Design, Modelling, and Development of Adaptive Robot Grippers and Hands for Robust Grasping and Dexterous Manipulation

Abstract

Robots are increasingly becoming an integral part of our lives, participating and collaborating with humans in various roles, from automating tasks in industry, service, and home environments to assisting and augmenting humans to regain their original quality of living or further improve their capabilities. As such, the tasks executed by robotic systems are also constantly growing in sophistication. Grasping and dexterous manipulation are critical capabilities that allow humans to execute complex everyday life tasks, enabling them to interact with their environment (e.g., grasping an object, pushing a button, opening a door, etc.). In robotics, for such complex tasks the devices that are typically employed are either fully actuated, multi-fingered, and rigid robot hands that are expensive and that require advanced sensing elements and complicated control laws or simple robotic grippers that offer limited dexterity and rely on robotic manipulators to accomplish the tasks. In this PhD thesis, we focus on the design, analysis, and development of adaptive, underactuated, and soft robot grippers and hands that can provide robust grasping and dexterous manipulation capabilities to robotic systems operating in dynamic and unstructured environments. To do so, we propose new designs and methods of introducing compliance to the end-effector structures, new selectively lockable differential mechanisms, new multi-modal gripping systems, reconfigurable bases that increase the dexterity of an end-effector without increasing complexity, and variable stiffness actuators that increase the system capabilities in both grasping and manipulation. All the designs and mechanisms proposed have been analyzed and integrated in a series of robotic grippers and hands that can be efficiently used in a wide range of applications, requiring minimal sensing and control in order to be operated. In order to evaluate the performance of the proposed robot grippers and hands, we conducted a plethora of experiments focusing on their grasping, manipulation, reconfiguration, stiffness modulation, and force exertion capabilities.