Özet:

Two major defects of the exoskeleton’s single-axis knee joint were exposed in human-machine coordination experiments, which are chattering of hip and knee joints and pull-feeling at ankle joint. In order to analyze and solve these issues, human gait experiments were conducted to obtain the human gait data, and a kinematic model of the exoskeleton was established. Kinematics analysis of the exoskeleton based on the human’s hip and knee joint angles indicated the obvious human-machine ankle joint movement error; inverse kinematics analysis of the exoskeleton according to the human ankle joint trajectory reflected the abrupt angle changes of exoskeleton’s hip and knee joints. According to these analysis results, kinematics differences between the exoskeleton’s single-axis knee joint and human’s trochlea knee joint were regarded as the primary cause of the defects observed in human-machine coordination experiments. The exoskeleton’s knee joint was optimized in four-bar linkage type to imitate the kinematics characteristics of human’s knee joint. Kinematics simulation results of the optimized exoskeleton showed that human-machine ankle joint movement error and abrupt angle changes of the exoskeleton’s hip and knee joints have been both significantly reduced, thus the effectiveness of the exoskeleton’s knee joint optimization for improving the human-machine coordination could be confirmed.

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