• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.63-68
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• 1987

In this study, a pantograph leg of the four legged walking vehicle is analysed with regard to mechanical energy consumption. Energy efficiency of the vehicle is estimated in terms of specific resistance varying body height, stride length and walking speed. The interaction between specific resistance and the parameters is investigated.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.7-16
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• 2003

The purpose of this study was to investigate the effect of Treadmill Training with FES(TTF) on walking velocity, gait endurance, and energy expenditure index(EEI) of hemiplegia patients with foot drop. Two subjects with hemiplegia participated in this study. They took walking excercise 5 times per week for 8 weeks. One time excercise spent 30minutes. The theraputic effect was evaluated by how many seconds they needed to walk 10 meters, how far they could walk for 12 minutes, and how much they spent energy in walking for 12 minutes. Two cases were examined before, after 4 week, and after 8 week, walking training. The results of this study are as follows; 1) Walking velocity : Case 1 increased from 0.52m/sec before walking training to 0.83m/sec after 8 weeks. Case 2 increased from 0.58m/sec to 0.92m/sec. 2) Gait endurance : Case 1 increased from 383.23m to 625.53m. Case 2 increased from 410.19m to 693.47m. 3) EEI : For comfortable walking condition, Case 1 decreased from 0.98beats/min to 0.71beats/min, and Case 2 decreased from 0.93beats/min to 0.68beats/min. For maximum walking condition, Case 1 decreased from 0.93beats/min to 0.67beats/min, and Case 2 decreased from 0.91beats/min to 0.61beats/min. The findings suggest that hemiplegia patients can improve their walking velocity, gait endurance and energy expenditure index through TTF.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.309-312
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• 2003

Though a legged robot has high terrain adaptability as compared with a wheeled vehicle, its moving speed is considerably low in general. For attaining a high moving speed with a legged robot, a dynamically stable walking, such as running for a biped robot and a trot gait or a bound gait for a quadruped robot, is a promising solution. However, energy efficiency of a dynamically stable walking is generally lower than the efficiency of a stable gait such as a crawl gait. In this paper, we present an experimental study on the energy efficiency of a quadruped walking vehicle. Energy consumption of two walking patterns for a trot gait is investigated though experiments using a TITAN-VIII.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.6
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• pp.3-14
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• 2018

The aim of this study is to propose a method for calculating the weight of walking energy in ERAM model by calculating it for the analysis of vertical and horizontal spaces in a building. Conventional theories on the space analysis in the field of architectural planning predict the pedestrian volume of network spaces in urban street or in two-dimensional plane within a building, however, for vertical and horizontal spaces in a building, estimates of the pedestrian volume by those theories are limited. Because in the spatial syntax and ERAM model have been applied weights such as the spatial depth, adjacent angles, and physical distances available only to the two-dimensional same layer or plane. Therefore, the following basic assumptions and analysis conditions in this study were established for deriving a predictor of pedestrian volume in vertical and horizontal spaces of a building. The basic premise of space analysis is not to address the relationship between the pedestrian volume and the spatial structure itself but to the properties of spatial structure connection that human beings experience. The analysis conditions in three-dimensional spaces are as follows : 1) Measurement units should be standardized on the same scale, and 2) The connection characteristics between spaces should influence the accessibility of human beings. In this regard, a factor of walking energy has the attributes to analyze the connection of vertical and horizontal spaces and satisfies the analysis conditions presented in this study. This study has two implications. First, this study has shown how to quantitatively calculate the walking energy after a factor of walking energy was derived to predict the pedestrian volume in vertical and horizontal spaces. Second, the method of calculating the walking energy can be applied to the weights of the ERAM model, which provided the theoretical basis for future studies to predict the pedestrian volume of vertical and horizontal spaces in a building.

• Fire Science and Engineering
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• v.34 no.2
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• pp.41-48
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• 2020

During fire outbreaks, smoke accumulates from the ceiling and reduces the available walking height of people passing through. In this study, a walking experiment was conducted to investigate the relationship between the walking speed of people and available walking height. Twenty-three participants were enrolled. Based on the results, the lower the available walking height, the lower the average walking speed of the participants. However, a significant difference was noted only in the walking speed when the available walking height was 1.2 m compared to the free walking speed. In addition, there was no significant difference among participants in terms of their BMI index grade. However, in the case of participants with normal BMI, the walking speed at a 1.2 m available walking height was significantly lower than when walking freely. Further, in the case of overweight participants, the walking speed at 1.8 m and 1.7 m available walking height was significantly increased compared to that when walking freely.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1029-1036
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• 2011

An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.204-207
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• 2005

Until present, most studies about energy efficiency of quadruped walking robot are mathematical modelings, dynamic analysis or simulation consumption energy per period by basic efficiency evaluate in this paper, a quadruped walking robot Titan-VIII is used for walking experience. The total moving length is about 2[m]. The stride length is 0.1, 0.2, 0.3, walking period is changed by 1.0, 1.5, 2.0, 3.0[sec] per each stride length. So consumption energy of 12 cases are measured. The energy efficiency of quadruped walking robot was analyzed by data that is saved by an experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.446-449
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• 2002

Quadruped walking robot requires dynamic control to keep its stability in high speed walking. To keep its walking stability by control of only legs' Joint angle lowers energy efficiency. It is known that an animal or a human use the moving of the mass center of one's upper body to keep the stability. We have developed a quadruped walking robot with weight balancing oscillator that have high energy efficiency. In this study, walking tests are performed for the robot to verify the validity of the weight balancing oscillator.

• Structural Engineering and Mechanics
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• v.71 no.3
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• pp.245-255
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• 2019

In this paper, an inverted-pendulum model consisting of a point supported by spring limbs with roller feet is adopted to simulate human walking load. To establish the kinematic motion of first and second single and double support phases, the Lagrangian variation method was used. Given a set of model parameters, desired walking speed and initial states, the Newmark-${\beta}$ method was used to solve the above kinematic motion for studying the effects of roller radius, stiffness, impact angle, walking speed, and step length on the ground reaction force, energy transfer, and height of center of mass transfer. The numerical simulation results show that the inverted-pendulum model for walking is conservative as there is no change in total energy and the duration time of double support phase is 50-70% of total time. Based on the numerical analysis, a dynamic load factor ${\alpha}_{wi}$ is proposed for the traditional walking load model.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.215-219
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• 2003

In this paper, we generate a trajectory minimized the energy gait of a biped robot for walking a staircase using genetic algorithms and apply to the computed torque controller for the stable dynamic biped locomotion. In the saggital plane, a 6 degree of freedom biped robot that model consists of seven links is used. In order to minimize the total energy efficiency, the Real-Coded Genetic Algorithm (RCGA) is used. Operators of genetic algorithms are composed of a reproduction, crossover and mutation. In order to approximate the walking gait, the each joint angle is defined as a 4-th order polynomial of which coefficients are chromosomes. Constraints are divided into equality and inequality. Firstly, equality constraints consist of position conditions at the end of stride period and each joint angle and angular velocity condition for periodic walking. On the other hand, inequality constraints include the knee joint conditions, the zero moment point conditions for the x-direction and the tip conditions of swing leg during the period of a stride for walking a staircase.