| Preliminary development of the Virtual Gait Rehabilitation Robot (ViGRR) has realized the concept platform into a 4-link planar robot, which has been verified through force controlled experiments involving a user's hand.;This thesis presents the further development of ViGRR into a lower extremity haptic rehabilitation platform. Hardware modifications of the ViGRR platform, which are necessary for human experiments are assessed and completed. These modifications include a patient seat, base platform, electronic interface board, updated kinematic calibration, more reliable limit switches, and a magnetically detachable foot plate for safe human-robot interaction. This thesis then describes the development, implementation, and verification of a real-time compatible 6-DoF haptic rendering technique, which will be used for the subsequent experiments. Experiments are then conducted with a human subject in order to assess the ability of ViGRR to reproduce the swing and stance phase of a gait cycle normally seen through walking. The results from the stance phase experiments prove that a scaled version of the vertical ground reaction force can be produced. The swing phase experiments, however, show that the impedance parameters of the current control scheme prevent the subject from attaining a smooth tracking of a gait trajectory. Finally, a set of virtual reality exercises are designed and evaluated in order to highlight the capabilities of ViGRR with respect to lower extremity physical rehabilitation. |
