Wavelet Transform Based Digital Signal Processing Method And System For Flowmeters Of Flow Vibration Principle

The flowmeters based on the principle of flow vibration are widely used. However, they are easily subjected to noises caused by pipe vibrations and fluid turbulence. The analogy circuits in flowmeter are unable to ensure the measuring precision of flowmeters in fields, and make the span ratio of flowmeter lower than theoretical value. Therefore the output signal of flow sensor is processed by means of the wavelet transformation to calculate the accuracy frequency in this paper. A digital signal processing system is developed for flowmeters with DSP and CPLD. The hardware in this system includes a digital signal processor, an analogy input channel, a LCD, an analogy output path, a keyboard input part, a guard circuit and a logic control circuit. The software in this system includes a monitor program, a LCD display program, an interrupt service program, a computing program and so on. The whole software is developed by C language, and is easy to be read and migrated. The system processes the signal in real time, and ensures the measuring precision.