Design of networking condition monitoring andfault diagnosis for wind turbine transmission system

In order to solve the incipient fault diagnose problem of the transmission system, a networking condition monitoring and failure diagnosis system based on B/S and C/S hybrid architecture for wind turbine transmission system is designed in the paper. Firstly, the paper analyzes the demands of condition monitoring and fault diagnosis system for wind turbine transmission system, and designs its overall framework and function modules. Then, combining with the data acquisition equipment, by the .NET and SQL Server platform, the paper designs condition monitoring and failure diagnosis system for wind turbine transmission system, which includes the functions of networking data acquisition, remote condition monitoring, signal analysis, fault diagnosis and database as well. The system has been successfully applied to a condition monitoring and fault diagnosis of wind turbine transmission system.     

Electro-circuit Design About the Data Acquisition and Wireless Transmission System Based on High-speed SCM

Considering the difficult of acquiring and transmission the signal from the moving equipment, a new fault diagnosis monitoring system is presented. The system acquires the state signal from the moving equipment by data acquisition module that based in W77E58 high-speed SCM, and transmits the data fast by wireless mode. The signal data can be use for fault diagnosis and precise analysis. The system has the ability for acquiring abundance of data with a high speed, the ability for high accuracy data conversion, and has a function of programme controlling gain and programme controlling low-pass filtering. The successful application of this system on the vibration monitor about the material-transporting bogie in an iron works of a domestic steel enterprise proves the stability and credibility about the design project, also testifies its practical value and versatility.     

The on line monitoring method of power transmission line fault basednon linear frequency response function

A novel method for power transmission line monitoring and fault diagnosis is proposed based on non linear frequency response analysis. The power line carrier signal has been used for on line monitoring of power transmission line. As the non linear frequency response function describes the system inherent characterization, different frequency response patterns corresponding to different operation states of transmission line can be established. Based on the analysis of transmission line characteristics of fault modes, various fault features can be extracted, thereby achieve online monitoring and fault diagnosis on transmission line. Simulation experiments show the effectiveness of the proposed method.     

Order Tracking Method Based on Time-Frequency Analysis

The fault character of moving parts of rotating machinery most time is speed related. The method of order spectrum analysis is more efficient than usual frequency analysis.Two general methods for realizing order tracking are discussed, and a new order tracking method based on time-frequency analysis is proposed. The time frequency order tracking method only depends on software for order tracking, which is a strong supplement to traditional methods, and specially satisfied the require of virtual instruments, so there is a good prospect for its using.     

State and Prospects of Diesel Engine Fault Diagnosis Technique

As a kind of complex power machinery, diesel engine is being paid more and more attention to its condition monitoring and fault diagnosis technology. In the fault diagnosis field of diesel engine, the technique of signal process, character abstraction and identification method have formed a system, but there is a certain distance away from practical. This paper analyzes the common faults and influencing factor of diesel engine. The principle, characteristic and disadvantage of modern fault diagnosis technology, such as various time-frequency methods based on vibration signal, speed fluctuation method, iron content and spectrometry, grey system theoretical diagnosis method, artificial neural network and expert system fault diagnosis method, were reviewed. The difficulties and the development direction of diesel engine fault diagnosis were put forward in the end.     

Research of Compressor Maintenance Service System Basis on Web

The significance and current-situation of running remote maintenance are introduced. The model of maintenance service system is built on the basis of studying units. The system construction, software and hardware environment are debated. The signal monitoring software system of compressor is implemented by programming with assemble language and C language. The virtual instrument applied to on/off-line signal processing is established on the basis of Labwiew. The maintenance decision supporting system interior enterprise with TCP&UDP and the remote maintenance service system adopting B/S model are dwelled. The system is practicability testified. The goal of system developing is the integrated of all kinds of MIS.     

Development of Virtual Sweep Signal Source

A new kind of virtual sweep signal source which can be used to output specific sweep signal according to(users') configuration and can be widely applied to frequency characteristics measurement in the field of mechanics,electrics and electronics,is developed by using Dot Net software engineering technique,C/S architecture and general data acquisition platform.The virtual instruments not only make up the intrinsic defect of traditional instruments based on hardware components in high performance,remote control and data processing,but also indicate the powerful life and nice future of virtual instrument technologies.     

Signal Processing of Electroencephalogram and It''s Application

Electroencephalogram (EEG) signals are the electrical activities in the cortex or on the surface of scalp caused by the physiological activities of the brain which play a key role in the diagnosis of brain and the functional determination of brain. The authors discuss some methods for processing EEG signals from the view of the frequency domain and time domain, especially introduce some time-frequency analysis methods such as Wigner distribution, wavelet transform and matching pursuit etc. , ANN and non-linear analysis for EEG signals processing.     

东北地区湿地遥感监测评价业务系统

为实现国产风云三系列卫星数据进行东北地区湿地变化的动态监测及业务化运行,采用面向区域的虚拟框架结构设计和多种类型“层”数据协同处理的方式,实现FY3/MERSI、EOS/MODIS、TM等多源多通道卫星数据的数据定标、投影、几何校正及数据重采样等功能,同时提供地理信息背景数据和相关辅助信息叠加、提取等功能,针对湿地特点,进行植被指数、水体指数、蒸发散等湿地下垫面特征参数指标计算,多源遥感数据处理和融合与数据分割,湿地专题图制作等,为用户提供方便、可信的业务系统,为东北地区湿地保护、灾害防御提供了科学的参考依据。     

Frequency Refining Analysis and Its Applications in the VIs

Frequency refining is an important spectrum analyzing tool, and is one of the main function of signal processing and the virtual instrument. This paper introduces several typical frequency refining analysis methods including DFT and multiple modulation and so on. It also probes into their advantages and disadvantages, and proposes a new frequency refining method combining subband decomposing DFT and multiple modulation, which inherits the advantages of multiple modulation, needs not to design a specific filter, reduces the amount of calculation, and is fit for real-time refining analysis. At last, it exhibits several frequency refining algorithm and their effects with applications in virtual instruments.     

Time-frequency Characteristic of Wavelet Base and Its Application Transient Signal Detection

The application of wavelet analysis in fault diagnosis is growing rapidly.There are many different wavelet base to use but no accepted procedure for choosing among them, the analysis results by using them have great difference. This paper describes the significant properties of wavelet base, and analysis behavior of transient signal in wavelet transform, result on some methods for how to choose wavelet base in analysis transient signal.     

基于MODIS-NDVI时序数据的南方冬闲田信息提取

为了从宏观上监测冬闲田的面积及分布情况有效解决传统方法的时效性差的缺陷,以MODIS-NDVI时间序列数据、土地利用数据和湖北省农业统计数据为基础,得到2007年4月到2008年3月湖北省MODIS-NDVI时序数据变化曲线。由于遥感影像在传输过程中受到云、大气等的影响,曲线的变化与统计数据的物候期并不完全符合。为了如实反映地表事物的真实面貌,本文采用Savitzky-Golay滤波进行平滑去噪处理,并将结果与ERDAS中自带的Hanning滤波去噪的结果进行比较,发现前者效果较好,不仅能有效去掉噪声,不产生环形条纹,而且能最大程度地保留细节特征。根据变化曲线所反映的物候信息,最后得到湖北省冬闲田的总面积为5564.3平方千米,即834.6万亩,占耕地总面积的16.6%,主要分布在鄂东南低山丘陵和江汉平原地区,冬闲期主要有60天和120天两种。     

日光诱导叶绿素荧光遥感探测的研究进展

对陆地植被的生物物理参数和生物化学参数进行反演,对夫琅禾费暗线中的叶绿素荧光信号进行提取是植被高光谱遥感的三项基本任务。鉴于叶绿素荧光与光合作用存在密切的联系,叶绿素荧光参数和稳态荧光光谱特征在植物健康状况的评价,环境胁迫因子的早期检测应用中表现出很大潜力,围绕叶绿素荧光遥感的研究快速发展起来。本文结合国内外最新的研究进展对稳态荧光的光谱特征及其产生机理;日光诱导叶绿素荧光信号的检测方法;遥感探测器的类型及工作原理;叶绿素荧光的建模与仿真现状进行了综述;也对叶绿素荧光在非生物胁迫子早期检测、植物病害监测与病情评估领域中的应用进行了综述;对叶绿素荧光遥感研究工作的重点作了展望。     

Assembly fault rate analysis using grey relation and least squares support vector machines

To get the relationship between assembly fault rate and its attributes, least squares support vector machine (LSSVM)is introduced to quantitatively study assembly fault rate. Aiming at the drawbacks of assembly reliability evaluation method(AREM), the attributes of assembly-fault-rate-affecting 5M1E(Man, Machine, Material, Method, Measurement and Environment) factors obtained by AREM are improved, hence the LSSVM model with all attributes is established. To reduce the time of calculating the assembly fault rate and provide the priority for assembly reliability improvement, grey relation analysis is applied to extracting the main attributes, at the same time genetic algorithm(GA)is used for parameter optimization in LSSVM. The assembly fault rate analysis results show that the method using grey relation analysis and least square support vector machine is simpler and more accurate compared with other methods such as LSSVM model using all attributes and BP neural network using main attributes.     

无人机遥感在作物监测中的应用研究进展

无人机作为新型遥感平台,近年来发展迅速,应用领域不断拓展。无人机遥感技术被广泛用于作物监测,在农田作物长势监测、农作物营养诊断和产量估测等方面有所突破。本文从无人机遥感技术的特点、无人机平台的选择和传感器类型、在作物监测上的主要应用3个方面做了较为详细的综述,对无人机发展的难点进行了讨论,并对无人机遥感技术在作物监测上应用进行了展望。     

Parameter optimized Morlet wavelet de noising method based on cross validation method

A new de noising method based on parameter optimized Morlet wavelet is put forward. The Morlet wavelet is chosen as the mother wavelet because its shape is similar to the mechanical shock signals. The mother Morlet wavelet is improved by adding two parameters which decide the shape of the mother wavelet in time domain. The added parameters and the appropriate scale parameter for the wavelet transformation are designed by the cross validation method. Finally, the useful components of the signal can be obtained by the improved Morlet wavelet de noising method. The gear fault diagnosis experimental result shows that the proposed method has a good de nosing performance and it is effective in fault feature extraction.     

PD Online Measurement of Transformers with Wide Frequency Band System and the Noise Eliminating Method by Cascaded IIR Lattice Notch Digital Filter

The frequency band of conventional partial discharge (PD) measurement systems is selected just within several ten kilohertz. With the development of computer and digital signal processing techniques, wide frequency band (WFB) measurement systems have been used to detect PD in electrical equipment for its higher sensitivity. Nevertheless, the WFB measurement systems are easy suffered from the interference of strong field electromagnetism noises. A set of PD online monitoring system with frequency band from 50 kHz to 1 megahertz used for transformer is developed, in which pre-processing device and cascaded 2nd order IIR lattice notch digital filter are mainly used to suppress periodic narrow-band interference. With analysis of field monitored signal at a 220 kV substation, it is shown that the monitoring system not only can detect and extract the discharge pulse signal effectively, but also has the powerful capability of suppressing interference.     

物联网技术在小麦气象灾害监控诊断系统中的应用研究

针对小麦生长周期长,容易遭受多种气象灾害的情况,设计了基于物联网的小麦气象灾害诊断系统。本系统根据多年农学实验研究成果,通过建立小麦气象灾害诊断指标体系规范,并采用传感器技术、网络传输技术、Webservice技术和Socket调用技术等集成,搭建了基于小麦生长环境实时监测数据的苗情和气象灾害诊断平台。该平台具有异地数据资源共享、分布式管理的功能,能在多种网络通信环境下实现苗情监控和灾害诊断,为小麦生产科学管理、防灾减灾提供了有力的技术支持。     

Design and Realization on Remote Condition Monitoring System for Feeding Oil Pump

In view of the actuality of the feeding oil pum monitoring,the network technology,the database technology and the Dot Net remote technology are integrated nimbly to construct the remote condition monitoring system for feeding oil pump,which has many functions such as the real-time data monitoring and alarm,real-time monitor data storage remote monitoring,network data sharing,fault analysis,and so on.The whole construction design of the system and the realization of its sub function are given.The worker's intensity of labor,the maintenance cost and the accident occurrence rate of the feeding oil pum were dramatically reduced when the system was applied to the oil storeroom successfully.     

北方果树霜冻害远程监控与报警系统初步研究与实现

为提高北方果树防霜冻害管理水平,基于物联网架构,设计实现了北方果树霜冻害监测与报警系统。该系统结合实时获取果树生长环境数据,及果树霜冻害发生规律和专家知识库,为用户提供远程果树环境信息分析和霜冻害智能诊断服务。同时为满足不同生产条件需求,结合用户需求和环境状况,提供自动报警。根据用户随时随地获取信息的需求,基于多种网络技术等(如Internet、android等移动互联网),开发了可用于PC终端、移动终端(如智能手机、平板电脑等)多平台管理模式。通过提供现场综合远程实时监控、数据采集、网络传输、数据管理分析及报警预警等功能,系统实现了对果树生长的全方位多功能的远程监控与综合管理,有效提高了果树防霜冻害监控管理水平。