A Novel Double-Rope BWS System for Locomotion Training of Hemiplegic Patients

Locomotion training with partial body weight support (BWS) is a common clinical practice. Terrestrial locomotion is inherently driven by the ground reaction force (GRF), and existing BWS systems that only provide upward support are not optimal for locomotion training of paraplegic patients who also need support in the forward and lateral direction. In this paper, we designed a novel double-rope body weight support system to provide forward and lateral forces along with the support force against gravity. The dynamical models between the ground reaction forces and the BWS unit cable tension forces were analyzed. The control strategy was proposed to achieve accurate control of cable tension forces and deflection angles, and equivalently the three dimensional supportive forces. Through simulations with measured gait data, the efficacy of the proposed BWS system and control strategy were validated.