Study Of Fluid Velocity Sysytem Base On DSP

Non-contact velocity measurement system has the advantage of simple, safe installation,and high measurement accuracy. It is widely used in Hydraulic system. It gradually replacesthe traditional monitoring equipment. It developed with the processing of radar technologyand digital signal processing. It plays an important role in the Hydraulic system.This system mainly utilizes radar technology and DSP signal processing technology. Thefluid velocity measurement method is processing the Doppler echo signal of electromagneticwave.The principle of the fluid velocity measurement by electromagnetic wave is based on theDoppler Effect. The velocity is calculated by detecting the echo signal which has theDoppler frequency shifts. And digital signal processing technology is to improvemeasurement accuracy.The method of processing the echo signal is implanting spectral estimation algorithm inthe DSP system. It is important to select the appropriate spectral estimation algorithm. Thispaper describes FFT. FFT is a common method in spectrum estimation. But FFT algorithmhas unavoidable issues---spectrum leakage. And several FFT improvement algorithm andfive kinds of discrete spectrum analysis correction methods is introduced, including: theratio correction method, the center of gravity of energy correction method, FFT+FTcontinuous zoom FFT analysis correction method, the phase correction method and the phase+FT spectrum correction method.In the hardware, firstly, this paper introduces the hardware design of the system, thevarious parts and the section of chip. The factors of the chip selection are including chipfeatures, technical parameter selection, the effect that can be achieved, as well as the price ofchips.In the software, the paper introduces the development and the characteristics of the signalprocessing chip—DSP, the application of the resource on-chip. The paper fully introduces the process of the whole system and the mainly algorithm analysis, such as sub-samplingalgorithm, data collection, etc. And it introduces the method of optimization setting in thesoftware.The paper simulates and analyzes the signal by using FFT and refining method, and setsof data are compared. The appropriate estimation method is selected. Program is implantedinto the DSP chip. The whole system is produced, and it is tested. The experiment includesthe measurement in zero velocity and in the sink water velocity, and the analysis of the data.