Towards the Development of Advanced Exoskeletons for Supporting the Human Activities

Exoskeletons find application in many fields and can be divided into three main categories: 1) haptic interfaces; 2) power amplifiers; 3) rehabilitation and assistance systems. A number of research groups have developed a number of robotic solutions for supporting the motor activities of the upper limb by integrating advanced technologies in terms of actuation, sensors, control and mechanisms. For example, D.A. Caldwell (2003) proposed an upper limb rehabilitation exoskeleton using McKibben PMA applied to a rigid link structure [1]. The same actuators but different approach are used by H. Kobayashi (2004) by integrating the McKibben actuators into a power suit in a configuration similar to the natural muscles [2]. Other research groups focus on the control strategy. J. Rosen (2005) developed a new arm exoskeleton with 7 dof where the motions and the torques of the shoulder and of the elbow are predicted by using genetic algorithm based on the Hill-type muscle model, and EMG, position e force interface information [3]. K. Kiguchi (2005) proposed a cable-driven exoskeleton actuated by DC motors and using neuro-fuzzy logic to control and to predict the shoulder and elbow movements [4],[5]. A different approach has been pursued by K. Yamamoto (2004) who designed a complete power suit using custom pneumatic actuators for assisting nurses in lifting of patients [6]. The Maryland-Georgetown Army (MGA) Exoskeleton shows interesting solutions to the problem of kinematics coupling between the exoskeleton structure and the human shoulder [7]. It is important to point out that in a microgravity environment the astronauts spend most the time doing motor exercises, so he/she could be considered as impaired people carrying out rehabilitation exercises. In addition, robotic systems could be wearable under the power suit and could be used to feedback to the astronaut cognitive sensations. This paper presents the design methodology and the ongoing activities at ARTS Lab of the Scuola Superiore Sant’Anna towards the design and development of an innovative exoskeleton for the upper limb and of advanced wearable interfaces for cognitive feedback.