Order tracking by discrete Gabor expansion

In this paper, the discrete Gabor expansion is applied to order analysis-a special set of time-varying harmonic analysis. Here, the term orders, widely used in the automobile industry, refers to frequencies that are integer (or fractional) multiples of a single rotational speed. Since the rotational speed varies with time, the classical analysis techniques, such as harmonic analysis, cannot be directly used for order analysis. Compared to currently used techniques, such as the adaptive filter based approaches (e.g., Kalman filter), the method presented in this paper is not only more robust and easier to implement, but also offers more insight into the physical process.