High-Precision Positioning with Strain Feedback Using Piezoelectric Element

Abstract

This paper presents a novel control methodology for robust high-precision positioning systems. This methodology is based strain feedback using a piezoelectric element. The mechanical vibration modes at around the control bandwidth cause the deterioration of system stability. This prevents the positioning performance from being robust, particularly against variations in the vibration frequency. In this research, therefore, a robust positioning system was designed by applying an additional compensation loop by strain feedback; here, a piezoelectric element that acts as a strain sensor detects the vibration signal. This makes the performance of the system robust. The proposed compensation approach has been verified by numerical analyses and by experiments using a positioning device for industrial galvano scanners.