• 한국정밀공학회지
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• 제17권9호
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• pp.133-144
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• 2000

The dynamic walking planning and the inverse dynamics of the biped robot is investigated in this paper. The biped robot is modeled with 14 degrees of freedom rigid bodies considering the walking pattern and kinematic construction of humanoid. The method of the computer aided multibody dynamics is applied to the dynamic analysis. The equations of motion of biped are initially represented as terms of the Cartesian corrdinates then they are converted to the minimum number of equations of motion in terms of the joint coordinates using the velocity transformation matrix. For the consideration of the relationships between the ground and foot the holonomic constraints are added or deleted on the equations of motion. the number of these constraints can be changed by types of walking patterns with three modes. In order for the dynamic walking to be stabilizable optimized trunk positions are iteratively determined by satisfying the system ZMP(Zero Moment Point) and ground conditions.

• 재활복지공학회논문지
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• 제10권4호
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• pp.321-328
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• 2016

본 논문에서는 신체의 노화로 인해 보행활동이 제한되는 고령자가 사용하는 전동형 보행보조시스템의 조작 편리성 향상을 위해 기존의 조작 기법인 보행의지 기법과 융합이 가능한 보행상태 기법을 제안한다. 이것은 사용자가 핸들바를 파지하고 있는지 여부를 파악하고 그에 따라 사용자의 보행의지를 판별하는 단순 트리거 신호로 사용한다. 또한 보행의지 파악을 위한 사용자의 보행상태 확인은 레이저 거리 측정 장치를 사용하여 검출된 사용자의 선속도와 회전각속도를 보행보조시스템 중심의 선속도와 회전각속도로 사용한다. 이를 위해 사용자의 양측 다리 중심점을 추정하여 가상의 인체중심점 검출 기법을 제안한다. 실험은 보행자의 선속도 및 회전각속도와 보행 보조시스템 중심의 선속도 및 회전각속도를 비교 분석하는 실험을 진행하였다. 실험 결과, 사용자와 보행보조시스템 중심 간에 선속도와 회전각속도의 오차율은 각각 1%와 2.77%로 나타냈으며, 이는 사용자의 선속도와 회전각 속도를 보행보조시스템의 양측구동기, 속도산출기에 적용이 가능한 것으로 확인했다. 이를 통해 본 논문에서 제안하는 보행의지 기법과 보행상태 기법을 융합한다면 사용자가 보행보조시스템에 끌려가는 현상과 조작 미숙으로 인한 오작동 등이 예방 가능할 것으로 확인되었다.

• The Journal of Korean Physical Therapy
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• 제24권2호
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• pp.73-81
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• 2012

Purpose: The aim of the present study was to measure the standing balance symmetry of stroke patients using a force-plate with computer system, and to investigate the correlation between the standing balance symmetry and that of the walking function in stroke patients. Methods: 48 patients with stroke (34 men, 14 women, $56.8{\pm}11.72$ years old) participated in this study. Static standing balance was evaluated by the weight distribution on the affected and the nonaffected lower limbs, sway path, sway velocity, and sway frequency, which reflected the characteristic of body sway in quiet standing. Dynamic standing balance was evaluated by anteroposterior and mediolateral sway angle, which revealed the limit of stability during voluntary weight displacement. Symmetry index of static standing balance, (SI-SSB) calculated by the ratio of the affected weight distribution for the nonaffected weight distribution, and symmetric index of dynamic standing balance (SI-SDB) by the ratio of the affected sway angle for the nonaffected sway angle. Functional balance assessed by a Berg balance scale (BBS), and the functional walking by 10m walking velocity, as well as the modified motor assessment scale (mMAS). Results: Static balance scales and SI-SSB was the only correlation with BBS (p<0.05). Dynamic balance scales and SI-DSB, not only was correlated with BBS, but also with 10m walking velocity and mMAS (p<0.01). Additionally, there was a significant difference between SI-SSB and that of SI-DSB (p<0.01). Conclusion: The balance and the walking function relate to real life in the stroke showed strong relationships with the dynamic standing balance symmetry in the frontal plane and the ability of anterior voluntary weight displacement in sagittal plane.

• 한국철도학회논문집
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• 제9권3호
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• pp.271-276
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• 2006

Insight into behaviour of pedestrians as welt as tools to assess passenger flow condition is important in such instances as planning and geometric design of railway station under regular and safety-critical circumstances. Algorithm for passenger flow analysis based on DEM (Discrete Element Method) is newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. To verify the effectiveness of new algorithm, passenger flow analysis for the basic models of railway station is conducted.

• The Journal of Korean Physical Therapy
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• 제17권3호
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• pp.339-350
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• 2005

This study is the quasi-experimental study on the gait training rehabilitation. The purpose of this study is to prepare the baseline data for most suitable of gait while we were scrutinizing how the walking characters, functional walking ability, gait quality of stroke patients were affected by the gait on BWSTT (Body Weight Supported Treadmill Training) through the change of treadmill velocity and body weight support. To accomplish this purpose, this study used thirty subjects, more than 3 months post stroke, for rehabilitation who were divided between two gait training groups they received the neurophysiological physical therapy. For 6 weeks, 5 times a week for 15 minutes per session, the BWSTT group participated in 30 sessions structured speed-dependent treadmill training with 30% body weight supported, and the ratio of body weight support was gradually decreased as the patients advanced the capability of more self-support. The OGT(Over Ground Training) group received the same quantity of equal sessions like BWSTT. Firstly, we measured the absolute improvement of walking velocity (m/s), capacity(min/m) and cadence(steps/min) among walking characters. Secondly, we measured the functional walking ability such as Functional Ambulatory Category(FAC, score out of 5), Modified Motor Assesment Scale(MMAS, score out of 6) and Gait Quality Chart(score out of 41). Data analysis was performed with using SPSS 10.0 win program. The descriptive analysis was used to obtain average and standard deviation. The independent t-test and the paired t-test were used to compare both the groups about pre and post training test. Treatment effects were established by pre and post assessment. Subjects tolerated the training well without side-effects. Therefore, the results of this study were as follows; 1. There was a more significant difference from the improvement of walking velocity(0.09m/s), endurance(4.53min/m), cadence(4.20steps/min), FAC(0.26score), MMAS(0.33 score) and hip joint and pelvic of gait quality(0.39 score) ever before in the BWSTT group(p<.05). 2. There was a more significant increase from the walking velocity(0.01m/s) in the OGT group(p<.05). 3. There was a more statistical significant increase from comparing the average of walking velocity in both groups ever before(0.42m/s in BWSTT group and 0.31m/s in OGT group)(p<.05). There was a statistical significant difference from the average of cadence in both groups(61.87step/min in BWSTT group and 3.60steps/min in OGT group)(p<.05). As we can see from above, the findings suggest that BWSTT may be more effective than the OGT for improving some gait parameters such as gait velocity and cadency. This conclusion also suggest that BWSTT is more effective for the improvement of gait of stroke patients.

• 한국지능시스템학회논문지
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• 제20권2호
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• pp.181-188
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• 2010

본 논문은 능동형 보행보조기 이동시 사용자의 보행의지에 의해 바퀴에 걸리는 외력을 추정하여 보행보조기를 제어하기 위한 차량제어 알고리즘에 관한 논문이다. 최근 노인 인구의 증가로 인해 노인 및 장애인을 위한 보행보조기에 대한 관심이 증가되고 있다. 이에 따라 다양한 보행보조기가 개발되고 있으나, 대부분의 경우 동력이 없는 시스템으로써 경사 등의 공간에 취약성을 가지고 있다. 이에 능동형 보행보조기에 대한 관심이 증가되고 있으나, 능동형 보행보조기의 경우 사용자의 의지 파악이 정확히 이루어지지 않아 보행보조기의 조종이 여의치 않다. 이를 극복하기 위해 사용자의 보행의지를 파악할 수 있도록 다양한 장치를 연구 중에 있으나, 정확한 보행의지력 인지가 어려운 형편이다. 이에 본 논문에서는 이러한 사용자 보행의지력을 기존에 외부에 다양한 장치를 통해 인지하는 방법에서 벗어나, 특별한 장치 없이 차량의 바퀴에 걸리는 외력을 기초로 차량을 제어한다. 이를 위해 먼저 바퀴에 전달되는 전압과 바퀴의 현재 속도를 통해 바퀴에 걸리는 외력을 추정하고 이를 토대로 바퀴에 걸리는 외력을 추정한다. 이 추정된 외력을 기초로 사용자의 보행 속도와 방향을 추정할 수 있도록 하였다.

• 대한물리의학회지
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• 제5권4호
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• pp.569-576
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• 2010

Purpose : This study was aimed at determining the effects of community-based exercise program to improve leg muscle strength and balance for elderly women. Methods : This study was nonequivalent control group pre-post test design. Subjects were assigned to two different groups(exercise group=11, control group=7). Exercise group performed community-based exercise program for 8 weeks. Outcome measures included leg muscle strength, balance, walking velocity, activities of daily living(ADL), exercise self-efficacy and health-related quality of life(QoL). The collected data analyzed by independent t-test and paired t-test. Results : Leg muscle strength, walking velocity and mental component summary(QoL) were significantly improved in the exercise group. But balance and exercise self-efficacy were significantly worsened in the control group. There were no significant difference between groups after 8 weeks of community-based exercise. Conclusion : These results suggested that the community-based exercise program is effective for elderly women in improving leg muscle strength, walking velocity and mental component summary(QoL).

• 대한인간공학회지
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• 제11권1호
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• pp.93-101
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• 1992

Gait parameters for the Korean normal adults were compared with sex and age. Time-distance measurements and ground reaction force parameters were studied in relation to walking speed. Regression analysis was performed to establish functional relations between walking speed and various gait parameters. It is found that cardence and stride length varied linearly with walking velocity whereas time of double support was inversely proportional to walking velocity. The amplitude of ground reaction force was increased with increasing velocities of gait due to the greater heel-strike force and toe-off forces associated with these higher velocities. The results of this study can be usefull utilized as basic data to design and evaluate prosthetic devices, and to detect abnormal gait performances.

• 한국화재소방학회논문지
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• 제25권1호
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• pp.72-77
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• 2011

현대 도시는 수평적 토지이용의 제한, 지가 상숭, 인간 요구의 다양화 등으로 인하여 도시기능의 일부를 지하공간으로 흡수하고자 하는 노력이 증가하는 추세이다. 따라서 건축물의 지하층, 지하철 역사 등이 점차 대심도화 되어 지하공간에서 지상으로 피난에 대한 안전성 여부가 부각되고 있다. 그동안 계단에서 군집보행에 관한 연구는 내려가는 군집보행을 중심으로 진행되어 왔으며, 계단에서 올라가는 군집보행에 대한 연구는 거의 전무한 상황이다. 본 연구에서는한 방향 군집유통이 형성되는 지하철 역사 숭강장 내 계단에서 올라가는 군집의 밀도에 따른 보행속도를 직접 실촉하여 조사하였다. 올라가는 보행은 실측결과 경사도 $23^{\circ}$에서 관계식 V=0.638-0.0949p에 의해 보행속도가 결정되며, 이를 일본건축학회에서 제안하는 계단 경사도에 따른 평균보행속도를 근거로 환산하면 경사도 $30^{\circ}$에서는 V=0.597-0.1067p가 되는 것으로 분석되었다.

• 대한기계학회논문집
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• 제14권6호
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• pp.1455-1463
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• 1990

In this study the feasibility of a dynamic gait for a given quadruped walking robot is investigated through a computer simulation of the walking with certain drivings of the actuators. Two planar inverted pendulums are used to represent the dynamic model of the leg of the walking robot. It's gait motion is assumed to be periodic and symmetric between left and right sides only with half cycle delay. The dynamics of the walking robot is simplified by introducing two virtual legs to produce two planar inverted pendulums in two orthogonal planes and on the basis that certain legs in pair act as one. The feasibility of the dynamic gait motion is established from the following two necessary conditions:(1) The position and velocity of a foot must satisfy the stroke and velocity requirements.(2) The gait motion should be periodic without falling down. The gait feasibility test was applied to a walking robot design showing the specific acceptable speed range of the robot in trot. Also it showed that the higher body height may produce the faster trot gait.