Basic Considerations in the Development of an Exoskeleton for Rehabilitation and Interaction with Virtual Reality

This paper presents the design and development of a whole-body active orthotic system (exoskeleton) for rehabilitation and interaction with virtual reality.The wearable structure comprises upper-limb, lower-limb and central torso modules with 29 degrees of freedom, 14 of which are actuated by antagonistically acting pneumatic artificial muscles that mimic the human muscle-tendonligament structure.Lightweight prototypes in aluminum, plastic and carbon fulfil the design requirements for low mass and inertia, safety and an anthropomorphic range of motion.A distributed control system with multiple microcontroller units implements joint torque and impedance control using feedback from position, force and pressure sensors.The system operates in three modes: as a haptic and rehabilitation device, as an assistive orthosis in cases of impaired muscles, and as a motion tracking system exchanging data with virtual reality.The graphical user interface ExoInterface provides calibration, communication and real-time bidirectional data exchange with a virtual avatar at 170 Hz.Experiments performed in a virtual environment demonstrate accurate motion reproduction and force feedback, confirming the system's potential for assistive and rehabilitation applications for people with limited mobility.