Feature identification in the time–frequency plane by using the Hough–Radon transform

摘要

We propose a novel approach to detect frequency-modulated (FM) components such as chirp, sinusoidal FM, and hyperbolic FM components in multicomponent, nonstationary signals by application of pattern recognition techniques in the time–frequency (TF) plane. The approach, based upon the use of a combined Hough and Radon transform (HRT) can be used to detect FM components with varying energy and duration. The HRT method uses an array of accumulators, and the quantization of the array bins makes the method flexible and computationally attractive. Results with synthetic signals and a real-world signal (knee-joint vibration signal) indicate the potential of the method in identifying the components in noisy environments. The HRT method could be extended to detect components generated by any FM law provided they can be modeled by parametric equations.