Fuzzy Control Of A Vibration Actuator

A fuzzy logic based digital sinusoidal acceleration waveform amplitude controller for a PC based electrodynamic vibration actuator is presented. The fuzzy logic control (FLC) purpose is to reproduce pre-defined sinusoidal acceleration amplitude at the vibration table of a vibration actuator system. Sinusoid vibration profiles (sine and linear sine sweep) are considered for a closed-loop controlled vibration generation for rigid load. The difficulty in sine vibration generation is the unmodeled and complex non-linear dynamics of the vibration actuator system. To cater to the needs of a sine sweep vibration generation, the controller needs to be robust to un-modeled dynamics of the vibration actuator system as well as sufficiently fast to hold the specified acceleration amplitude. The performance of the developed control logic is tested in real time using LabVIEW based virtual instrumentation (VI) tools for vibration signal acquisition and measurement on the in-house designed and developed prototype shaker system for reference tracking and disturbance rejection. The performance of the proposed solution is also compared to a classical conventional Proportional and Integral (PI) control. FLC is found to be faster and more robust to un-modeled dynamics of the shaker system. Furthermore, the implemented approach is simple, straight forward and free from the un-modeled and complex dynamics of the vibration actuator system. The actuator design, FLC synthesis, implementation and comparative study with a PI controller in real time are presented in this paper.