动态多频数字锁相算法及其应用

Dynamic Multi-frequency Digital Lock-in Algorithm and Its Application

该文提出一种动态多频锁相算法。与传统锁相方法相比,该算法不需要选择参考信号的类型,在继承了传统锁相方法高信噪比优点的基础上,能够锁出由一个基频和多个倍频分量合成的复合信号的幅值,从而获得更多的有用信息。同时,采用动态调整参考信号频率的方法,有效地解决了实际信号频率漂移引起的幅值求取误差问题。应用于NDIR红外气体浓度检测的结果表明,该算法可以增大检测量程,并提高系统检测灵敏度。

A dynamic multi-frequency digital lock-in algorithm is presented in this paper. By this algorithm, the amplitude of the signal composed of the fundamental and the harmonics can be obtained. And in addition, the problem of frequency drift is solved by rectifying the reference frequency dynamically. Compared with the traditional method, this novel algorithm uses more information and does not need to choose the reference signal. When applied to NDIR gas concentration measurement, it not only widens the measurement range, but also improves the sensitivity of the detection.