This paper summarizes recent activities carried out for the development of an innovative anthropomorphic robotic hand called the DEXMART Hand. The main goal of this research is to face the problems that affect current robotic hands by introducing suitable design solutions aimed at achieving simplification and cost reduction while possibly enhancing robustness and performance. While certain aspects of the DEXMART Hand development have been presented in previous papers, this paper is the first to give a comprehensive description of the final hand version and its use to replicate human-like grasping. In this paper, particular emphasis is placed on the kinematics of the fingers and of the thumb, the wrist architecture, the dimensioning of the actuation system, and the final implementation of the position, force and tactile sensors. The paper focuses also on how these solutions have been integrated into the mechanical structure of this innovative robotic hand to enable precise force and displacement control of the whole system. Another important aspect is the lack of suitable control tools that severely limits the development of robotic hand applications. To address this issue, a new method for the observation of human hand behavior during interaction with common day-to-day objects by means of a 3D computer vision system is presented in this work together with a strategy for mapping human hand postures to the robotic hand. A simple control strategy based on postural synergies has been used to reduce the complexity of the grasp planning problem. As a preliminary evaluation of the DEXMART Hand’s capabilities, this approach has been adopted in this paper to simplify and speed up the transfer of human actions to the robotic hand, showing its effectiveness in reproducing human-like grasping.

In this document a DC/DC converter for power conversion between +28V/+270V voltage levels is presented, and the main characteristics of the converter are discussed. The topological structure is first introduced, outlining the hardware components used and the modular approach. The step-down (or Buck) and step-up (or Boost) modulations are then discussed, focusing on the switching signals to drive the low-voltage and high-voltage bridges of the single modules. The description of the control phase follows, justifying the controller used to steer the output voltage towards the desired value. The firmware realized for the converter management is equipped also with a supervision and protection logic, realized as a composition of finite state machines. Finally, simulative results and real measurements are provided to evidence the correctness of the overall topological choices and of the control system realized for the bidirectional converter, focusing also on the comparison between the expected results and those obtained.

This paper proposes the analysis of a control loop system employing a Terfenol-D actuator driving a real mechanical load. The aim of the paper is to analyze the performances of such a system when a strategy of hysteresis compensation is employed. Such strategy has demonstrated its effectiveness in simpler feedback systems (with no mechanical load) by improving the tracking error, decreasing the control signal so as to avoid saturation and harmful stress to the actuator. As a consequence, the algorithm allows also to reduce energy losses in the actuator.