GelStereo Palm: A Novel Curved Visuotactile Sensor for 3-D Geometry Sensing

Recently, visuotactile sensors have shown promising potential in robotics due to their high-resolution sensing ability. Unfortunately, the majority of available visuotactile sensors are limited to flat shapes, which severely limits their application possibilities. In this article, we propose a novel curved visuotactile sensor, the GelStereo Palm, which senses the 3-D contact geometry on a curved surface using a binocular vision system. Meanwhile, to solve the light refraction problem in the binocular stereo vision system under a curved medium, a refractive stereo ray tracing model for GelStereo Palm is presented. Moreover, a 3-D tactile point cloud sensing pipeline is introduced to reconstruct the 3-D contact geometry in real-time. Finally, extensive experiments are conducted to verify the accuracy and robustness of the 3-D contact geometry sensing of our GelStereo Palm sensor.