Design Of Multi-path Ultrasonic Flowmeter Based On DSP

As one of the three parameters in industrial automation, flow has become anindispensable part in industrial production. Ultrasonic flowmeter has the advantages of highmeasuring precision, high stability, non-contact measurement, easy installation and nopressure loss. It has great significance to study the ultrasonic measurement technology.Several measurement principles of ultrasonic flowmeter and principle of multi-pathlayout and channel weighted calculation have been studied. Measurement scheme choosestime difference method and the parallel arrangement of multi-path layout. By theGauss-Legendre numerical integration method, track position parameter and weightingcoefficients are determined. It enhances measuring accuracy, and improves theanti-jamming ability of flowmeter in flow velocity fluctuations.The overall design of hardware system has been given, the DSP peripheral interfacecircuit, the ultrasonic transmitter and receiver circuits and channel switching circuit havebeen designed, the working principle of multi-path ultrasonic flowmeter has been explained,the specific implementation method of determining transmission time and the timedifference has been clarified, and multi-path weighted algorithm has been analyzed.Following the analysis of the basic principles of signal spectrum analysis using FFTand FIR digital filter and the simulation of their methods, the on-chip resources andprogramming methods of TMS320F28335are introduced. Using TMS320F28335as a corecontrol chip，1MHZ multiple pulse square wave as an excitation and the threshold methodto determine signal arrival time, the pipeline flow measurement system has been designed.By the time delay compensation and channel compensation, the measurement precision offlowmeter is further improved.The core measure algorithms have been simulated by MATLAB, the hydrostatic fluidtest in the actual pipeline has been done, and the on-chip resources of TMS320F28335havebeen fully used; the results show that the design simplifies system hardware design, and hasa better anti-jamming performance, with higher dynamic response and improved accuracy.