In-Place Calibration for Coupling Error of Six-axis Dynamometer Based on Fiber Bragg Grating
Different from strain gauge dynamometers,six-axis dynamometer based on fiber Bragg grating(FBG)adopts the structural force measurement principle,and one of its main performance parameters is the coupling error.Due to the limitation of its application scenario,in-place calibration is usually performed.The sensing structure and principle of the FBG six-axis dynamometer are analyzed,and an in-place calibration device without a standard force source is proposed according to the coupling error model.An in-place calibration method based on a robot arm for coupling error is also established,in which the calibration process is simplified and the source of uncertainty is reduced.The uncertainty of calibration results is analyzed with a practical example,and the effectiveness of the method is verified.