关 键 词：

机械 基于 虚拟 测试 技术 风机 状态 状况 系统 设计 cad 图纸

资源描述：

机械基于虚拟测试技术的风机状态测试系统的设计带CAD图纸,机械,基于,虚拟,测试,技术,风机,状态,状况,系统,设计,cad,图纸

内容简介：

摘要摘要风机状态试验是在风机转速不变的情况下，改变风机运行工况、测量试验数据、计算风机状态参数并绘制状态曲线(流量一全压曲线、流量一功率曲线、流量一效率曲线)的过程。它对于成品的检验和新产品的开发至关重要。目前，我国风机状态检测大多以手工为主，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，将传感技术、仪器技术和测试技术结合起来，进行风机状态参数的自动检测，试验数据的自动处理和状态曲线的自动绘制是本文研究的重点。本文采用虚拟仪器技术，进行了风机状态试验自动测试系统的硬件及软件设计。硬件上采用压差传感器、压力传感器和扭矩传感器检测各试验数据，实现了试验数据的自动采集；利用变频调速技术控制变频调速器输出信号的频率，实现了风机转速的自动调节;通过设置旋转挡板装置并用步进电机控制其旋转角度实现了风机运行状况的自动控制。软件上在LabVIEw虚拟仪器开发平台上，采用模块化设计方法，实现了采集信号的实时显示、控制信号的准确输出、试验数据的正确处理及应用最小二乘法对状态参数进行拟合从而实现了状态曲线的自动绘制。整个系统具有界面友好、操作方便、功能齐全等优点，试验结果表明研制基于虚拟仪器的风机状态自动测试系统，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的偏差，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：风机状态：虚拟仪器：自动采集：自动控制：labviewI毕业设计(论文)任务书系别 ：机电工程学院 专业：机械设计制造及其自动化 班级：机0405学生情况指导教师情况题目类型姓 名学 号姓 名职 称单 位理论研究 科研开发 胡发振34王会香讲师机电工程学院工程设计 论文 题目基于虚拟测试技术的风机状态测试系统的设计主要内容以及目标主要内容：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、 对整体系统的状态测试系统的进行规划设计，对系统的硬件接口进行设计，并绘制出测试系统的电器分布图。3、 根据测试原理及测试方案，编制出良好的测试VI程序。4、 应用设计的VI程序进行测试实验。目标：完成风机状态测试系统整体规划与设计，对系统的硬件接口进行设计，并通过使用图形化的编程语言Labview 编制测试程序，实现对实际的风机状态参量进行测量与分析处理的目的。并撰写毕业论文，达到机电一体化综合能力训练的目的。成果形式具体工作量：1.3000字的开题报告一份； 2.与毕业设计相关的英文翻译一份，5000字以上； 3.完成机械图纸A 2张，编制状态测试程序； 4.撰写一篇15000字以上的关于基于虚拟测试技术的风机状态测试系统的总体设计的毕业论文。成果形式：论文、图纸、 VI程序。基本要求1、设计图纸符合国家标准，2、结合机械与机电的有关知识对系统进行设计。实习调研要求实习调研提纲：1、风机状态测试系统的组成。2、熟悉风机工作过程中的各种状态的测试信号的作用。实习调研时间：第1-3周实习调研地点：机电控制重点实验室主要参考文献1. 主要仪器设备计算机， 工控机。PCI数据采集板卡毕业设计（论文）开始日期2007-3-1毕业设计（论文）完成日期2007-6-27毕业设计（论文）进度计划（起止时间、工作内容）1. 第1-3周 实习调研基本结束；2. 第4周 撰写并提交调研报告和开题报告；3. 第5-6周 系统的整体方案的确立；4第7周 绘制风机总貌图；5. 第8-9周 对系统的硬件接口进行设计6第10-13周 根据测试方案，编制VI程序；7第13-14周 应用VI进行实验并处理相应的数据；8第15-16周 撰写并提交毕业论文；审阅、评审并修改毕业论文；9第17周 完成毕业答辩指导教师（签字）： 年 月 日督导教师（签字）： 年 月 日系毕业设计（论文）领导小组审查意见：组长（签字）： 年 月 日摘要风机状态试验是在风机转速不变的情况下，改变风机运行工况、测量试验数据、计算风机状态参数并绘制状态曲线(流量一全压曲线、流量一功率曲线、流量一效率曲线)的过程。它对于成品的检验和新产品的开发至关重要。目前，我国风机状态检测大多以手工为主，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，将传感技术、仪器技术和测试技术结合起来，进行风机状态参数的自动检测，试验数据的自动处理和状态曲线的自动绘制是本文研究的重点。本文采用虚拟仪器技术，进行了风机状态试验自动测试系统的硬件及软件设计。硬件上采用压差传感器、压力传感器和扭矩传感器检测各试验数据，实现了试验数据的自动采集；利用变频调速技术控制变频调速器输出信号的频率，实现了风机转速的自动调节;通过设置旋转挡板装置并用步进电机控制其旋转角度实现了风机运行状况的自动控制。软件上在LabVIEw虚拟仪器开发平台上，采用模块化设计方法，实现了采集信号的实时显示、控制信号的准确输出、试验数据的正确处理及应用最小二乘法对状态参数进行拟合从而实现了状态曲线的自动绘制。整个系统具有界面友好、操作方便、功能齐全等优点，试验结果表明研制基于虚拟仪器的风机状态自动测试系统，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的偏差，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：风机状态：虚拟仪器：自动采集：自动控制：labviewAbstractBlower Performance testing is the course of changing working states，measuringtesting dates，calculating Performance Parameters and plotting Performance curves which processed under the certain rotate speed. It is important to inspecting finished production and designing new production. At present, blower testing work is handwork mostly in our country, which has some defects such as obsolete testing means, large labor and imprecise result. So applying the virtual instrumentation technology which combining the sense technology, instrumentation technology and testing technology to test performance parameter, process data and plot curve is the key points in this paper. Applying virtual instrumentation technology, the author designed the hardware and software of the blower performance testing system. In the hand of hardware, testing data is acquired automatically according to press-difference sensor, press sensor and torch sensor, blower speed is adjusted automatically according to frequency conversion of transducer and working state is auto controlled according to rotating baffle controlled by the step motor. In software, the module design method is applied. The acquired dates are showed real-timely and controlled message are output precisely in the developing platform-labview, other well, the performance curve is completely gained in applying least square method. The whole system has friendly interface, convenient operation and comprehensive functions, which can be used widely in scientific research institutes and factories. The system of blower performance auto-testing improves the stability of testing process, avoids the error of reading, the error of calculation and the error of result causing by relative dates can not be recorded at the same time, the precision and efficiency of testing is largely improved. Keywords: blower performance; virtual instrumentation; auto-acquire; auto-control; labview目录摘要（中文） （英文）第一章 概述 1第二章 系统总体方案的确定 22.1 风机状态试验方法 3 2.2 虚拟仪器技术及其应用 32.3 基于虚拟仪器的风机状态试验方法 4第三章 系统硬件设计 53.1步进电机的控制 53.2风机转速调节装置的设计 73.3试验数据的检测 8 3.4数据采集板 12 第四章 系统软件设计 14 4.1 软件平台 144.2 检测信号的计算机处理 144.3 软件结构及功能 174.4 软件使用说明 18第五章 系统可靠性设计 205.1 系统抗干扰分析 20 5.2 硬件抗干扰 205.3 软件抗干扰 21结束语 23 参考文献 24 IIIAuto-testing system for fan performance basedon virtual instrumentation technologyQian Dongping1,Huo Xiaojing1,Guan Zhenzhen1,Yang Shifeng2(1.College of Mechanical and Electronics Engineering,Hebei Agricultural University,Baoding071001,China;2.School of Electronic Information and Automation,Tianjin University of Science&Technology,Tianjin300222,China)Abstract: 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 suitableforms but also control and adjust different working loads. The whole system is friendly in interface, easy in operation andcomplete in functions. The experiment results showed that the stability of the experiment process increased, the readingerror was avoided and the measurement accuracy and experiment efficiency were improved. The system has been widelyapplied to many fan production factories and research institutes.Key words: fan; performance testing; auto-testing; virtual instrumentation; data processing1 IntroductionThe parameters of fan: flux, pressure, power an defficiency not only decide working performance butalso 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 singlechip which has many shortages including lower precision, heavy labor intensity, unfriendly user-interface, and so on13.Therefore, according to the demands of modern times experiment technique, an automatic test and analysis system for fan performance based on virtual instrumentation tool LabWindows/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 system4, 5.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 systemHardware 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 samplingfrequency, 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 6024E6.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 software7.3 Software design of the system3.1 Data processingData 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 GB1236-858, 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 dnis the aperture of restriction orifice; is the flow coefficient;is the gas expansion coefficient;is the gas density of fan outlet;Fis the torque between motor and fan;nis the rotation speed of motor;Pstis the static pressure;Pdis 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 and Chebyshev 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 value9. Using the functionPolyFitthat is in the advanced analysis library of LabWindows/CVI, the performance curve fitting was completed. The format of function PolyFit is as follows: PolyFit(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. PolyFitobtains theithelement of the output array and mean squared error ( mse ) using the following formulae7: where xis flux;yis whole pressure, static pressure, power, and efficiency respectively;zis best fitted value ofy;orderis polynomial order;nis number of sample points;mseis mean squared error.With this function the flux-whole pressure curve, flux-static pressure curve, and flux-efficiency curve can be achieved.3.2 Structure of the softwareThe software is developed by LabWindows/CVI which is an integrated ANSI C environment for engineers and scientists creating virtual instrumentation applications10. With integrated I/O libraries, analysis routines, and user interface tools, LabWindows/CVI delivers everything you need for building advanced test and measurement systems. Based on modularization 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 etc3) 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 ConclusionFrom all above, the w