Passive and Active Motion of Single DOF Lower Limb Rehabilitation System

• Main Authors: Kuan-Sheng Chien, 簡冠昇
• Other Authors: 陳金聖
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/376u6p

碩士 === 國立臺北科技大學 === 自動化科技研究所 === 100 === In this study, we present the design and control of single DOF lower limb rehabilitation system for a patient who needs lower limb rehabilitation. Based on physical therapy, we designed two rehabilitation mode for different rehabilitation purposes: (1)Passive-motion mode (2) Active-motion mode. Passive and active motion of single DOF lower limb rehabilitation system has three purposes: (1) to increase the hip and knee range of motion (2) to increase the quadriceps muscle strength and endurance (3) training of the Coordination and balance ability. First, the dynamic model of the rehabilitation machine is derived by the principal of virtual work in dynamics. The major control problem of a rehabilitation machine is to overcome the system parameter variation, since each patient has the different body segment parameters. Sliding-mode control (SMC) is a comprehensive power control scheme which has been successfully used in both linear and nonlinear systems. A major advantage of SMC is their stabilizing properties for dynamic system subject to disturbance and uncertainties. In contrast, the chattering phenomenon is caused by discontinuous hitting control effort. For reducing the chattering phenomenon, we proposed an intelligent sliding-mode control (ISMC) system which involved recurrent Chebyshev neural network (RCNN) estimator to estimate the unknown external disturbance and uncertainty online is proposed to track the angular position and velocity of the rehabilitation machine. Furthermore, we proved that the proposed ISMC system is asymptotically stable via Lyapunov theory. Passive-motion mode of the rehabilitation system is achieved by the ISMC system. For increasing safety and comfort of passive-motion mode, we added position-based impedance control architecture in the ISMC system. If the force sensor which is located at the end-effector of the rehabilitation machine measures an unusual interaction force between patient and machine, the rehabilitation machine can adjust the trajectories immediately for protecting the patient. Moreover, we designed active-motion mode by utilizing this control architecture. It can modulate the intensity in the strength training of active-motion mode through adjusting the parameters in the impedance controller. Finally, the simulation and experiment result proved that the ISMC system has superior load-carrying capacity and tracking ability when it operated in the passive-motion mode. When the rehabilitation system operated in active-motion mode, it can increase the intensity in the strength training by adjusting the parameters in the impedance controller appropriately.