基於互動扭矩之下肢外骨骼機器人行走復健設計

Abstract

本研究提出了適應性下肢外骨骼機器人（Adaptive lower limb exoskeleton, AEXO）作為下肢復健用。本研究目的為提供中風或受傷的患者行走復健的順應性演算法。本AEXO之順應性運動控制結合阻抗控制和導納控制，提供患者於復健時之順應性運動，其中導納控制負責產生調整之步態軌跡，而另一方面，阻抗控制負責產生輔助力。在這個外骨骼結構桿件上具有力感測器，以四個應變規作為力感測器之使用，提供力回饋資訊於順應性運動控制之計算，讓患者能改變復健中的步態軌跡和輔助力之大小。步行實驗分為兩個階段，由受試者穿著AEXO進行實驗。第一實驗中使用預設之步態軌跡，該算法可以透過力感測器之回饋資訊，調整預設的移動軌跡和輔助力來適使用者的步態。第二個實驗中沒有使用預設之步態軌跡，受使者在穿戴外骨骼肌器人時，可在不同之步行速度下安全地行走。本演算法實現於實驗室之外骨骼機器人，未來將延伸本研究技術於中風或其他疾病之復健用。

In this research, an adaptive lower limb exoskeleton (AEXO) has been designed and constructed as a rehabilitation device. It is important that the user gets assistance from the exoskeleton in an adaptive manner because the user may improve during the rehabilitation. The degree of assistance from the AEXO depends on the current situation of the user during the use of the exoskeleton. The question then arises as how the exoskeleton provide this adaptive adjustment. It was decided that a tangible idea was to measure the user status such as to measure user interaction force during the walking. In this design, force sensors are installed on each link of the exoskeleton to monitor the user walking effort during walking. By measuring this force, the control computer of this exoskeleton will understand for each cycle what the status of the user is and predict an adaptive torque according to this measured force. In order to generate a suitable torque, the compliant motion control, which is a combination of impedance and admittance control is used. Several walking experiments have been performed by a healthy user equipped with the AEXO. The first experiment verified the proposed algorithm by using a predefined reference trajectory for the user. The second experiment verified that even without the predefined gait trajectory to move the user’s leg, the exoskeleton can give the compliance to the user to walk properly under several walking speeds. For the future development, the method will be expanded to the people who have suffered from the stroke or other injuries.