超声和激光结合的实时在线测流技术研究

发布时间：2018-03-02 08:19

本文关键词： 超声激光测流快速傅里叶变换 FPGA RS485 LCD1602　出处：《南京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：本课题旨在对超声波和激光结合的实时在线测流技术进行研究,对超声测流技术中的实测线速度和线平均速度的关系进行了推导论证,对超声测流和激光测流的优缺点进行了分析,设计了超声测流和激光测流结合的总体实现方案,同时提出了对测流信号进行信号处理的方案。在总体方案确定的基础上进行一些器件的选型,设计了超声波收发电路,实现了超声测流部分的AD转换电路,设计了光电信号转换电路,在FPGA上实现了驱动超声发射电路的DDS数字信号发生器,实现了基于FPGA的激光多普勒测流信号的FFT处理模块和基于FPGA的超声测流信号预处理的FIR数字滤波器,实现了基于FPGA的LCD显示模块和基于FPGA的RS485串口通信模块以实现在线功能,设计了RS485接口电路。通过实验验证了业已实现的超声测流部分的AD转换电路的功能,分别测试了基于IP核的1024点FFT和不基于IP核的16点FFT的分辨频率的功能,通过和上位机的通信验证了基于FPGA的RS485的串口通信协议。
[Abstract]:The purpose of this paper is to study the real-time on-line flow measurement technology combined with ultrasonic and laser, and to deduce and demonstrate the relationship between the measured line velocity and the line average velocity in the ultrasonic current measurement technology. The advantages and disadvantages of ultrasonic flow measurement and laser current measurement are analyzed, and the overall scheme of combining ultrasonic current measurement with laser current measurement is designed. At the same time, the scheme of signal processing for current measurement signal is put forward. On the basis of the determination of the overall scheme, some devices are selected, the ultrasonic transceiver circuit is designed, and the AD conversion circuit of ultrasonic current measurement part is realized. The photoelectric signal conversion circuit is designed, and the DDS digital signal generator which drives the ultrasonic transmitting circuit is realized on FPGA. The FFT processing module of laser Doppler current measurement signal based on FPGA and the FIR digital filter of ultrasonic current measurement signal preprocessing based on FPGA are implemented. The LCD display module based on FPGA and the RS485 serial port communication module based on FPGA are realized to realize the on-line function. The RS485 interface circuit is designed, and the function of AD conversion circuit of ultrasonic current measurement is verified by experiments. The function of resolving frequency of 1024-point FFT based on IP core and 16:00 FFT without IP core is tested, respectively. The serial communication protocol of RS485 based on FPGA is verified by communication with host computer.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB559;TN249

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