自适应陷波滤波器(ANF)对科氏流量计信号频率的持续跟踪精度不高。综合基于Steiglitz-Mcbride系统辨识方法(SMM)的新式ANF收敛速度快和变步长直接频率估计(VS-DFE)计算量小的优势,提出一种两者交替工作的科氏流量计频率跟踪方法。给出了该方法基本思想、原理分析和实现步骤,实验分析了其主要性能。结果表明,该方法兼具新式ANF收敛速度快、短时频率跟踪精度高和VS-DFE持续跟踪频率缓变能力强的特点,比常用的格型ANF方法收敛速度快、跟踪精度高,比单一采用新式ANF计算更为简便、持续跟踪能力更好。
Adaptive notch filters(ANF) cannot continuously and precisely track the frequency of CMF(Coriolis mass flowmeter).Considering the fast convergence speed of SMM(Steiglitz-Mcbride method) based new ANF(the new ANF) and the little computation of VS-DFE(variable step-size direct frequency estimator),a frequency tracking method for CMF is proposed,in which the new ANF and VS-DFE work by turns.The basic notion,principles and detailed process of this method are presented.Moreover,its performances are also analyzed by simulations.The results illuminate that the presented method assimilates the characters of the new ANF and VS-DFE.It has also been confirmed that the proposed method has the advantages of convergence,higher long-playing tracking accuracy than the lattice-based ANF and the SMM-based ANF.