Mechanical Design for Walking Assist Robot Considering Back Drivability

Abstract

Hip Exoskeleton assist robots are capable of applying strong assistance force to users. However, they often lack back-drivability, leading to the generation of excessive resistance force on the person. Therefore, while there is research aimed at enhancing back-drivability in the direction of leg lifting and lowering during assistance, studies incorporating back-drivability for movements in the leg’s abduction and adduction direction, as well as the internal and external rotation direction of the foot, are limited. In response, we have implemented mechanisms with adjustable compliance for assistance directions and mechanisms that allow for free movement in permitted movement directions. By doing so, we designed mechanisms that possess back-drivability in each direction, and this paper elucidates their utility.