This paper presents a new order-based method, which has been developed to automatically identify resonances from operational data in an engine run-up. The method considers the run-up as a multi-sine sweep excitation and combines advanced Order Tracking with Operational Modal Analysis to identify the resonances.
A three-steps approach is used. In a first step, an automatic order detection algorithm is applied to identify the significant engine orders in the measured data. These significant orders are then accurately tracked in both amplitude and phase by using an advanced time-varying DFT Order Tracking method. Once this is achieved, the PolyMAX modal parameter estimation algorithm is applied to the tracked engine orders to identify the resonances.
The method is illustrated and discussed using the measured in-vehicle sound data and tacho pulse signal of a 4-cylinder car in run-up conditions. The obtained resonance identification results are compared with those of a more traditional, spectrum-based method for Operational Modal Analysis.
