Soft large area FBG tactile sensors for exteroception and proprioception in a collaborative robotic manipulator

Interest in tactile sensing technologies is advancing due to the growing adoption of robots in daily life activities. Human-machine interaction has thus to be safe, and collaborative robotics is becoming increasingly important. The present work features the design, development and preliminary validation of a soft large area sensor for tactile and proprioceptive sensing in a collaborative robotic manipulator. Such a manipulator is shaped to resemble the human hand and within this paper we focused on the index finger. The finger architecture has a design which allows setting up a structured 3D model, with flexible parametrization and fast prototyping. An optical fiber embedding 12 Fiber Bragg Gratings (FBGs) has been integrated in a soft polymeric matrix to mimic human sense of touch abilities of a whole finger. In order to assess the sensorized robotic manipulator, a mechatronic validation platform has been developed and employed. Preliminary results show a mechanical decoupling between exteroceptive and proprioceptive functions, and among the spatially distributed outputs of the sensor array. These results demonstrate the potential of the proposed approach towards achieving dexterous and fine capabilities in the manipulation of objects.

I. Introduction

In recent years tactile sensing technologies are continuously progressing, paving the way for smart robotic systems able to interact with the environment [1] , [2] . A major requirement is thus to ensure a safe interaction with both humans and objects. To this aim, the integration of tactile sensing capabilities, inspired to those of humans, into robotic systems is pivotal.