A variable step-size adaptive notch filter for frequency estimation using combined gradient algorithm

Abstract

To improve the performance of adaptive notch filter (ANF), a variable step-size ANF using combined gradient algorithm is proposed for frequency estimation. In this method, combined gradient algorithm is designed for improving constringency with both FIR-ANF and IIR-ANF advantages considered. According to the noise influence, a bias correction strategy is established for depressing the bias and MSE of frequency estimation. Additionally, variable step-size is adopted for the balance of convergence and precision. The proposed method process is given. In simulations, we discussed the influence of the ANF parameters and SNR on accuracy. Algorithms of DPG and MPG are carried out as comparisons. Convergences of these methods are also analyzed. Coriolis mass flow meter (CMF) is taken as an application to test the proposed method. Simulation results and CMF application both confirm the availability and superiority of the proposed method.