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：触觉感知是机械手执行精细操作与环境交互的必备能力。光学传感器是实现高分辨率接触估计的有效解决方案，但其通常制造困难且需要单独校准才能达到足够的精度。本文提出AllSight——一种专为机械手抓取操作任务设计的圆形三维结构光学触觉传感器。AllSight主要采用3D打印技术制造，具有低成本、模块化、耐用且尺寸接近人类拇指的特点，同时拥有较大的接触表面。我们展示了AllSight学习并估计完整接触状态（即接触位置、力和扭矩）的能力，并提供了不同照明配置和接触弹性体组合下的实验基准。此外，AllSight的鲁棒设计赋予其独特的零样本能力，使得使用者可直接根据开源设计方案制造传感器并获得可直接使用的状态估计模型。一系列实验验证了AllSight的精确状态估计性能。