중량물 운반 시 인체 근력증강을 위한 하지 외골격 시스템 개발

Abstract

This study developed HEXAR-CR35, a lower limb exoskeleton system aimed at improving the muscle strength of the wearer while moving heavy materials. This system was proposed so that the wearer can move on the ground or climb stairs at a speed of 4km/h carrying a backpack of up to 30kg, with the hips having three DOFs, the knees having one DOF, and the ankles having three DOFs. HEXAR-CR35 was designed to be light and simple. Its energy consumption was decreased by the actuator. The number of sensors for obtaining the wearer's intent was reduced. The system was developed into an under-actuated system for control simplicity with only the knee joints of the exoskeleton operated by the electric motor. To this end, lower limb exoskeleton design, development of sensors for human intent measurement, and development of an exoskeleton controller were conducted. For verification of performance of the HEXAR-CR35 system, human motion following and power augmentation effect experiments were performed. According to the human motion following experiment result, the maximum angle errors during level walking averaged 3.38˚ and during the STS motion it averaged 4.035˚. Nonetheless, because the wearer and the exoskeleton are not rigidly fastened together and the skin and the clothes are soft, the wearer did not feel discomfort for such size of joint error. In the power augmentation effect experiment, %MVIC during gait decreased by more than about 37% when the wearer put on the exoskeleton compared to when the wearer did not. Decrease in %MVIC means that the exoskeleton system improved the wearer's muscle strength. HEXAR-CR35 was developed into an under-actuated system in which the actuator was attached only to the knee joints to be suitable for carrying heavy materials during level walking and stair climbing.