Design, Control, and Assessment of Resilient Robots

Nowadays, robots are widely employed in real and unstructured scenarios, requiring them to cope with unexpected perturbations and safely interact with humans. The ability of human beings to adapt to various situations has become a feature robotic researchers look at with envious eyes while trying to imitate the embodied intrinsic intelligence displayed daily by biological systems. Accordingly, robots are moving towards a better and better resilience to external disturbances, finding applications in various fields, from unstructured environment inspection to human-robot interactions. In this thesis, my efforts are focused on investigating resilience, and approaching this issue in many aspects. Hitherto, robotics resilience and balancing skills evaluation rely on qualitative methods, that are not reliable and hardly repeatable. Hence, I studied and developed a novel methodology to benchmark quantitatively the performance of robots subjected to external perturbations. During this work, I developed repeatable and reliable protocols, performance indicators, and an actuated structure to perform them. Consequently, a substantial effort resulting from the previous analysis is made to enhance the intrinsic resilience of these systems. Robots are often subjected to perturbations or may even encounter failures resulting in falling. In both cases, the robot needs to withstand the stress produced, avoid mishaps, or fail its tasks. I investigated the problem of enhancing resilience by approaching it in two distinct ways. Indeed, the literature shows how resilience is obtained with two approaches. The first is related to resilience injected in the design phase and protects the robot against a large variety of perturbations. The latter is achieved by providing the robot with the ability to detect and react to unexpected events. I approached the design method by analyzing the literature on systems that present impedance in their mechanical composition. During this investigation, particular attention is given to those components that preserve the precision typical of rigid actuation. Later, I designed a compliant damped actuator that employs a differential design. I investigated the reaction methods by designing two different fall-protection integrated safety systems devices and a task resilient active algorithm. More and more dexterous robots are promoting their integration into human daily life, assisting humans in heavy work, dangerous fields, and impaired support. Therefore, resilience has become an indispensable feature.