Identification and retuning of optimum delayed feedback vibration absorber

A recursive system identification and retuning methodology is presented for a recently developed delayed feedback vibration absorber. The retuning is needed against the parametric variations in the system. It is performed to maintain optimal vibration suppression properties for wideband excitations. The optimized absorber offers minimum peak frequency response within the given wideband frequency range. A new scheme is introduced for the tuning of the absorber as the system experiences structural variations. The scheme suggests a nested procedure of two optimization steps, one for identification and the other for control, Feasibility of the proposed methodology is demonstrated through simulations. One of the examples deals with a single-degree-of-freedom system, and the second one is for a two-degree-of-freedom setting. Results show that with only three iterations used for the first example and five iterations used for the second example in the parameter identification part of the process, the frequency response peaks are reduced by 25%.