High-accuracy calibration method based on piezoelectric dynamometer for large vector force

Abstract

ABSTRACT High-accuracy measurement for vector force is essential in the process of industrial manufacture and control. Piezoelectric sensor has the characteristics of high frequency and stiffness, great dynamic response and resistance to harsh conditions, which are widely used to measure vector force. To solve the problem that vector force calibration device (VFCD) is difficult to comprehensively calibrate vector force test system (VFTS), a multi-station calibration method is proposed. Taking the six degree-of-freedom of vertical large VFCD as an example, mechanical model of vector force is established after matching output voltage and force value of piezoelectric dynamometer. Multi-station deflection calibration experiment is performed, and a fitting circle method is proposed to fit vector force parameters of multi-station under different step-force loadings. Finally, the results show that error of multi-station vector force calibration is less than 2%, which proves rationality of the calibration method. The error of fitting radius obtained by fitting circle method is less than 3.4%, which further verifies reliability of the calibration method, and provides a guarantee for VFTS to accurately measure vector force.