Design and control of an active knee exoskeleton for walking assistance of CP hemiplegic patients

Patients affected by Cerebral Palsy show various grades of crouch gait. In order to improve their knee extension during the critical phases of walking, they are subjected to physical re- habilitation protocols. This thesis presents the development of a robotic exoskeleton device for the knee joint of hemiplegic patients that could enhance therapy results giving an assistive torque during particular phases of gait. The device features a modular passive knee brace designed for post-op rehabilitation that has been modified with an aluminum motor support. The motor is actuated via Bowden-cable transmission; while a closed-loop controller provides the reactive torque to the patients through high frequency real-time measurements. The time instant in which the assistance is needed is detected by a control software model designed for gait event detection. Preliminary Processor-in-the-loop testing has been made before the validation with human subjects affected by hemiplegia derived from low level Cerebral Palsy. The future investigation with this device will be focused on the improvement of its weight and the control algorithm optimization, which will require an hardware advancement.