• 전기학회논문지
• /
• 제64권8호
• /
• pp.1231-1239
• /
• 2015

We developed a robot that has four limbs, each of which has the same kinematic structure and has 6 degrees of freedom. The robot is 600mm high and weighs 4.3kg. The robot can perform walking and manipulating task by using the four limbs selectively. The robot has three walking patterns. The first one is biped walking, which uses two rear limbs as legs and two front limbs as arms. The second one is biped walking with supporting arms, which is basically biped walking but uses two arms as supporting legs for increasing stability of the robot. The last one is quadruped walking, which uses all the four limbs as legs. When a task for the robot is given, the robot approaches the task point by selecting an appropriate walking pattern among three walking patterns and performs the task. The robot has many degrees of freedom and is a redundant system for a three dimensional task. We propose a redundancy resolution method, in which the robot’s translational move to the task point is modeled as a prismatic joint and optimal solutions are obtained by optimizing some performance criteria. Several simulations are performed for the validity of the proposed method.

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

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
• /
• pp.87-90
• /
• 2001

This paper presents a design of new type biped robot and dynamic walking simulation for this system. The robot is distinguished from other one by which has a parallel mechanism type trunk and lead-screw type actuators to drive the joints of the trunk, knee and ankle. The basic consideration on the design is that it is able to accommodate itself to human's daily environments without any other modification of around and also to operate its upper limbs more smoothly with a spine functional trunk. It is designed according to a human with about 130 cm height and about 30 kg weight. And it also is able to dynamically walk on an even ground. It has constructed with total 14 DOFs which have two legs, a hip, and a trunk. The joints of each leg and trunk are adopted with a parallel structure which has good kinematic characteristics and take light weight. To test of the capacity of joint actuators and to analysis of the dynamic properties of the biped robot, optimized trunk trajectory is determined by means of an approximated FFT method based on ZMP criteria, and dynamic simulation is performed using DADS with a 1.1 time/step velocity on the even ground during four steps.

• 한국산학기술학회논문지
• /
• 제17권7호
• /
• pp.459-466
• /
• 2016

본 연구는 아급성기 뇌졸중 환자에서 로봇 보조치료법이 운동능력 및 기능적인 회복에 미치는 효과를 알아보고자 하였다. 환자 53명이 연구에 참여하였다. 로봇보조 보행치료군은 고식적인 치료에 추가로 Lokomat$^{(R)}$ 이용하여 하루에 삼십분씩, 일주일에 5회, 4주 동안 시행하였으며, 대조군은 고식적인 치료에 추가로 하루에 삼십분씩 고식적인 치료를 시행 받았다. 모든 환자들은 임상지표의 비교를 위해, 치료 전과 4주간의 치료 후 Fugl-Meyer assessment, Motricity index, functional ambulation category, Berg balance scale, 10m 보행검사, 한국판 수정 바델지수, 한국판 간이 정신 상태검사와 벡 우울증 척도를 평가 받았다. 환자들은 기능회복과 체성 감각 유발전위 검사 결과의 관계를 알아보기 위해 유발 전위 검사를 시행하였다. 아급성기 뇌졸중 환자에서 로봇 보조 보행치료군에서 대조군에 비해 하지의 운동기능, 보행 능력, 일상생활능력의 유의한 호전이 나타났다. 체성 감각 유발 전위 검사의 결과는 임상 지표들의 관련성 분석에서 Motricity index와 한국판 수정 바델지수와 관련이 있는 것으로 나타나 아급성기 뇌졸중 환자의 기능을 예측하는데 유용할 것으로 생각된다. 로봇 보조 보행치료는 아급성기 뇌졸중 환자의 운동기능과 보행기능의 회복을 촉진하는 것으로 생각된다.

• 제어로봇시스템학회논문지
• /
• 제21권1호
• /
• pp.59-64
• /
• 2015

In this paper, we found the usefulness of the deep belief network (DBN) in the fields of brain-computer interface (BCI), especially in relation to imagined speech. In recent years, the growth of interest in the BCI field has led to the development of a number of useful applications, such as robot control, game interfaces, exoskeleton limbs, and so on. However, while imagined speech, which could be used for communication or military purpose devices, is one of the most exciting BCI applications, there are some problems in implementing the system. In the previous paper, we already handled some of the issues of imagined speech when using the International Phonetic Alphabet (IPA), although it required complementation for multi class classification problems. In view of this point, this paper could provide a suitable solution for vowel classification for imagined speech. We used the DBN algorithm, which is known as a deep learning algorithm for multi-class vowel classification, and selected four vowel pronunciations:, /a/, /i/, /o/, /u/ from IPA. For the experiment, we obtained the required 32 channel raw electroencephalogram (EEG) data from three male subjects, and electrodes were placed on the scalp of the frontal lobe and both temporal lobes which are related to thinking and verbal function. Eigenvalues of the covariance matrix of the EEG data were used as the feature vector of each vowel. In the analysis, we provided the classification results of the back propagation artificial neural network (BP-ANN) for making a comparison with DBN. As a result, the classification results from the BP-ANN were 52.04%, and the DBN was 87.96%. This means the DBN showed 35.92% better classification results in multi class imagined speech classification. In addition, the DBN spent much less time in whole computation time. In conclusion, the DBN algorithm is efficient in BCI system implementation.