One-DOF wire-driven robot assisting both hip and knee flexion motion

Gait assistance robots are used to improve gait performance ability or perform gait motion with an assistance for several articular motions. The sparing use of a gait assistance robot to decrease the duration of the robot’s assistance is important for keeping the ability to perform a movement when the robot assists walking. In previous research, methods of ensuring a compliance mechanism and control method have been studied, and assistance for articular motions has been conducted independently using actuators corresponding to each articular motion. In this paper, we propose a wire-driven gait assistance robot to aid both hip and knee articular flexion motions by applying just one force to assist motion in the swing phase. We focused on a force that assists hip and knee flexion motion, and designed a robot with a compensation mechanism for the wire length. We used an assistance timing detection method for the robot, conducting tensile force control based on information from the hip, knee, and ankle angles. We carried out an experiment to investigate the controlled performance of the proposed robot and the effect on hip and knee angular velocity. We confirmed that the proposed robotic system can aid both hip and knee articular motion with just one force application.