Development and Validation of a Robotic System Combining Mobile Wheelchair and Lower Extremity Exoskeleton

To promote the rehabilitation training occupied at home, in this article, a wheelchair-exoskeleton system combining the lower extremity exoskeleton (LEE) and the mobile wheelchair is developed to help users to complete the activities of daily life. A hierarchical control architecture is designed and developed for the wheelchair-exoskeleton system. The control architecture is composed of three layers: (1) the top layer is achieved by the task-based voice-controlled strategy through voice recognition; (2) the decision layer produces the intent actions based on the output of the top layer; (3) the execution layer is in charge of controlling the movement of the system, including the gait tracking control of LEE as well as the coordination control of the mobile wheelchair. The mobile wheelchair as a partner works in coordination with the LEE by positioning techniques through utilizing ultra-wideband (UWB) sensors. A small validation study with three able-bodied subjects performing the whole usage process is presented. The experimental results demonstrate that the developed wheelchair-exoskeleton system has the potential to be applied to in-home care with long endurance.