Related Ultrasonic Flowmeter In The Hardware Implementation

Both industrial production and scientific experimentation cannot go away with realization and control of flow. The ultrasonic flowmeter's operating theory is that when ultrasonic pass the liquid,it carries out the signal reflecting the liquid's flow velocity,and then,the signal will be used to compute the flow. Due to its advantage in accuracy,turndown ratio and no excess pressure drop,the current market for ultrasonic flow meter technology is growing rapidly in flow measurement. Ultrasonic cross-correlation flowmeter with high accuracy and large measurement is one of the key researches. As its name, ultrasonic cross-correlation flowmeter finish the measurement by testing the cross-correlation between two signals which come from the same pipe. There are several ways to compute correlation; however, it is done by the way of FFT and IFFT in this essay. With rapid development in recent years, FPGA has exceeded DSP in dealing high speed easy attempter data. We use FPGA instead of DSP in the project.From the actuality of ultrasonic flowmeter, the essay comes to introduce the principle of the ultrasonic cross-correlation flowmeter, which proves FFT (Fast Fourier Transform) necessary.This paper studies the implementation of FFT processor base on FPGA. It includes selection and validation of the arithmetic, design of the whole architecture and modules, implementation and test of the system. This design adopts the algorithm of radix-2 and decimation in time, and realizes a block-floating point FFT system of 512-point which is 16-bits complex number by using VHDL at the interface of QUARTUS6.0 provided by ALTERA .The correlator is built based on the FFT processor Then it finishes simulation and synthesis of the system and takes measurements on the STRATIX DSP development Board Rev1.1.