Spectral Angular Speed Estimator (SASE): A Novel Algorithm for the Direct Estimation of Instantaneous Angular Speed Based on Vibration Signatures

Introduction: In the field of condition monitoring of rotating machines, the estimation of the Instantaneous Angular Speed (IAS) has emerged as a central element. The ability to accurately monitor the rotational speed of a system is a key element of many vibration-based condition monitoring methods. Information on rotational speed is essential to counteract potential speed fluctuations that could otherwise compromise the effectiveness of conventional frequency-based approaches. In practice, the installation of encoders or tachometers may not be possible or cost-effective. Therefore, the challenge of estimating IAS directly from vibration signals has attracted much attention in recent years. Objective: In this study, an innovative method for estimating IAS directly from a vibration signal is presented. Method: The new method is suitable for non-stationary speeds and can be applied to any speed range and rate of change. It requires only the basic system parameters as input. Results: The algorithm was verified and validated with simulated and experimental data. These simulations and experimental resultss allowed the verification of the proposed algorithm by calculating the root-mean-square errors between the estimated IAS and the simulated and measured speeds in all scenarios. The observed low maximum error shows the high accuracy of the algorithm. Conclusions: The strength of this method lies in its ability to correlate several characteristic frequencies of the rotating components of the system, which increases its robustness.