外文翻译---脉冲输出型数字涡街流量计的研究.docx

附录AResearch on pulse output model digital vortex flow metersThe vortex flow meter is widely used in different fields due to its flexibility to various media, non-mobile parts, simple structure and long life etc. However, it has poor performance when operating at low flow rate where the Signal-to-Noise ratio is very small or even the signal is submerged by the noise. The traditional analog vortex flow meter has benefits of steady signal, high accuracy and good real time in the regular flow range, while it also has a disadvantage of weak signal difficult to detect at low flow rate, which leads to unsatisfying lower limit and a smaller range ratio of 10:1.Based on the previous efforts a pulse output model digital vortex flow meter is developed successfully, which inherits the advantages of the analog one and make up its shortage mentioned above. The digital vortex flow meter with its double-core structure that means a couple of CPUs made up of DSP and MSP430 identifies the vortex signals from noises by the frequency spectrum analyzing algorithm in DSP at low flow rate where the analog one is not accurate, or even cant work. Meanwhile it works out by its microcontroller MSP430 the frequency of the vortex signal that is square waves output from pre-amplifier for the vortex signals in the regular flow range where the Signal-to-Noise ratio isnt too much small and the analog one is accurate and real time.This dissertation consists of theory, hardware/software design and experiment. The main point includes:1.The scheme called double-channel work model of the pulse output model digital vortex flow meter is designed. The principle is a switch of two different methods to detect the vortex signal. That is using spectrum analysis of digital signal at low flow rate and frequency counting like analog vortex flow meters in the regular flow range. The critical criterion of the switch point is the uncertainty of the frequency.2.A pulse output model digital vortex flow meter is developed successfully. The flow meter is studied respectively at DN25 and DN50 pipelines of the water flow experiment facility and DN50 and DN100 pipelines of the gas flow experiment facility that locate at Process Detect & Control Laboratory in Tianjin University. And the data shows that the digital flow meter has the property of a better lower limit than the analog one and a bigger range ratio of 1:28.541.3. Masses of experiments on the digital vortex flow meter have been carried out at the water flow experiment facility and the gas flow experiment facility of Tianjin University respectively. The result shows that the pulse output model digital vortex flow meter has a satisfying lower limit that increases the range ratio effectively, strong ability and good real time and thus it is of great practicability.The 21st century is the century information, information and materials and new technology as the main pillar of society from the human revolution is industrialization era to information era, as the perception, acquisition, conversion, processing and transmission of information technology and the indispensable testing instrument, has become an important technology and computer equivalent and daily life and production of all fields. Along with the rapid development of science and technology, industrial production get continuous development, the detection technology and puts forward many new requirements, and new technology and instrument appearance and further promote the development of science and technology, the development degree of detecting technology has decided to science and technology level, in other words detection techniques and instruments is the measure of modern science and technology level of a mark. This one, as testing technology is an important part of flow metering with national economic and national defense, science and technology, the close relationship in economic development plays an important position.After continuous efforts, and technical workers have developed pyretic and various characteristics of flow meter. According to the measuring method and the structure of the classification method, will be divided into differential pressure meter flowmeter, volumetric flowmeter, fluid flow, ultrasonic vibration flowmeter, mass flowmeter, insert flowmeter open-channel flow and other flowmeter, 11 kinds . The research of the vortex flowmeter belongs to the hydrodynamic vibration flowmeter are widely used .Vortex flowmeter is according to the fluid velocity of vibration frequency and the corresponding principle of work. As early as in 1878 straw Strophe published about fluid velocity relationship with the vibration frequency, straw, vortex frequency is said to stop features of similar size and the velocity of the relationship. People in the early vortex research mainly is the purpose of prevention. Vortex flow vibration phenomenon for measuring the study began in the 1950s, such as wind meter and ship speed gauge etc, at the end of the 1960s began to develop close pipeline flow - vortex flowmeter. 1970s and 1980s vortex flowmeter unusually quick development, development outstanding type resistance fluid and detection methods of vortex flowmeter, and mass production, such as the market in just a few short years time to arrive from laboratory batch production process of the sample flow is unique.Vortex flowmeter is a fluid vibration flowmeter, set in the fluid flow vortex happened (resistance from vortex happen) alternately on both sides of the body produces regular vortex, the spiral called Carmen vortex, swirling in spiral happen asymmetrical body downstream, vortex flowmeter is arranged by measuring the vortex frequency and realization of flow measurement.Vortex flowmeter by sensors and switches two parts. Sensors (including vortex flow resistance occurs, components, instrument) such as table, converter including pre-amplifier, filtering plastic circuit, D/A transformation circuit, output interface circuit, terminals, bracket and shields, etc. In recent years, intelligent flowmeter is the microprocessor, communications and other functions that are installed in converter module.According to the detection means, vortex flowmeter stress can be divided, capacitive and thermal type, type of ultrasonic vibration, strain, and photoelectric and fiber, etc. Among them, stress (also called the piezoelectric) vortex flowmeter with its fast response and strong signal, working temperature range wide, strong adaptability and high reliability etc, has become the main products vortex flowmeter type. This vortex flowmeter, it is to test the lift in form stress testing devices, piezoelectric conversion variable charge signal, clinch a deal the charge amplifier, filtering, plastic after vortex signal. Piezoelectric sensor signals, fast response and low cost, manufacturing process, but is more sensitive to vibration.As mentioned, vortex flowmeter has many advantages, and there are many problems to be solved, especially in the measurement of small flow, vortex useful signal is very weak, yi was drowned, low noise signal under the velocity measurement caused great difficulties. In order to solve this problem, the domestic and overseas scholars and scientific research institutions in research and application of various solutions, namely of digital signal processing method to solve, but most just stay in the research on the method of high efficiency, and not be applied algorithm support for production. At present, the domestic production of the vortex flowmeter is limited to the analog circuit application method of vortex signal processing (called simulation vortex flowmeter), this can not solve the low SNR, leading to lower the problem than only achieve high, range 1:1 scale theory, far below zero. Foreign company, Yokogawa only Rosemount and ABB has developed the application of digital signal processing methods of signal processing vortex, namely digital vortex flowmeter, but specific technology is not open.In recent years, the vortex signal processing methods about the study many (such as wavelet method of adaptive LMS changes, etc), the algorithm of tianjin university professor zhang tao presided over the research of vortex sensor output signal for exploration of digital signal processing won great progress. Ling Qing master according to the signal features and vortex of signal processing method, the requirements for maximum likelihood estimation results in cycle chart are put forward on the basis of more suitable for relaxation of the vortex frequency estimation method of graph, commit cycle and the simulation experiments. This method with high resolution and high frequency characteristics of the calculation efficiency, strong resistance to complex noise interference ability. WuPeng master based on wavelet transform, deposing principle of flow measurement specific requirements, and puts forward a suitable vortex flow sensor signal processing methods of single reconstruction filter is given, and the method of selecting, filter series of this method can effectively expand vortex flow sensor range. However, due to the above two methods, the complexity of algorithm, real-time computation is not guaranteed, and applied in practice.Along with the Digital Signal Processor Digital Signal processing (DSP) technology, referred to the rapid development and wide application, make complex Signal processing algorithm can achieve in hardware. DuanRuiFeng master a set of DSP and MSP430 microcontroller combination of the vortex digital signal processing system, using slack trapped cycle graph method for calculating the vortex flowmeter signal frequency. Experimental results show that the vortex flow dual-core digital signal processing system can effectively reduce the measurement limit (mm diameter measurement can reach vortex lower 0.323 m3 / h), realize the real-time data processing.This topic is on the basis of research achievements in domestic production, the vortex flowmeter is limited to simulate the vortex flowmeter, research and implementation of a practical pulse output type vortex flowmeter figures. The pulse output type digital vortex flowmeter using MSP430 MCU based on DSP and the twin CPU hardware structure, small flow in low velocity by DSP based on fast Fourier transform (FFT) form fast, referred to as the power spectrum estimation is proposed to measure vortex frequency real-time pulse output, When the flow in the normal flow range analogue circuit, signal preprocessing vortex, then by microcontroller program flow calculations, display, frequency, pulse output etc. The digital pulse output type vortex flowmeter in tianjin university experiment device and gas flow flux on doing a lot of experiments, the results show that the instrument effectively expand the scale of the vortex, lower than the measuring low, repeatability, strong anti-jamming ability, good real-time, etc.附录B脉冲输出型数字涡街流量计的研究涡街流量计因其介质适应性强，无可动部件，结构简单、使用寿命长等诸多优点，在许多行业得到了广泛的应用。而在低流速下，涡街测量就显现出了它的不足，涡街信号的信噪比很低，有用信号几乎被噪声淹没。普通的涡街流量计采用模拟信号处理方法，在正常流量范围内，涡街流量信号稳定、测量准确、实时性好；而在小流量下，涡街有用信号微弱、提取困难，导致实际测量下限比较高，量程比小，一般为10：1。鉴于上述模拟涡街流量计具有的优势以及存在的不足，课题在前人研究成果的基础上，研究并成功地实现了一台实用的脉冲输出型数字涡街流量计。该数字涡街流量计采用了基于DSP和MSP430单片机双CPU的硬件结构，在低流速小流量的情况下，由DSP实现频谱分析算法来计算涡街信号频率，有效地克服了模拟涡街在小流量下测量精度不高甚至不能测量的问题；在正常流量范围内，由单片机对涡街信号前置放大电路输出的方波进行计频，具有常规模拟涡街在高信噪比的情况下测量准确、实时性好的优点。本文从原理分析、硬件软件设计和实验研究三方面来研究，主要内容包括：1.设计了脉冲输出型数字涡街流量计的总体方案，尤其是采用了双通道处理的方式，将低流量下数字信号处理的频谱分析功能和正常流量范围内智能涡街的计频功能有机地结合起来，并引入了频率不确定度的概念作为判断涡街有用信号双通道处理方法的依据。2.成功实现了一台脉冲输出型数字涡街流量计。通过在天津大学过程检测和控制实验室的水流量实验装置上进行的25mm口径和50mm口径实验研究，以及在气体实验装置上进行的100mm和50mm口径实验研究的结果表明，本脉冲输出型数字涡街流量计有效地降低了涡街的流量下限，使量程比显著扩大，量程比达到1：28.541.3。将此数字涡街分别在天津大学水流量实验装置和气体流量实验装置上做了量的实验，结果表明本脉冲输出型数字涡街流量计具有很低的测量下限，有效扩大了涡街的量程比，抗干扰能力强，实时性好，具有很高的实用价值。21世纪是信息的世纪，以信息、材料和生物为主要支柱的新技术革命正将人类社会从工业化时代推向信息化时代，作为感知、采集、转换、处理和传输各种信息不可缺少的检测技术和仪表，已成为与计算机同等重要的技术而深入日常生活及生产的所有领域。随着科学技术的突飞猛进，工业生产得到不断发展，对检测技术又提出了许多新的要求，而新的检测技术和仪表的出现又进一步推动了科学技术的发展，故检测技术的发展程度决定了科学技术的水平，换句话说检测技术和仪表是衡量现代科学技术水平高低的一个标志。这其中，作为检测技术重要组成部分的流量计量由于与国民经济、国防建设、科学技术的密切关系，在经济发展中占有重要的地位。经过不断的努力和探索，科技工作者已开发出种类繁多、各具特色的流量仪表。按照测量方法和结构的分类方法，将流量计分成差压式流量计、容积式流量计、流体振动式流量计、超声流量计、质量流量计、插入式流量计、明渠流量计和其他流量计共十一大类。本课题研究的涡街流量计属于流体振动式流量计中应用最为广泛的一种。涡街流量计是依据流体振动频率与流速有对应关系的原理进行工作的。早在1878年斯特劳哈（Strophe）就发表了关于流体振动频率与流速关系的文章，斯特劳哈数就是表示涡街频率与阻挡体特征尺寸、流速关系的相似准则。人们早期对涡街的研究主要是防灾的目的。涡街流体振动现象用于测量研究始于20世纪50年代，如风速计和船速计等，60年代末开始研制封闭管道流量计涡街流量计。70、80年代涡街流量计发展异常迅速，开发出众多类型阻流体及检测方法的涡街流量计，并大量生产投放市场，像这样在短短几年时间内就到达从实验室样机到批量生产过程的流量计还绝无仅有。涡街流量计是一种流体振动式流量计，在流体中设置旋涡发生体（阻流体），从旋涡发生体两侧交替地产生有规律的旋涡，这种旋涡称为卡门涡街，旋涡列在旋涡发生体下游非对称地排列，涡街流量计通过测量其旋涡产生的频率而实现流量计量。涡街流量计由传感器和转换器两部分组成。传感器包括旋涡发生体（阻流体）、检测元件、仪表体等；转换器包括前置放大器、滤波整形电路、D/A转换电路、输出接口电路、端子、支架和防护罩等。近年来智能式流量计还把微处理器、显示通讯及其他功能模块亦装在转换器内。按检测方式划分，涡街流量计可分为应力式、电容式、热敏式、超声式、振动式、应