The Design of Bionic Back Shelf for Weight Bearing Exoskeleton

A suitable exoskeleton is able to improve the weight bearing capacity of human and reduce spinal cord injuries caused by long-term works. This paper designs a bionic back shelf for the weight bearing exoskeleton which can fit the back of human well and improve the transmission efficiency of the backpack gravity based on the physiological characteristics of spine. We collected the coordinates of spine through the markers attached to the spinous processes and designed a bionic exoskeleton prototype according to the fitted spine curve. The plantar pressure was obtained by standing and walking by wearing an unpowered exoskeleton with the designed bionic back shelf. We found that the net force transmission efficiency reached 77.1% when a 10kg backpack was carried which rose to 85.1% when the weight of load was added to 20kg while standing with exoskeleton. It was only 18.5% for the whole of supporting state but it reached 61.8% in the mid-support phase during walking which may be caused by the small angle of the hip and knee joints facilitating the transmission of load gravity in the vertical direction. The results illustrated that the exoskeleton with a bionic back frame on the basis of spine curve had high force transmission efficiency in the standing state and the mid-support state of walking.