Novel contactless Hybrid Static Magnetostrictive Force-Torque (CHSMFT) sensor using Galfenol

Abstract

This paper presents a novel Contactless Hybrid Static Magnetostrictive Force-Torque (CHSMFT) sensor using Galfenol. Initially, the sensor's design principles for measuring axial force and torque are outlined. The magneto-mechanical properties of the materials used, such as B-H curves and magnetic permeability, are determined and used in the finite element method when various mechanical preloads and magnetic fields are applied. The CHSMFT sensor is evaluated analytically using the equivalent circuit method and numerically using COMSOL Multiphysics® software based on the obtained experimental results. Afterward, the sensor is fabricated based on the results of the analytical and finite element method and experimentally validated for a range of electrical currents and excitation frequencies. The analytical and finite element method results are then compared to the experimental results. In force and torque measurements, sensitivity, precision, and linearity error are presented separately. Finally, the CHSMFT sensor's performance characteristics under optimal conditions are presented. Sensitivity is found to increase with rising electrical current (or magnetic field) and frequency. Maximum sensitivities are obtained at 0.7349 mV/kgf and 2.24 mV/Nm for axial load and torque measurements, respectively.