In Situ Calibration of a Six-Axis FBG Force/Moment Sensor for Surgical Robot

Abstract

This paper developed a layered six-axis FBG force/moment sensor to measure the force/moment during robot-assisted bone drilling. The design that eight unique C-shaped beams form a layered elastic structure and eight FBGs are mounted on the structure to sense six-axis force/moment, leads to low chirping risk and low fabrication cost. An in situ calibration method done with a robot and standard weight has been proposed to calibrate the designed sensor and overcome the performance degradation caused by installing and removing sensors. The calibration results that the sensor has excellent measurement accuracy with a relative error of 6.92%. A robot-assisted bone drilling test has been implemented to further prove the potential application of the proposed sensor and the in situ calibration method for high-precision Force/Moment measurement in surgical robots.