Realization of Cross-Correlation Algorithm Based on Lightweight Design in Ultrasonic Flowmeter

Time-difference ultrasonic flowmeter is widely used in industrial measurement, the level of flow detection is closely related to industrial development, energy saving, economic construction and scientific research. In order to improve the precision and anti-interference ability of the instrument, the high-speed analog-to-digital converter is used to sample the echo signals received from upstream and downstream respectively to obtain the primitive discrete echo signals in time-domain. The cross-correlation algorithm is optimized by using Fast Fourier Transform (FFT) and Fast Fourier Inverse Transform (IFFT), and the measurement accuracy is improved by cubic spline interpolation. The maximum point of the cross-correlation function corresponds to the time shift, that is, the time-of-flight (ToF) difference. The lightweight cross-correlation algorithm proposed in this paper not only improves the anti-noise ability, accuracy and stability of ultrasonic flowmeter, but also greatly reduces the amount of calculation and improves the operating efficiency of micro-controller so that it can be deployed into embedded devices.