Instrumenting a Robotic Finger to Augment the Capabilities of Robotic Grippers

Robots are helping humans perform tasks, especially in industry. The collaboration between humans and machines is considered to be among the principal factors underlying the so-called Industry 4.0. To boost such a form of collaboration, robots could be provided with a higher degree of instrumentation, which undoubtedly resorts to a reliable sensorization. In this regard, the robot end-effector is central, being often the interaction organ of the robot. The present article aims at delivering a device, namely, instrumented finger (IF), which can be mounted on robotic end-effectors such as grippers. The device is able to sense the grasping force and the associated bending moment, thanks to an integrated load cell. It also has a tactile matrix through which the center of pressure can be determined, as well as the slip. Furthermore, the device electronics includes an inertial sensor. Cables are protected by covers which hide the inner metallic body and the electronics. The device is compact, robust, and precise, and it constitutes a promising solution for the instrumentation of robotic grippers. In the present article, the IF functionalities, such as measurement of force, torque, acceleration, and CoP, will be demonstrated. Furthermore, it will be shown the IF integration on a real industrial gripper mounted on a robotic arm, executing slip compensation experiments and mass estimation of grasped items.