新DFT递推算法在涡街流量信号处理中的应用

New recursive DFT algorithm and its application in signal processing of vortex flowmeter

采用压电传感器的涡街流量计在测量中容易受到工业测量现场管道振动和流体振动引起的噪声干扰,传统信号处理电路不能保证仪表在工业现场的测量精度.利用三角函数的和差公式,推导了一种新的DFT递推算法,用于计算涡街信号的功率谱,通过谱分析得到涡街频率.实验表明,这种方法用于处理涡街流量信号具有算法简单,计算量小,实时性好,实现方便等特点,能有效抵抗噪声,提高测量精度,是一种新的涡街流量信号处理方法,具有很好的实用价值.

The vortex flowmeter based on piezoelectric transducer is subjected to noise disturbances caused by pipe vibrations and fluid turbulence during measurement. The traditional processing circuits in vortex flowmeter cannot ensure the measuring accuracy in industrial fields. A new recursive Discrete Fourier Transform (DFT) algorithm based on the sum-and-difference formula of trigonometric function is introduced. It can be used in the calculation of vortex signal power spectrum by which the vortex frequency is obtained. The proposed method is comparatively simple, highly efficient, real timing and convenient to realize, and being suitable for vortex signals. The experimental results proved that this method had strong anti-noise ability, high efficiency and broad application prospects.