EXPERIMENTAL INVESTIGATIONS ON FLEXURALLY AMPLIFIED PIEZOACTUATOR BASED ACTIVE VIBRATION ISOLATION SYSTEM USING PID CONTROLLER

This paper presents the development and implementation of a closed loop proportional integral derivative (PID) control system on a flexurally amplified piezoactuator-based active vibration isolation setup. The vibration isolation system is designed to control the vibrations of work piece during micromilling. The proposed setup uses two flexurally amplified piezoactuators (FAPs) where FAP1 is used to generate the vibrations and FAP2 is used to nullify the vibrations generated by FAP1. Flexural amplifiers are used to amplify the displacement of piezostack actuators. The nonlinear hysteresis behaviour of FAPs is identified using experimental voltage displacement plots and is modelled using Forward Bouc-Wen hysteresis model. The voltage to be applied for hysteresis compensation of FAPs is estimated using Inverse Bouc-Wen model. The linear inverse model of FAP2 is identified using its known parameters and is implemented in the proposed closed loop control system to estimate the control voltage to be supplied to FAP2 corresponding to control displacement obtained by tuning PID gains for nullifying the vibrations generated due to FAP1. Active vibration isolation experiments are carried out using dSPACE for 200 itm vibration amplitude at 1 Hz frequency, and percentage error in vibration isolation is estimated.