• 한국의류산업학회지
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• 제23권1호
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• pp.106-117
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• 2021

This study proposes a design process for an upper limb assistive wearable soft robot that will enable the development of a clothing product for an upper limb assistive soft robot. A soft robot made of a flexible and soft material that compensates for the shortcomings of existing upper limb muscle strength assistive devices is being developed. Consequently, a clothing process of the upper limb assistive soft robot is required to increase the possibility of wearing such a device. The design process of the upper limb auxiliary soft robot is presented as follows. User analysis and required performance deduction-Soft robot design-upper limb assistive wearable soft robot prototype design and production-evaluation. After designing the clothing according to the design process, the design was revised and supplemented repeatedly according to the results of the clothing evaluation. In the post-production evaluation stage, the first and second prototypes were attached to actual subjects, and the second prototype showed better results. The developed soft robot evaluated if the functionality as a clothing function and the functionality as the utility of the device were harmonized. The convergence study utilized a process of reducing friction conducted through an understanding and cooperation between research fields. The results of this study can be used as basic data to establish the direction of prototype development in fusion research.

• 로봇학회논문지
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• 제12권3호
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• pp.356-364
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• 2017

This paper presents a force control based on the observer without taking any force or torque measurement from the robot which allows realizing more stable and robust human robot interaction for the developed multi-functional upper limb rehabilitation robot. The robot has four functional training modes which can be classified by the human robot interaction types: passive, active, assistive, and resistive mode. The proposed observer consists of internal disturbance observer and external force observer for distinctive performance evaluation. Since four training modes can be quantitatively identified as impedance variation, position-based impedance control with feedback and feedforward controller was applied to the assistive training mode. The results showed that the proposed sensorless observer estimated cleaner and more accurate force compared to the force sensor and the impedance controller embedded with the proposed observer completed the assistive training mode safely and properly.

• 한국의류학회지
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• 제44권6호
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• pp.1107-1119
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• 2020

This study analyzed a subject's body reaction and subjective sensation when wearing a gait-assistive rehabilitation robot. The research method measured skin and clothing surface temperatures for 'seating-standing' and 'walking in place' exercises after wearing a gait-assistive rehabilitation robot. In addition, subjective sensation and satisfaction were evaluated on a 7-point Likert scale. The study results showed that the average skin temperature during exercise while wearing the gait-assistive rehabilitation robot was within a comfortable range. However, during the 'seating-standing' exercise, the skin temperature was slightly lowered. Additionally, the clothing surface temperature tended to be lower than the pre-exercise temperature after all exercises. The subjective sensation evaluation results showed that the wear comfort of the waist part was low during mobility/activity. In addition, an overall improvement in the wear comfort of the robot is necessary. The short-time movement of wearing and walking in the gait-assistive rehabilitation robot did not interfere with the thermal comfort of the body. However, the robot needs to be ergonomically improved in consideration of the long wearing time along with improved material that to satisfy overall wearing comfort.

• 로봇학회논문지
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• 제8권1호
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• pp.8-19
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• 2013

One of the important issues for structural and electrical specifications in developing a robot is to determine lengths of links and motor specifications, which need to be appropriate to the purpose of robot. These issues become more critical for a gait rehabilitation robot, since a patient wears the robot. Prior to developing an entire gait rehabilitation robot, designing of a 1DOF assistive knee joint of the robot is considered in this paper. Human gait motions were used to determine an allowable range of knee joint that was rotated with a linear type actuator (ball-screw type) and links. The lengths of each link were determined by using an optimization process, minimizing the stroke of actuator and the total energy (kinetic and potential energy). Kinetic analysis was performed in order to determine maximum rotational speed and maximum torque of the motor for tracking gait trajectory properly. The prototype of 1 DOF assistive knee joint was built and examined with a impedance controller.

• 로봇학회논문지
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• 제1권1호
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• pp.1-8
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• 2006

In this paper, we propose a methodology for classifying types of lower limb disability and their mechanical structure, based on extensive survey of previous developments. We also propose a task-oriented design with human-friendly and energy-efficient assistive system. The result can be used for optimal design of wearable walking-assistive robot considering the type of disability and the content of task.

• 제어로봇시스템학회논문지
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• 제21권6호
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• pp.538-546
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• 2015

This paper describes an intelligent ankle assistive robot which provides assistive power to reduce ankle torque based on an analysis of ankle motion and muscle patterns during walking on level and sloped floors. The developed robot can assist ankle muscle power by driving an electric geared motor at the exact timing through the use of an accelerometer that detects gait phase and period, and a potentiometer to measure floor slope angle. A simple muscle assistive link mechanism is proposed to convert the motor torque into the foot assistive force. In particular, this mechanism doesn't restrain the wearer's ankle joint; hence, there is no danger of injury if the motor malfunctions. During walking, the link mechanism pushes down the top of the foot to assist the ankle torque, and it can also lift the foot by inversely driving the linkage, so this robot is useful for foot drop patients. The developed robot and control algorithm are experimentally verified through walking experiments and EMG (Electromyography) measurements.

• 로봇학회논문지
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• 제18권4호
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• pp.376-384
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• 2023

In this paper, we introduce an upper extremity rehabilitation robot, NREH (NRC End-effector based Rehabilitation arm at Home). Through NREH, stroke survivors could continuously exercise their upper extremities at home. NREH allows a user to hold the handle of the end-effector of the robot arm. NREH is a end-effector-based robot that moves the arm on a two-dimensional plane, but the tilt angle can be adjusted to mimic a movement similar to that in a three-dimensional space. Depending on the tilting angle, it is possible to perform customized exercises that can adjust the difficulty for each user. The user can sit down facing the robot and perform exercises such as arm reaching. When the user sits 90 degrees sideways, the user can also exercise their arms on a plane parallel to the sagittal plane. NREH was designed to be as simple as possible considering its use at home. By applying error augmentation, the exercise effect can be increased, and assistance force or resistance force can be applied as needed. Using an encoder on two actuators and a force/torque sensor on the end-effector, NREH can continuously collect and analyze the user's movement data.

• 로봇학회논문지
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• 제14권4호
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• pp.318-325
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• 2019

NREX, an upper limb exoskeleton robot, was developed at the National Rehabilitation Center to assist in the upper limb movements of subjects with weak muscular strength and control ability of the upper limbs, such as those with hemiplegia. For the free movement of the shoulder of the existing NREX, three passive joints were added, which improved its wearability. For the flexion/extension movement and internal/external rotation movement of the shoulder of the robot, the ball lock pin is used to fix or rotate the passive joint. The force and torque between a human and a robot were measured and analyzed in a reaching movement for four targets using a six-axis force/torque sensor for 20 able-bodied subjects. The addition of two passive joints to allow the user to rotate the shoulder can confirm that the average force of the upper limb must be 31.6% less and the torque must be 48.9% less to perform the movement related to the axis of rotation.

• 전자공학회지
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• 제36권8호
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• pp.912-920
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• 2009

• 대한기계학회논문집A
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• 제38권7호
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• pp.799-807
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• 2014

본 논문에서는 가용공간이 적은 실내에서의 사용을 중점으로 한 새로운 방식의 구동방식을 갖는 전동 볼체어의 개발을 소개하고자 한다. 볼체어의 가장 큰 특징은 크게 두 가지로 나뉜다. 첫째는, 구조적 특징으로서 부피와 무게를 최소화하기 위해 원형에 가까운 모양의 팔각형 외골격 프레임 설계를 수행하였고, 공을 포함한 모든 구동부가 로봇 내부에 장착되어 크기뿐만 아니라 사용안전성 면에서 실내용으로 적합하도록 설계하였다. 둘째는, 구동 메커니즘의 특징으로서 볼마우스의 동작 원리를 역발상하여 로봇의 구동방식에 적용하였다. x축, y축의 회전을 담당하는 두 개의 옴니휠이 공을 굴리는 방식으로 각각 모터의 속도를 제어하여 두 개의 바퀴만으로 전 방향 구동이 가능한 홀로노믹 시스템을 구현하였다. 이러한 두 가지의 특징으로부터 볼체어가 좁은 이동 공간에서 전방위 이동을 효과적으로 수행할 수 있음을 실험적으로 구현하였으며, 본 로봇의 자세한 개발 과정을 본 논문에 서술하였다.