Tomographic Approach for Universal Tactile Imaging With Electromechanically Coupled Conductors

In this paper, we propose a novel, low-cost, and universal tactile sensing technology for imaging pressure distribution using a tomographic approach with conductors. In particular, we focus on the fact that pressure is related to the contact resistance between two conductive objects. The sensor comprises driving and probing conductors, which are electromechanically coupled. The system solves an inverse problem for estimating electrical boundary conditions using the voltage sets from electrodes on the border of the probing conductor. The sensing system successfully estimates the pressure distribution, contact location (error rate: 5.68 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 2.78%), and local pressure (error in the range 0.0269 <inline-formula><tex-math notation="LaTeX">$ -$</tex-math></inline-formula>0.0509 N/mm<inline-formula><tex-math notation="LaTeX">$^2$</tex-math></inline-formula> for a maximum pressure of 0.50 N/mm<inline-formula><tex-math notation="LaTeX">$^2$</tex-math></inline-formula>). Finally, tactile imaging by sheet- and finger-type sensors are demonstrated as practical applications of the developed sensor.