Theoretical and experimental research of six-dimensional force / moment measurement piezoelectric dynamometer

Abstract

High-accuracy measurement for force is essential in the Robotics design, Rocket thrust, manufacturing process, and biomedical equipment. To realize the multi-dimensional force/moment measurement, a multi-points force / moment measurement piezoelectric dynamometer capable of measuring spatial force information has been developed. The experimental prototype dynamometer is fabricated according to the designed numerical simulation model (Finite element method: FEM) in which eight three-axis piezoelectric sensors are uniformly distributed in a zigzag pattern. The constructed dynamometer is calibrated both statically and dynamically, static calibration is carried out using a manual hydraulic loader, and the dynamic calibration is performed by impact load technique. The maximum error difference between the theoretical simulations and experimental analyses is approximately 7%. The experimental calibrated results evaluate that the cross-talk error of the applied axile force, normal force and pitch moment is less than 4% and the natural frequency  of the dynamometer in each coordinate is greater than 0.35 kHz.