Developments of a Knee Motion Assist Mechanism for Wearable Robot with a Non-circular Gear and Grooved Cams
For wearable robot, the active knee joint assist mechanism has been developed. Especially, this mechanism is driven by a non-circular gear and grooved cams. This mechanism rotates and slides simultaneously, which has 2 degree-of-freedom. And relation between a rotation and a sliding motion can approximate arbitrary mathematical function. And using this mechanism, the knee joint can flex until 130degrees. It is larger than the angle of a conventional joint. In this report, the motion of a knee flexion is analyzed. We propose the fundamental design method. And to move smoothly, we investigate the motion curves. And the optimized locus of a non-circular gear pitch and a grooved cam are shown. Also, the prototype knee joint assist mechanism is evaluated. It is clear that proposed mechanism is useful for the motion assist of a knee joint.
KeywordsWearable robot Knee joint Motion assist Non-circular gear Grooved cam
The author is grateful to Dr. Katori, Tecpha-Japan Co., for cooperating to make the non-circular gear.
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