A task oriented haptic gait rehabilitation robot

This paper presents the concept, design process, and the prototype of a novel haptics-based lower-extremity rehabilitation robot for bed-ridden stroke patients. This system, named Virtual Gait Rehabilitation Robot (ViGRR), is required to provide the average gait motion training as well as other targeted exercises such as leg press, stair stepping and motivational gaming, in order to facilitate motor learning and enable the training of daily activities such as walking and maintaining balance. The system requirements are laid out and linked to the design of a redundant planar 4DOF robot concept prototype. An iterative design optimization loop was setup to obtain the robot kinematic and dynamic parameters as well as the actuators. The robot’s mechanical design, model, safety features, admittance controllers, and the architecture of the haptic controller are presented. Preliminary experiments were planned and performed to evaluate the capability of the system in delivering task-based virtual-reality exercises and trajectory following scenarios.