DETECTION OF THE VORTEX SIGNAL IN VIBRATION ENVIRONMENT AND SIGNAL PROCESSING BASED ON EMD DECOMPOSITIONS

The vortex signal is greatly disturbed by noises from pipe vibration, which results in difficulties of using vortex flowmeter in vibration environment. In order to solve the problem, a new method of anti-cyclical vibration for vortex flowmeter is proposed in this paper, which aims to eliminate the vibration of the vortex flowmeter via detecting vibration signal. The main frequency component of pipe vibration signal is analyzed by using EMD method and the energy method based on IMF. Then the main frequency component is chosen as a notch filter. Subsequently, a true vortex signal is gained via filtering the complex vortex signal in the frequency domain. Through experimental measurement of gas flow under different acceleration and directions of vibration, a better linearity of measurement is achieved by the proposed method in vibration environment.