Research On Digital Processing Of Vortex Signals

Vortex flowmeter is widely used in liquid, gas and steam measurement in industrial production dueling to its numerous advantages. The advantages of the flowmeter, such as having no mechanical movable parts inside it, having wide adaptability to different medium, having little stress loss and frequency signals output all make it popular in industrial production. But still there are some faults. If it is used under small-rate of flow, vortex flow signal can be easily interference by noises, so when it is used in industrial spot, the issues such as the low accuracy in measuring results, narrow measuring scope and small-rate of flow measurement difficulties will appear. In order to effectively solve these issues, in this paper, vortex digital signals processing technology is studied.In this paper, the study background and significance are firstly clarified, and then vortex flowmeter working principles and vortex signals characteristics are introduced in detail. After these, the present study situation both at home and abroad are given in order to know the study better. Then, the paper bring up a new proposal to do vortex signals processing, that is to process the signals in frequency domain and time domain simultaneous, and use the results of frequency domain signal processing to initialize the parameters used in time domain. In frequency domain, Fast Fourier Transform (FFT) spectrum analysis and FFT correction algorithm and still a new algorithm based on energy of vortex flow signal are used to get vortex flow signal. With the aim to improve the system efficiency, circular linked list is used to realize circulation data storage. In time domain, a method to use overlapping digital filters to realize vortex flow signal real-time tracking is brought up. The method adopts digital signal processing technology to design overlapping digital band-pass filters, by using the filters, vortex flow signals can be separated from the noises on real-time.To test whether the algorithm mentioned are helpful or not in vortex signal processing, Visual C++ 6.0 software developing platform on PC is used to compiling computer language C,The test results show using the algorithm mentioned, to some extent, can help to make it possible to achieve accurate measurement under small-rate of flow by increasing measurement accuracy and broadening the measuring scope.