校在电子设计竞赛中的困难进行研究,提出大学生创新性实验项目和电子设计竞赛相结合的教学模式进行探索,结合绥化学院的实践经验进行分析.实践表明,该教学模式既能保证创新实践项目的完成,又能促进电子设计竞赛取得较好成绩.

Analyzed the present status of the practice teaching of electrical information engineering in local colleges, that is suihua college, for example, firstly introduces the experimental conditions, laboratory resources, then, points out the several problems of the electrical engineering college practical teaching. Finally discussed around the college of electrical engineering talents cultivation core de-partment formulate "three levels, four platform" practice teaching mode. Practice shows that openness, comprehensive practice teaching system, better play to the role of the practice teaching in the cultivation of talents, has obtained certain achievements.

Ring acetone molecule dissociation channel are usual y described,for 2-methylcyclopentanone molecular is describes by two ways: they are the channel from the excited states to the products and the channel from the transition states to the products, but also thermal properties of other molecules is to be done..

交通事故中有很大一部分是由疲劳驾驶引起的,在各种疲劳驾驶预警技术中,基于脑电波的驾驶员疲劳驾驶监测技术是一种新型的汽车安全预警技术,研究其基本理论和实现方法对保证人身安全和减少交通事故都有重大的意义.

For MCU as the core of the control system is running slow distance,noise immunity is low and difficult to improve the measurement accuracy is insufficient,This paper presents an FPGA as the control center,echo detection method based on ultrasonic ranging system,mainly by ultrasonic ranging module,FPGA module and temperature measurement circuit modules.Experimental results show that:the system is fast, strong anti-jamming capability,high accuracy,avoidance of vehicles to meet user demand level measurement and other occasions.

This design used AT89S51 as the core control devices,realize 1 liter of water temperature automatic control in 10~70℃,and ensure that setting value is unchanged in a certain period.The temperature of water acquired by digital temperature sensors is transmitted directly into SCM.And real-time temperature is displayed through liquid crystal,at the same time draw up the curve of average temperature value with time changing.Single-chip microcomputer is adopted and use the solid state relay in order to control level 1 and level 2 refrigeration system in temperature adjustment stage and heating system startup and shut down. Through above steps,the water temperature control is achieved,the accuracy of 0.1℃temperature is guaranteed.Tests show that this system perfect function, well realize the design targets.

随着单片机技术的迅速发展，用单片机实现语音录放的开发与研究是近几年新兴的研究热点，单片机实现语音录放系统的研究是基于外围抗干扰电路、单片机、语音芯片及接口电路的综合应用。在确定系统总体设计方案的基础上，选择合适的芯片，并进行硬件电路设计，系统软件设计。最后硬件调试并成功，验证了本设计的可行性。

针对高频电子技术实验课教学过程中所遇到的问题,从实验课的实验方法、实验内容和实验管理体制等方面入手,提出了具体的改革方案。这些具体改革方案的实施,切实有效地提高了学生的实际动手能力,培养了学生的创新思维和创新能力。为今后的教学工作提供了新的思路和方法,可以全面提高实验教学质量。

通过介绍当前汽车电子仪表的基本功能,对PLC汽车电子仪表的数据处理流程进行说明,强调PLC电子仪表的多功能性与高可靠性,最后,根据汽车电子仪表的特点,提出应用时的注意事项.

在互联网高速发展的今天,存储设备成为了系统硬件当中的主要设备之一,而存储设备不仅可以在系统当中使用内置的磁盘之外,可当内置的存储磁盘不够大,并且没有多余的磁盘插槽可用时,linux存储技术孕育而生,除了linux下一切皆文件以外,linux还结合了世界级的NAS和SAN技术,存储管理,云支持,数据保护以及固态存储。它的力量是他能够灵活的支持截然不同的使用模式,它可以根据客户需求而提供不同的存储方式,这大大的提高的存储的高效性,安全性,稳定性。

文章描述了两种常见的数据库oracle和mysql,以及其安装平台Linux的简介,对数据库的基本块编写语言plsql进行说明；本文将着重的描述oracle、mysql这两种数据库,从数据库的起源发展、应用方向、oracle和mysql各自的特点等方向进行讲述,主要介绍数据库的体系结构、数据引擎、数据库oracle和mysql的关联、数据库的发展前景等.

The system with AVR MCU as a control core,realizes the speech recognition control.The system uses the main control chip Atmel ATMEGA128.ICRoute single chip LD3320 is adopted for speech recognition,in which the speech recognition algorithm is integrated without external FLASH and RAM resources.It′s a good way to complete the speech recognition task of non-specific person.MP3 player is integrated in the chip to support MPEG format.It can be used for voice prompt playback or MP3 songs.Due to internal containing 16 A/D,D/A converter and a power amplifier circuit,it can produce clear sound without any external power amplifier circuit.The system has reserved a variety of interfaces and has a good scalability.

DNS是域名解析系统(Domain Name System)的缩写,它是互联网的一项非常核心的服务,它的作用就是将IP地址和域名一一对应起来,这样当用户去访问互联网的时候直接打上域名就可以了。

This paper analyzes the status of SCM practice teaching.Integrate the school's training needs:applied talents as the goal;put forward the need for SCM practice teaching reform.From the MCU to adjust the content of practice teaching,improve teaching methods to explore aspects of teaching reform.

土壤电导的测量是本文的出发点,在分析土壤电导机理的基础上,构成了一个能同时检测土壤电导和土壤含水量的土壤电导试验系统。探索了土壤电导与土壤容积含水率、土壤含盐量之间的关系,得出了随含水量的增加土壤电导的变化趋势和土壤电导随土壤盐分含量的增加而变大的规律。同时还探讨了土壤电导与土壤pH值之间的关系,对pH值不同的土壤进行了分别的试验,通过分析认为土壤pH值对土壤电导的影响较弱,待今后再做深入的探讨。