Instantaneous frequency estimation and order tracking based on Kalman filters

Order tracking (OT) is a signal processing technique that allows capturing the dynamics of the vibration signals measured from rotating machines. In this paper, its propose an OT scheme based on extended Kalman filter (EKF), which comprises the advantages of existing OT techniques. Proposed scheme allows estimation of different spectral/order components of the signal and, in addition, estimates the shaft speed, improving the reconstruction of the different waveforms of each particular harmonic component. A comparison with the VoldKalman filtering (VKF) scheme is developed using two synthetic signals, to determine the noise sensibility and the ability to separate close order components. Results show that EKF scheme successfully characterizes close order components, improving the outcomes of the VKF scheme reducing the waveform reconstruction error of each spectral component. Additionally, the estimation of the reference speed of the shaft has good performance compared with the signal original frequency.