Integral resonant control for suppression of resonance in piezoelectric micro-actuator used in precision servomechanism

Micro-actuators are widely used nowadays in mechatronic systems that demand ultra-fine precision and accuracy in positioning the object to be controlled. A large bandwidth is required as well to achieve such performance. The resonant modes of the micro-actuator would be one of the major obstacles in the path to achieving such a necessary high bandwidth. The servo designer must have the resonant vibrations suppressed in order to set the necessary bandwidth target sufficiently high so that the necessary precision requirements are met. The conventional approach is to use a notch filter in cascade with the actuator to provide high attenuation at frequencies of these resonances. In this paper, we present an improved alternative approach using a feedback compensator, designed based on the principle of ‘integral resonant control’, for attenuating resonances of a piezoelectric micro-actuator. Here, the effectiveness of the design is underscored through simulation and experimental verification.