2nd International Conference of Engineering Against Fracture (ICEAF II), Mykonos,, Greece, 22 June 2011 - 24 June 2017, pp.1-8
In this study, a fractional order controller was designed and experimentally applied for the active vibration suppression of a smart beam. The smart beam was a cantilever aluminium beam equipped with eight symmetrically located surface-bonded PZT (Lead-Zirconate-Titanate) patches which were used both as sensor and actuator. For this particular application, a group of PZT patches closed to the root of the beam was used as actuators in the bimorph configuration and a single patch was nominated as a sensor. Fractional order controllers were known to provide better flexibility in adjusting the gain and phase characteristics than their integer-order counterparts. In the design of the controller, first, the fractional order differential effect was considered by using a fourth degree approach of continued fraction expansion (CFE) method. Then a filter was designed to characterize the dynamic properties of the smart beam in the first flexural mode. Finally, the controller was obtained by filtering the aforementioned differential effect. In order to evaluate the closed-loop frequency domain performances, the simulations were performed on various fractional orders of the differential effect and a controller was then selected for the experimental verifications. The obtained time domain responses have shown that the fractional order controller successfully suppressed the vibration levels of the first flexural mode of the smart beam.