基于DSP的科氏流量计变送器设计及算法验证

Design and algorithm verification for DSP-Based CMF transmitter

科氏流量计已在很多领域得到广泛应用,但仍存在着精度较低、价格高昂、技术垄断等问题,而科氏流量计的关键在于变送器。为此,提出了一种变送器设计方案,分别从功能、硬件和软件等方面进行阐述,实现了一种基于改进的自适应格型陷波器和重叠短汉宁窗滑动DTFT的信号处理方法。通过测频和测相实验,与DFT法进行了比较分析;通过流量测量实验,与某款国产变送器进行了比较分析。实验表明,自制流量计精度有所提高,实时性良好,频率估计误差在0.02‰以内,相位差估计误差在0.8‰以内,流量测量误差在1.8‰以内,能在0.96 ms内给出测量结果。

Coriolis mass flowmeter is used in many applications , but it still has many drawbacks , such as low accu-racy, high expense, technological monopoly, etc.The key of Coriolis mass flowmeter is its transmitter.In order to solve the problems, a transmitter design scheme was proposed from the functional, hardware and software aspects respectively.A CMF signal processing method based on Modified Adaptive Lattice Notch Filter and Sliding DTFT with Overlap Hanning Windows was implemented .The method was compared with DFT algorithm via the frequency and phase difference estimation experiments.Subsequently, the transmitter was compared with the other Chinese one on the experimental platform via the flow measurement experiment .The result indicates that the self-designed transmitter has a higher accuracy, and the error of frequency estimation is less than 0.02‰, the error of phase esti-mation less than 0.8‰, the error of flow measurement less than 1.8‰, and the measurement can be acquired in 0.96ms.