Mechanical modeling and decoupling analysis of the large deformation six-axis force sensor based on sensing units

To improve the accuracy of the measurement and to minimize the coupling between the directions is the key to the research of large deformation six-axis force sensors with good compliance. Utilizing large-deformation six-axis force sensors for accurate monitoring of ground reaction forces (GRFs) during human locomotion is of great significance in the field of biomechanics and pathological gait diagnosis. The proposed flexible six-dimensional force sensor has a flexible optical waveguide-based sensing unit as the detection element to make it capable of detecting large deformations. Firstly, the design and mechanical modeling of the sensor were carried out, and the force information measurement of the corresponding channel was achieved by arranging the sensing unit with the centering position of the isotropic viewpoints, and at the same time simplifying the solution of the hyperstatic structure. Secondly, by adopting a split structure, a complete mechanical decoupling can be realized in theory. The designed measurement scales are Fx, Fy = 0-160 N, Fz = 0-800 N, Tx, Ty, Tz = 0-20 Nm, which satisfy the requirement of monitoring the ground reaction force information when human body is in motion for wearable devices.