Acceleration Control of an Inverter-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 good acceleration reference tracking performance and robustness in the closed loop control from 20 Hz to 1 kHz