A vision-based tactile sensor with single contact surface for pressure and slippage estimation

Abstract

Touch is an important way that a human being senses the surrounding environment, but in robotic applications, it is difficult to obtain static and dynamic tactile signals simultaneously. In this paper, we proposed a new vison-based tactile sensor to estimate pressure and slippage distance at the same time. The sensor recognizes the deformation degree of elastomer through image processing, and the pressure is estimated according to the radius of contact region. Sensor captures the surface of the contact object and tracks feature point to calculate optical flow. Then the slippage distance is estimated by Kalman filtering and integration of the optical flow. The sensor is realized in a small package, so it can be useful in wide range of scenarios. Here we also built a two-dimensional experimental platform to test the sensor, and the experimental results show that the average error of pressure estimation is 6.4%, and the average error of slippage estimation is 14.4% at 5mm/s, demonstrating a good sensing performance for providing pressure and slippage via the single contact surface.