Design and Strength Verification of a Compact VGFL for Sit-to-Stand Assistance Robot*

This paper introduces a wearable robot which supports frail and elderly people or hemiplegic patients in sit-to-stand transfer of their daily living. The wearable assistive robot is equipped with all components from a power supply to a control system, including variable grounding flexible limbs(VGFL). The VGFL was redesigned to be more compact and stronger than the previous one by optimizing the limb structure so that it could achieve a $40 \%$ reduction in diameter when coiled and a $7 \%$ reduction in limb width, while maintaining a support force of 300 N. In addition to a description of the hardware, this paper also reports on the change in the center of gravity trajectory during standing when using this robot.