Tactile sensing is a necessary capability for a robotic hand to perform fine manipulations and interact with the environment. Optical sensors are a promising solution for high-resolution contact estimation. Nevertheless, they are usually not easy to fabricate and require individual calibration in order to acquire sufficient accuracy. In this letter, we propose AllSight, an optical tactile sensor with a round 3D structure potentially designed for robotic in-hand manipulation tasks. AllSight is mostly 3D printed making it low-cost, modular, durable and in the size of a human thumb while with a large contact surface. We show the ability of AllSight to learn and estimate a full contact state, i.e., contact position, forces and torsion. With that, an experimental benchmark between various configurations of illumination and contact elastomers are provided. Furthermore, the robust design of AllSight provides it with a unique zero-shot capability such that a practitioner can fabricate the open-source design and have a ready-to-use state estimation model. A set of experiments demonstrates the accurate state estimation performance of AllSight.

翻译：触觉感知是机器人手部完成精细操作并与环境交互的必要能力。光学传感器是实现高分辨率接触估计的可行方案，但其通常制造困难且需逐一标定以实现足够精度。本文提出AllSight——一种专为机器人手内操作任务设计的圆形三维结构光学触觉传感器。AllSight主体采用3D打印工艺，具有低成本、模块化、耐用性及人类拇指大小尺寸的同时，兼具大接触面积。我们展示了AllSight学习并估计完整接触状态（即接触位置、力与扭矩）的能力，并提供了不同照明配置与接触弹性体之间的实验基准。此外，AllSight的稳健设计赋予其独特的零样本能力，使得使用者可基于开源设计直接制造传感器并获取可直接使用的状态估计模型。系列实验验证了AllSight准确的状态估计性能。