| Summary: | 碩士 === 國立臺灣大學 === 電機工程學研究所 === 107 === Stroke is a prevalent source of neurological impairment which causes disability in adults. The survivors of it commonly suffer from motor impairments on both upper and lower limb motion. According to clinical studies, the patients can regain their motor ability by intensively involving in rehabilitation therapy. Introducing upper limb rehabilitation exoskeleton robot into the therapy can not only reduce the labor cost but also provide intensive and accurate treatment. The control strategy for applying robot in rehabilitation therapy can be classified as passive, active, active-resistive and active-assistive control. To implement active-assistive control, both motion intention of the patients and the given rehabilitation task should be taken into consideration so that the controller can provide necessary assistance to achieve the goal. However, most of the rehabilitation task model in related works is a time-dependent trajectory, which limits the freedom of subjects to control actively. An active-assistive controller based on interactive torque observer is proposed for upper limb rehabilitation exoskeleton robot, NTUH-II. First, the motion intention of the subjects can be obtained by utilizing an adaptive Kalman filter based interactive torque observer. Next, we propose a velocity field based task model which can be generated via a given task trajectory. The model only depends on the location information of the subject so that the subject is not limited to achieve the motion at a specific time instant. The proposed active-assistive method can integrate the active and assistive motion based on the performance and the active involvement of the subject. The integration result considers not only the human active intention but also the given task such that the subject can perform the task more actively and accurately. Finally, the stability and effectiveness of the proposed active-assistive control system are verified by Lyapunov stability analysis. Various experiments are conducted on three healthy subjects and NTUH-II to verify the proposed active-assistive control system. The results show that compared with the related works, not only the execution time but also the subjects'' exertion can be reduced when performing the given rehabilitation tasks. In addition, the proposed method can promote subjects'' intention of active motion and assist them to accomplish the tasks accurately. In the future work, the effectiveness of the proposed system for stroke patients is required to be validated through clinical studies.
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