【作者】 杨扬；

【导师】 王时胜；

【作者基本信息】 南昌大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 超声波流量计是最近发展很迅速的一种流量计量计,有着突出的优势,在工业生产,医疗检测,海洋观测,石油勘探等社会生产生活诸多领域有着广泛的应用。国内外的厂商有众多产品问世。然而,由于实地现场的不同和应用情况的复杂,超声波流量计在提高环境的适用性、便携性、稳定性以及改进测量的精度等等方面,还有很多有待进一步研究深化的地方。本文首先查阅了大量国内外流量计产品基本性能,对超声波流量计基本原理和进行了分析总结,介绍了几种常见的方法,并在此基础上提出了改进的思想;采用以DSP为信号处理核心,以FPGA器件为控制核心,辅以前端模拟电路,以FFT为主要算法的多普勒效应法的超声波流量计的设计方案。本文完成了整体硬件电路的设计,这其中包括模拟电路方面的超声波的发射、接收、滤波、三级放大和采样,数字电路方面的DSP、FIFO数据缓存、单片机硬件系统的设计以及CPLD的时序控制设计。软件方面完成了CPLD程序的设计,实现了DSP和单片机硬件系统的完整性;完成了DSP在流速计算方面的程序的设计,这其中包括滤波、插值、FFT的软件设计。并对关键的算法用matlab、Simulator、CosmosScope等软件进行了仿真。更多还原

【Abstract】 The Ultrasonic Flowmeter is one kind of flowmeter which has been developed rapidly recently. It has many advantages and has been widely used in social production and social life, such as manufacturing production, medical treatment, oceanographic observation, Oil exploration and so on many realm. There are plenty of Series Products have been developed in home and abroad. But, to different application areas and situations, further research in this area is required in order to improve the environmental Sustainability, portability, stability and measurement accuracy of the Ultrasonic Flowmeter.In this paper, we first studied lots of Product Information of foreign Ultrasonic Flowmeter products, researched on their fundamental characteristics, and summed up the fundamental principle of Ultrasonic Flowmeter; then, some approaches of making Ultrasonic Flowmeter was introduced, and the innovative approach was put forward based on these researches-new design of Ultrasonic Flowmeter based on Doppler Effect Method. In this design, DSP was the signal processing core; CPLD was the control core; besides, there is also Front Analog Circuitry; the main algorithm is Fast Fourier Transform.In the paper, we finished both the hardware design and software design of Ultrasonic Flowmeter. The hardware was consists of analog circuit and digital circuit. The analog circuit includes ultrasonic transmitting, receiving, three stage amplifying and sample circuit. The digital circuit includes the design of DSP, FIFO and the single chip system, and the design of CPLD sequential control. The software of Ultrasonic Flowmeter includes CPLD programming, DSP programming used in calculating velocity of flow, and MCU program module. The whole software system was fully realized which includes the software design of filtering, interpolation, Fast Fourier Transform. The key algorithm of the whole system has been simulated by matlab, matlabSimulator, CosmosScope and so on.更多还原