Vibration Acceleration Control of an AC Power Source-Fed Electrodynamic Shaker

This paper presents the development of a novel digital acceleration controller for sinusoidal vibration tests using switching-mode AC power source (ACPS) fed electrodynamic vibration machines. The proposed scheme is based on the interaction of two control loops: one for the shaker´s acceleration regulation and another for the ACPS output voltage control. A robust model reference adaptive algorithm (RMRAC) is used in the voltage control loop. To reduce the effects caused by the plant´s parameters variations as well harmonic vibrations and resonances of the test specimen, the acceleration feedback controller is augmented with a feedforward and a robust controller. Experimental results show that the proposed system is capable to achieve excellent acceleration reference tracking performance and robustness in the closed loop control from 20 Hz to 200 Hz. Investigations shall be performed to evaluate the response of this scheme when controlling vibrations as fast as 2000 Hz