Stiffness modeling and force mapping analysis of hybrid-limb six-axis force sensor

To meet the needs of large load and high reliability measurement under complex working conditions and downsize the outline of six-axis force sensor as much as possible, the design concept of hybrid limb is proposed to the design of parallel six-axis force sensor. A kind of heavy-load-bearing flexible integrated six-axis force sensor with hybrid limbs is proposed. The proposed force sensor adopts a hybrid-limb configuration integrating eight measuring redundant limbs and four load-bearing limbs. It is capable of measuring 5500 N vertical force, 3000 N horizontal force, 160 N center dot m moment about the vertical axis, and 130 N center dot m moment about the horizontal axis. Based on the superposition principle under small deformation, the whole stiffness matrix of force sensor and the analytical mapping relation are constructed, respectively. The accuracy of the theoretical modeling is verified by the stress analysis of the designed sensor using finite element method software ANSYS. Finally, the prototype is calibrated, and the results show that it has good linearity.