One of the major limitations to the use of advanced robotic hands in industries is the complexity of the control system design due to the large number of motors needed to actuate their degrees of freedom. It is our belief that the development of a unified control framework for robotic hands will allow us to extend the use of these devices in many areas. Borrowing the terminology from software engineering, there is a need for middleware solutions to control the robotic hands independently from their specific kinematics and focus only on the manipulation tasks. To simplify and generalize the control of robotic hands, we take inspiration from studies in neuroscience concerning the sensorimotor organization of the human hand. These studies demonstrated that, notwithstanding the complexity of the hand, a few variables are able to account for most of the variance in the patterns of configurations and movements. The reduced set of parameters that humans effectively use to control their hands, which are known in the literature as synergies, can represent the set of words for the unified control language of robotic hands, provided that we solve the problem of mapping human hand synergies to actions of the robotic hands. In this study, we propose a mapping designed in the manipulated object domain in order to ensure a high level of generality with respect to the many dissimilar kinematics of robotic hands. The role of the object is played by a virtual sphere, whose radius and center position change dynamically, and the role of the human hand is played by a hand model referred to as ``paradigmatic hand,'' which is able to capture the idea of synergies in human hands

Abstract-In this paper the problem of a quadrotor that physically interacts with the surrounding environment through a rigid tool is considered. We present a theoretical design that allows to exert an arbitrary 3D force by using a standard nearhovering controller that was originally developed for contactfree flight control. This is achieved by analytically solving the nonlinear system that relates the quadrotor state, the force exerted by the rigid tool on the environment, and the nearhovering controller action at the equilibrium points, during any generic contact. Stability of the equilibria for the most relevant actions (pushing, releasing, lifting, dropping, and leftright shifting) are proven by means of numerical analysis using the indirect Lyapunov method. An experimental platform, including a suitable tool design, has been developed and used to validate the theory with preliminary experiments.

Abstract-The flying hand is a robotic hand consisting of a swarm of UAVs able to grasp an object where each UAV contributes to the grasping task with a single contact point at the tooltip. The swarm of robots is teleoperated by a human hand whose fingertip motions are tracked, e.g., using an RGB-D camera. We solve the kinematic dissimilarity of this unique master-slave system using a multi-layered approach that includes: a hand interpreter that translates the fingertip motion in a desired motion for the object to be manipulated; a mapping algorithm that transforms the desired object motions into a suitable set of virtual points deviating from the planned contact points; a compliant force control for the case of quadrotor UAVs that allows to use them as indirect 3D force effectors. Visual feedback is also used as sensory substitution technique to provide a hint on the internal forces exerted on the object. We validate the approach with several human-inthe-loop simulations including the full physical model of the object, contact points and UAVs.

No abstract