A Novel Wheelchair-Exoskeleton Hybrid Robot to Assist Movement and Aid Rehabilitation

Abstract

As a traditional movement assist equipment for people with lower-limb dysfunction, the wheelchair can support and carry users to perform a long-distance movement indoor and outdoor, however, prolonged inactivity can lead to muscle atrophy and deteriorate motion functions. As a promising solution, the lower limb exoskeleton provides people the ability of standing and walking to avoid these problems. However, the exoskeleton has inevitable shortcomings in long-distance movement and balance, which do not exist in a wheelchair. To integrate the advantages of both devices, in this paper, we proposed a wheelchair-exoskeleton hybrid robot (WeHR) that can not only provide users long-time support and long-distance movement but also provide walking training and keep self-balance. Moreover, motion transitions such as sit-to-stand and stand-to-sit can also be implemented by the newly proposed device without help from caregivers. We have developed the prototype to implement the above functions. In this paper, we emphasize the strategy of motion transition including two trajectory planning methods for the Sit-To-Stand (STS) process as well as the mechanism design to implement it. Furthermore, the preliminary experiments of motion transition and walking test are also conducted and the results prove that our device can support users sitting, standing, and walking and the motion transition.