摘要
针对气体超声流量计信号处理中不易找到稳定的测量特征点的问题,提出了一种基于能量变化率的过零检测信号处理方法,以及最优阈值参数的选取方法。基于能量变化率的过零检测信号处理方法首先求取能量变化率曲线上的关键阈值点,然后回溯到原始波形信号上,找到对应的过零点,并以此作为信号的稳定特征点,进而求得信号的传播时间及气体流量。在以FPGA和DSP为核心的气体超声流量计信号处理系统上实时实现了算法,并进行标定实验,实验结果验证了方法的有效性。
Aiming at the problem that it is difficult to find stable feature point in the signal processing of ultrasonic gas flowmeter, a zero-crossing detection signal processing method based on the rate of energy and a method for determining the optimum threshold parameter are proposed. Firstly, this zero-crossing detection signal processing method obtains the key threshold point on the rate of energy curve, then traces back to the original waveform signal and obtains the correlated zero-crossing point, which is taken as the stable feature point of the signal. Finally, the propagation time of the ultrasonic signal is calculated and the gas flow rate is measured accurately. This method was implemented in real time in the signal processing system of the ultrasonic gas flowmeter with DSP and FPGA as the dual-cores, and calibration experiment was conducted. Gas flow calibration experiment resuhs verify the effectiveness of the proposed method.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2015年第9期2138-2144,共7页
Chinese Journal of Scientific Instrument
关键词
超声波
传播时间
能量变化率
过零检测
数字信号处理
ultrasonic
propagation time
rate of energy
zero-crossing detection
digital signal processing
