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基于 LabVIEW 风机 性能 远程 测试 系统 研究

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基于LabVIEW的风机性能远程测试系统的研究,基于,LabVIEW,风机,性能,远程,测试,系统,研究

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编号无锡太湖学院毕业设计（论文）相关资料题目： 基于LabVIEW的风机性能 远程测试系统的研究 信机 系 机械工程及自动化专业学 号： 0923109学生姓名： 吴文进 指导教师： 陈浩 （职称： 高工 ） （职称： ）2013年5月25日目 录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计（论文）开题报告题目： 基于LabVIEW的风机性能 远程测试系统的研究 信机 系 机械工程及自动化 专业学 号： 0923109 学生姓名： 吴文进 指导教师： 陈浩 （职称：高工 ） （职称： ）2012年11月20日 课题来源 参考一些网络资料，文献资料，与指导老师商榷，最终从学校给定的课题中选定这一课题。科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）（1） 课题科学意义 评判风机的性能主要反应出三方面：产品质量的提高、工作效率的提高和工作质量保证。校验产品的气动性能能否达到设计要求、出厂的风机性能能否达到样本数据的要求、改造后的风机是否能达到性能指标都需要进行性能测试。性能测试也是诊断故障的前提。为了人们能正确使用风机，我们必须了解风机工作时输送流量、产生全压、所需功率及效率这些参数之间的相互关系。但由于风机理论至今尚未完善，所以大部分依赖于状态试验获取风机状态参数。长期以来，我国的风机测试技术比较落后，主要以手动操作试验过程、手工测量试验数据、手工绘制数据曲线为主，存在劳动强度大、测量精度低、测量手段落后等缺点。然而，现代风机性能测试正迅速从传统人工测试向自动化测试转变。计算机技术与测试仪器技术的结合，使得人类研发出了一种新的测试仪器虚拟仪器。由此，本文提出了利用NI 公司开发软件LabVIEW构建风机性能远程测试系统的方案。（2） 风机性能远程测试的研究状况及其发展前景风机性能测试是一项指挥协调较困难，技术性强又较繁杂的工作。传统手工测量的方法，其结果的准确性和可靠性难以保证。将虚拟仪器技术和计算机技术相结合，为风机性能测试的研究提供了一种新途径，特别是对一些风机作为生产关键设备的企业有着重要的意义，同时也为高校试验和科研单位提供了研究思路。虚拟仪器正在继续迅速发展。它可以取代测量技术传统领域的各类仪器。虚拟仪器在组成和改变仪器的功能和技术性能方面具有灵活性与经济性，因而特别适应于当代科学技术迅速发展和科学研究不断深化所提出的更高更新的测量课题和测量需求。网络化虚拟仪器是 Internet 技术融入到测控领域的新兴产物，代表了仪器仪表的发展方向，也是虚拟仪器技术在网络化方面的一大发展。它体系结构复杂，涉及的学科多、内容广，还有大量的理论和技术问题需要解决和再研究。作者认为风机性能远程测试还可以往以下几方面继续研究：（1）研究系统的在线实时监控性能，能够检测出系统的硬件故障；（2）根据网络化虚拟仪器数据存储需要，开发 Web 数据库写入与访问技术；（3）研究 B/S 模式的远程测试系统，克服 C/S 的缺点；（4）研究网络化虚拟仪器在应用中的网络安全问题，保证在网络上的传输数据不被第三方窜改、截获。研究内容1.对整个风机状态测试系统整体规划与设计。从整个系统的执行功能上，规划出风机状态测试系统整体设计方案。2.对采集系统包括：风机工况调节、系统测试的方法和原理、传感器的选用做出了详细的介绍和选择。3.根据测试原理及测试方案，编制出虚拟测试系统的结构，并对虚拟仪器测试系统的主要功能及其设计流程做了说明，并对系统的总体框架进行介绍，根据系统架构及其模块化的系统功能，设计了系统的主界面。拟采取的研究方法、技术路线、实验方案及可行性分析（1） 实验方案本文开发的是一套远程虚拟检测系统，主要通过测量风机的各个性能参数，对试验数据分析、处理等，并且用最小二乘法拟合出风机的性能曲线。从系统的硬件构成上看，系统主要有风机及配套设备、信号检测设备、数据采集单元和计算机等。从虚拟仪器系统的组成结构上看，本系统是一个典型的虚拟仪器数据采集系统，采用了数据采集卡，根据系统测试要求配合必要的传感器和信号调理电路来实现数据的采集。传感器检测风机的各个性能参数，检测信号经信号调理电路放大、滤波、整形等处理，然后通过DAQ卡的A/D转换等处理，送入计算机利用 LabVIEW编程来实现系统功能，最后通过网络传输数据，以实现数据共享，达到远程检测的目的。（2）研究方法 与通风机状态表相比，风机状态曲线更能连续、全面地反映其状态特性。本文是用控制变量法和试验法测得风机流量、全压、功率等参数并用最小二乘法拟合出风机状态曲线。 利用LabVIEW模块化、层次化及图形化的特点，将系统功能划分为选项设置、信号采集与控制、数据处理、试验数据读取和显示等模块，将这几个模块分别编程作为Sub VI，最后将各个功能模块组合起来，在主界面中调用这些Sub VI，从而完成系统的功能要求。研究计划及预期成果研究计划：2012年11月12日-2012年12月2日：按照任务书要求查阅论文相关参考资料，填写毕业设计开题报告书。2012年12月3日-2013年1月20日：填写毕业实习报告。2012年1月21日-2013年3月1日：按照要求修改毕业设计开题报告。2013年3月2日-2013年3月8日：学习并翻译一篇与毕业设计相关的英文材料。2013年3月9日-2013年3月30日：系统的整体方案的确立。2013年4月1日-2013年4月15日：风机性能试试验的原理和相关计算。2013年4月16日-2013年4月30日：采集系统设计以及风机远程测试系统的操作过程的实施。2013年5月1日-2013年5月21日：毕业论文撰写和修改工作。预期成果：软件采用 LabVIEW 开发平台，通过编写程序来实现信号的采集、分析、显示及存储等；系统采用模块化设计思想，针对风机性能测试的特点和系统软件总体设计，分模块设计各个程序作为 Sub VI，根据各个程序之间的功能关系进行调用，从而实现了信号采集的实时显示、存储等功能。利用 LabVIEW 的网络功能实现了信号采集的远程显示和结果输出，充分发挥了 LabVIEW 虚拟仪器设计速度快、方便、可扩展性高的优点，增加了测试过程的稳定性，避免人为的读数误差、计算误差以及相关数据不能同时记录所引起的测试结果的偏差，提高了试验精和试验效率。特色或创新之处 使用图形化开发平台“LabVIEW”进行数据采集和分析，效果明显，方便实验者操作，能够直观判断实验结果。 采用固定某些参量、改变某些参量来研究问题的方法，思路清晰，简洁明了，行之有效。已具备的条件和尚需解决的问题 实验方案思路已经非常明确，已经具备风机测试试验的计算和处理能力，深刻理解数据模块化方面的知识。 在LabVIEW平台上的编程的能力尚需加强。指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日英文原文Auto-testing system for fan performance basedon virtual instrumentation technologyAbstract: In accordance with the present status of measurement of fan performance with burdensome in labors, low inaccuracy and backward in testing method, auto-testing system for fan performance based on Virtual Instruments(VI)technology was developed. The system integrated sensor technology, computer technology and measurement technology.As a result, the system can not only automatically acquire, process testing data and express the final results in suitable forms but also control and adjust different working loads. The whole system is friendly in interface, easy in operation and complete in functions. The experiment results showed that the stability of the experiment process increased, the reading error was avoided and the measurement accuracy and experiment efficiency were improved. The system has been widely applied to many fan production factories and research institutes. Key words: fan; performance testing; auto-testing; virtual instrumentation; data processing1 Introduction The parameters of fan: flux, pressure, power an deficiency not only decide working performance but also are the basis of selecting and using blower for people. Because of the blower theory being not perfect, performance testing is the main method of acquiring these parameters. Moreover, the testing is important for testing products and designing new products. In China, traditional fan performance testing is always done manually or by single chip which has many shortages including lower precision, heavy labor intensity, unfriendly user-interface, and so on. Therefore, according to the demands of modern times experiment technique, an automatic test and analysis system for fan performance based on virtual instrumentation tool Lab Windows/CVI was designed in this paper. Combined sensor technology, computer technology and testing technique, the virtual instrumentation (VI) technology makes the most use of intelligence of computer to thoroughly break down the mode that the traditional instruments are defined by the manufacturers, however the users can not change. With VI, users are provided a space to exert their capacity and imagination adequately. It is the user, not the manufacturer, who can design their own. instrument system at their pleasure according to personal need. In the virtual instrument system, the hardware only provides a solution to the input and output of signals, however the software is the key to the whole system. Any user may modify the software to change, increase or decrease the functions and scales of the instrument system. As a result, the system can not only automatically acquire, process testing data and express the final results in suitable forms but also control and adjust different working loads. The whole system is friendly in interface, easy in operation and complete in functions. The experiment results have shown that the stability of the experiment process has increased, the reading error was avoided and the measurement accuracy and experiment efficiency were improved. The system has been widely applied to many fan production factories and research institutes.2 Hardware design of the system Hardware of this system, which is the basis of signal acquisition, conversion, enhance and processing, consists of fan, motors, wind pipe, sensors, computer, data acquisition board, frequency conversion governor, etc. The block diagram of system structure is shown in Fig.1. Among those components, computer and plug-in DAQ board play an important role in the system. With the high performance DAQ board, not only data acquisition, A/D conversion but also frequency control, step motor control etc are realized. Considered of the technical indexes such as sampling frequency, accuracy, A/D & D/A conversion rate, resolution, the DAQ board PCI-6024E from National Instruments (U.S.A), with which 200 ks/s, 12-bit performance on 16 single-ended analog inputs can be got up to, is selected. The 6024E features digital triggering capacity, as well as two 24-bit, 20 MHz counter/times; and 8 digital I/O lines. Two 12-bit analog outputs are also featured by the 6024E. The fan parameters: flux, static pressure, torque and rotation speed are measured by corresponding sensors including differential pressure transmitter ( BC69 type, accuracy is FS ), static pressure transmitter (JYB type, accuracy is 1%FS), and torque & rotate speed sensor ( AKC-205 type, accuracy is 0. 3%FS). The sensor outputs are all standard current signal with 420 mA. To meet the DAQ board input signal type and range, 0 5 V voltage signals are achieved from 420 mA current signals by an interface board which is used for signal transformation. Through the analog output channel on 6024E, 05 V voltage signal which is corresponding on 050 Hz of AC frequency, are sent out to control frequency converter (FR-A540-1.5K-CH type, MITSUDISHI, Japan). Then, the fan speed changes with variable voltage. The regulating unit of working status, which is designed by the authors, is the rotating baffle structure composed of round baffle, shaft coupling, creeper gear and step motor etc. (See the Fig.2). This kind of structure can not only realize the auto- control but also is small and flexible. Three digital I/O port on the 6024E are used to send out three- phase pulse to control the rotation angle of step motor. The step motor drives the round baffle through the creeper gear to revolve inside the wind- pipe, resulting in the change of aperture gap between the round baffle and wind-pipe, thereby altering the flux of airflow inside the wind-pipe, namely the alteration of working status is realized. The creeper gear can prevent the position of round baffle changing when the airflow is too strong. To insure the measurement accuracy, several anti-interference means are adopted such as differential inputs of signals to eliminate the common mode interference, good earth of signal line and instruments, digital filtering technology in software.3 Software design of the system3.1 Data processing Data processing in this system includes three aspects: processing acquired signals to weed out various disturbing signals; using hydrodynamics formulas to calculate performance parameters of fans; fitting performance parameters based on least square method to draw performance curves of fans. 3.1.1 Calculation of performance parameters Refer to the national standard GB1236-85, Aerodynamics performance test procedure of ventilator, the ventilator performance testing of the discharge outlet is achieved. The fan performance parameters are calculated as follow so: where is the aperture of restriction orifice; is the flow coefficient;is the gas expansion coefficient;is the gas density of fan outlet;Fit the torque between motor and fan;nis the rotation speed of motor;pst is the static pressure;Pd is the kinetic pressure;Ais the area of wind pipe;vis the speed of the airflow;is the available output. 3.1.2 Performance curve fitting There are many curve fitting methods such as exponential fitting, orthogonal polynomial fitting . The least square method is adopted to fit performance parameters because the characteristic curve of fan is mostly parabola. What is called least square method is statistically processing the observed values from experiments to make desired value of observation equal to its theoretical value and rectify the observed value. Using the function Polynomial that is in the advanced analysis library of Lab Windows/CVI, the performance curve fitting was completed. The format of function Polynomial is as follows:Polynomial(double x,double y,int n,int order, double z,double coef,double*mse) The purpose of this function is to find the coefficients that best represent the polynomial fit of the data points (x,y) using the least squares method. Poly Fit obtains the its element of the output array and mean squared error ( mse ) using the following formula: With this function the flux-whole pressure curve, flux-static pressure curve, and flux-efficiency curve can be achieved.3.2 Structure of the software The software is developed by Lab Windows/CVI which is an integrated ANSI C environment for engineers and scientists creating virtual instrumentation applications. With integrated I/O libraries, analysis routines, and user interface tools, Lab Windows/CVI delivers everything you need for building advanced test and measurement systems. Based on modular design method of program, 8 modules are designed in this system:(1) Basic parameters setting: user can key in the fan type and environmental parameters including atmospheric temperature, humidity and pressure in this module.(2) Data acquisition and control parameters setting: in this module, the sampling channel, control channel, sampling rate, signal input/output limit etc(3) Main control station: this module is the main interface for operators. The visualized controls, such as power switch, testing start switch, operating mode selecting slide, fan speed selecting slide, and real-time numeric &waveform display of signals, are delivered in the front panel for user operating this system conveniently.(4) Data processing: in this module, not only original data but also calculated data including flux, efficiency, power and total pressure can be shown in numeric and waveform form. Moreover, based on least square method the fan performance curve can be fitted with free selected fit module.(5) Test report: after test, operators can achieve the test report including grid or graph type of test dada in this module. Also, data saving, printing, exporting, importing etc are all realized.(6) History query: according to the test number and fan type, users can find history records they need with numeric or graph type documents in this module. Thus, a needed test report including fan performance curve can be displayed and printed.(7) Experimental simulation: a visual flash film is designed for operator to know the operating procedure well.(8) System help: using the hyper text technology, the system help on line is built which consists of three parts, namely, fan performance test system overview, background knowledge and operating instruction. In conclusion, the software system has key functions as follows: auto-acquiring parameters of fan performance, adjusting the rotating speed and flux of blower, auto-generating record of testing and performance curve, moreover, the software can also display, save and print these signals in graphic and numeric form. The whole system is friendly and convenient for operating.4 Experiment of the system Take the centrifugal blower (4-72 type) for testing example in laboratory, the performance testing experiment was made with this system. As shown in Fig.3, each point is the numerical value of test signal, and that connected line is the performance fitting curve based on least square method. Compared with handwork which was done at the same time, the two test results are nearly equal and the accuracy can completely meet the needs of national standard5 Conclusion From all above, the whole system has friendly functions, which can be used widely in scientific research institutes and factories. This system improves the stability of testing process, avoids the error of reading, calculation and result caused relative data can not be recorded at the same time with test artificially. As a result, the precision an efficiency of testing is largely improved. It meets the need of scientific production and auto-management modern industry. 中文译文基于虚拟仪器技术的风机性能自动测试系统 摘 要：我国风机性能检测多以手工为主，存在试验手段落后，劳动量大和测试结果不准确等缺点,采用先进的虚拟仪器技术，将传感器技术、计算机技术和测试技术结合起来，建立了基于虚拟仪器技术的风机性能自动测试系统，实现了试验数据的自动采集、风机转速的自动调节、风机运行工况的自动控制、试验数据的正确处理及性能曲线的自动绘制。整个系统具有界面友好、操作方便、功能齐全等优点。试验结果表明本系统增加了试验过程的稳定性，避免了人为的读数误差、计算误差以及相关数据不能同时记录所引起的试验结果偏差，提高了测试精度和试验效率。可广泛应用于科研院所和风机生产厂家，具有较高的推广应用价值。关键词：风机；性能试验；自动测试；虚拟仪器；数据处理1 介绍流量，压力，功率和效率等参数不仅决定工作绩效，也决定了工业生产的正常运作。由于风机理论不够完善，大部分依赖于状态试验获取这些参数。此外，测试最重要的是检验产品和创新设计产品。在中国，传统的风机性能测试是经常手动操作传统仪器从而获取参数，其中有许多不足，包括：精度不高、劳动强度大、不完善的用户界面，等等。因此，根据用户的需求和现代时代实验技术的发展，自动测试及分析风机性能系统应运而生。组合传感器技术，计算机技术和测试技术，虚拟仪器仪表技术的结合使得人们可以用最普遍的方法使用智能测试仪器，彻底打破传统技术由制造商制定用户不能改变的的模式。与此同时，给用户提供了一个空间，以发挥他们的能力和想象力不足。它是用户，而不是制造商，他们根据个人需要，他们可以设计自己的仪器系统。在虚拟仪器系统，硬件只是提供了一个解决方案，以输入和输出的信号为主的软件是整个系统的关键。任何用户可以根据需要修改软件，增加或减少软件的功能和软件的仪器系统。因此，该系统不仅可以自动采集、加工、试验数据，并以适当的形式显示最后结果，而且也控制和调整不同的工作负载。整个系统是具有完善的界面，易操作，并很好地完成功能。实验结果表明，稳定性试验过程中增加了，读数误差是可以避免和测量精度和实验效率得到了改善。该系统已广泛地应用于许多范生产厂家和科研单位。2硬件系统的设计硬件是这个系统的基础。包括风扇，电机，风管，传感器，计算机，数据采集板，频率转换器等。虚拟仪器测试系统的硬件通常包括传感器、信号采集、信号调理、等I/O接口设备和通用计算机。计算机一般是PC机或工作站，是整个硬件的核心，；传感器则是测试系统获取外界信息的通道；I/O接口设备则采集、放大、A/D、D/A转换被测信号等。LabVIEW获取数据的方法是通过对I/O接口设备的驱动完成的。虚拟仪器系统中，I/O接口设备主要是数据采集板。通过数据采集板获取数据在虚拟仪器中又称为PC一DAQ(Data Acquisition数据采集)式仪器。数据采集板作为仪器系统硬件的主要组成部分，是外界电信号与PC机之间的桥梁。它不仅具有信号传输的功能，还具有信号转换和译码的功能。风机工况调节的过程：由DAQ卡上的脉冲输出口输出脉冲信号加于数字电路板，控制步进电机的步进角度、正反转及步进速度；数字电路板用于脉冲分配和步进电机的驱动；将减速器加于步进电机与旋转挡板之间，用于防止风机运行过程中由于风力过大使挡板产生转动。通过编程，控制脉冲信号的个数和正反转信号，当用户发出指令改变风机运转工况时，PC机通过DAQ卡输出电压信号，此电压信号再经过电路转换，驱动步进电机使其转过设定的角度，控制旋转挡板的转动，这样就实现风机由工况1到工况10的调节，从而实现了流量的调节.该部件的工作状况制定，这是由作者设计制定的，是旋转挡板结构组成的轮挡板、联轴器、齿轮和步进电机等（参见图1），这种结构不仅可以实现自动控制，而且也有小而灵活的优点。为实现风管进口气流流量的调节，即风机工况的调节