Vibration acceleration control of an inverter-fed electrodynamic shaker

Concerns control of an electrodynamic shaker for vibration-proof testing of electronic products. An acceleration controller for such a shaker fed by a switching-mode power amplifier is presented in this paper. First, the dynamic model of the shaker system is found and a high-performance current-controlled pulsewidth modulated inverter is designed and implemented. Then, a sophisticated acceleration control scheme being capable of waveform and magnitude regulation controls is proposed to lessen the undesired harmonic vibration caused by switching-mode driven power. In acceleration waveform control, the feedback controller is augmented with a feedforward controller and robust controller for obtaining excellent waveform tracking performance over a wide frequency range. As to the magnitude regulation control, the amplitude of the sinusoidal acceleration is accurately controlled to be equal to the setting value. Theoretical basis, practical consideration, and implementation of the proposed controllers are described in detail. Good current and acceleration control characteristics of the designed shaker are demonstrated by some measured results.