Pneu-WREX: Pneumatic Wilmington Robotic Exoskeleton
Project collaborators: Eric Wolbrecht, Jiayin Liu, Robert Sanchez, Robert Smith, Sandhya Rao, Dr. Tariq Rahman, Prof. Steve Cramer, Prof. Jim Bobrow, Prof. David Reinkensmeyer
Supported by: NIH N01-HD-3-3352 from NCMRR and NIBIB
The goal of this project is to develop a robotic exoskeleton that can assist in rehabilitation therapy of naturalistic arm movement. We addressed the engineering challenge of a high degree-of-freedom, powerful, lightweight device by incorporating an anti-gravity orthosis (originally developed by Tariq Rahman and collaborators at the A.I. Dupont Institute) to support the arm and reduce actuator burden, and by using low-cost, pneumatic actuators, controlled with advanced non-linear control algorithms, to power the device. Low-level pneumatic force control is achieved with feedback linearization. The high-level controller for the robot is designed to "assist-as-needed": it allows free voluntary movements toward a target while resisting movements away from the target. When the target cannot be reached voluntarily, the controller slowly builds up force, pushing the arm towards the target.
Movie 1: Non-disabled subject with arm relaxed. Robot moves arm to target.