• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.165-168
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• 2004

본 연구에서는 근골격계로 구성된 신체 역학계와 신경 진동자로 구성된 신경계의 상호작용에 의해서 자율적인 2족 보행운동 생성하려고 하고 있다. 이를 위해서는 역학계와 신경계의 않은 파라메트(Parameter)의 조절이 필요하다 본 연구에서는 유전적 프로그래밍(GP)을 이용하여 파라메트의 자동조절 수법을 제안하였다. GP는 문제를 해결하기 위한 계산 프로그래밍을 탐색하는 진화형 탐색 알고리즘으로, GP를 이용해서 문제해결을 행하기 위해서는 노드의 선택이 매우 중요하다. 그러나 대상문제에 대한 충분한 정보가 없는 경우에는 노드를 용장성 있게 설계하게 되어, 이로 인한 탐색공간의 확장으로 GP에 대한 탐색성능의 저하를 초래한다. 본 논문에서는 이러한 문제를 해결하기 위해서 용장성 노드 집합으로부터 유용한 노드를 획득하기 위해 제안한 수법을 2족 보행운동 생성 시스템에 적용하기 전에 사전 평가로서 기호회귀(Symbolic Regression)문제에 적용하여 실험을 통해 제안 수법의 타당성과 탐색성능 향상의 효과에 관해서 논하고자 한다.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.117-126
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• 2009

The purpose of this study was to investigate the effects of 12-week complex training program on foot pressure patterns of the elderly women. The training program consisted of aerobic exercise and muscular training for 12 weeks. Two stages of walking were given to the participants before and after treatment: (a) straight walking; and (b) turn at $45^{\circ}$ while walking. Data related to foot-pressure distribution(FPD) while walking were collected from each stage and analyzed. Results indicated that in both stage of walking, the mean of the foot pressure(FP) was significantly reduced after the participation in the program. Results also revealed that in all stages, the patterns of the FPD and the center of pressure(COP) were widely lower and more stable. Based on the results of this study, it was concluded that participating in a 12-week complex program bas impact on the gait patterns of the elderly women, reducing the foot pressure on their shoes.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.674-682
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• 2009

The purpose of this study was to investigate the effect of aquatic gait training on plantar foot pressure, foot kinesiology and gait speed in right hemiplegic patients. The subject were 20 stroke patients who elapsed from 12 month to 24 month after stroke(aquatic gait training group(n=10), land gait training group(n=10)). This study measured plantar foot pressure, toe out angle, subtalar joint angle, gait speed from data of gate on 2m long measuring apparatus for RS-scan system(RS scan Ltd. German). This experiment performed in twice, before and after the aquatic gait training and land gait training. Collected data were statistically analyzed by SPSS Ver. 12.0 using descriptive statistics, paired t-test. Aquatic gait training group had more variety pressure area on their foot such as T1(Toe 1), HM(Heel medial), and HL(Heel lateral). But motion of subtalar joint flexibility and toe out angle decreased considerably and gate speed also increased. According to the result, aquatic gait training is considered as more effective way in foot stability and normal gait pattern than land gait training.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.610-616
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• 2004

In the research of biomechanical engineering, robotics and neurophysiology, to clarify the mechanism of human bipedal walking is of major interest. It serves as a basis of developing several applications such as rehabilitation tools and humanoid robots. Nevertheless, because of complexity of the neuronal system that interacts with the body dynamics system to make walking movements, much is left unknown about the details of locomotion mechanism. Researchers were looking for the optimal model of the neuronal system by trials and errors. In this paper, we applied Genetic Programming to induce the model of the nervous system automatically and showed its effectiveness by simulating a human bipedal walking with the obtained model.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.59-65
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• 2008

The purpose of this study was to investigate the shift of COP pathway and the plantar foot pressure among level walking and stairs and ramp climbing in young and elderly people. Plantar foot pressure was measured by MatScan system(Tekscan, USA). Statistical analysis was used One-way ANOVA to know the characteristics of peak plantar pressure during walking with different the facilities. In young adults, COP pathway during stairs climbing was slightly shorten and trended to abduct at forefoot. COP pathway during ramp climbing was also shorten but trend to adduct at forefoot. Peak plantar pressure of 2-3 metatarsal head and heel during ramp climbing was more decreased than level walking. In elderly people, COP pathway during stairs climbing was more shorten and abducted than leve walking and COP pathway during ramp climbing was more unstable than level walking. Peak plantar pressure of first metatarsal head increased at stair climbing and decreased at ramp climbing. That of second metatarsal head and heel was more decreased at ramp climbing. Conclusionally, Peak plantar pressures of each foot region generally increased and more changed during ramp climbing.

• 대한공업교육학회지
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• v.34 no.2
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• pp.363-378
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• 2009

The objective of the paper is to design and produce a walking robot such as humanoid robot under the given design requirements and constraints. An approach to design and produce walking robot with 2 legs was suggested. It is walking robot of 5 joints which have both of ankles, both of knee joint, and pelvis. It has 5 degrees of freedom and moves by only rotations. We review the key points before the design of the walking robot. The walking robot is consisted of 2 portions : motor and frame, control board. Final goal is to walk stably and if it detects and cognizes a special object, the walking robot avoids it and moves in other direction. The walking robot was made according to design procedures and tested by proposed algorithms. The running test was successful under given 4 modes. The findings of this research could think kinds of technologies concurrently and approach synthetically through process of design and production.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.503-515
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• 2011

We developed a walking-assistance robot for walking rehabilitation and assessed the kinematic characteristics of a prototype. The walking-assistance robot is composed of hip, knee, and ankle joints, and each joint is driven by a motor with a decelerator. The equations of angular displacement while walking were derived by theoretically analyzing human locomotion, and the calculated angular displacements were then applied to the robot controller. The output angular displacement of each joint was measured and compared with its input angular displacement in walking experiments on a treadmill at various walking speeds and strides. The differences between the input and output angular displacements are 5.22% for the hip and 2.97% for the knee joints, and it has been confirmed that the walking-assistance robot works well.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.277-280
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• 2004

In the research of biomechanical engineering, robotics and neurophysiology, to clarify the mechanism of human bipedal walking is of major interest. It serves as a basis of developing several applications such as rehabilitation tools and humanoid robots Nevertheless, because of complexity of the neuronal system that Interacts with the body dynamics system to make walking movements, much is left unknown about the details of locomotion mechanism. Researchers were looking for the optimal model of the neuronal system by trials and errors. In this paper, we applied Genetic Programming to induce the model of the nervous system automatically and showed its effectiveness by simulating a human bipedal walking with the obtained model.

• Transactions of the KSME C: Technology and Education
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• v.1 no.2
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• pp.153-165
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• 2013

The established gait analysis studies have regarded leg as one single spring. If we can design a knee-ankle actuating mechanism as a primary actuator for supporting knee extension, it might be possible to revolutionary store or release elastic strain energy, which is consumed during the gait cycle, and as a result leg stiffness is expected to increase. An ankle joint actuating mechanism that stores and releases the energy in ankle joint is expected to support and solve excessive artificial leg stiffness caused by the knee actuator (primary actuator) to a reasonable extent. If unnecessary kinematic energy is released with the artificial speed reduction control designed to prevent increase in gait speed caused by increase in time passed, it naturally brings question to the effectiveness of the actuator. As opposed to the already established studies, the authors are currently developing knee-ankle two actuator system under the concept of increasing lower limb stiffness by controlling the speed of gait in relative angular velocity of the two segments. Therefore, the author is convinced that compensatory mechanism caused by knee actuating must exist only in ankle joint. Ankle joint compensatory mechanism can be solved by reverse-examining the change in metatarso-phalangeal joint (MTPJ) tilt angle (${\theta}_1=0^{\circ}$, ${\theta}_2=17^{\circ}$, ${\theta}_3=30^{\circ}$) and the effect of change in gait speed on knee activity.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.1-9
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• 2008

The purpose of this study was to investigate the effect of different obstacle heights on the plantar foot pressure during obstacle crossing. Sixteen healthy adults who had no musculoskeletal disorders were instructed to perform unobstructed level walking and to step over obstacles corto 10cm, 20cm, 30cm. Plantar foot forces and pressures were recorded by the Footmat system(Tekscan, Boston, USA) during level and obstacle walking with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region, one heel region. One-way ANOVA was used to compare each region data of foot according to various heights. The results indicated that there are significant differences on peak pressure and maximal forces regarding each region at stance phase. As height of obstacle became high, the pathway of COP had a tendency to be short and abducted. Plantar pressure of foot could be changed by obstacle height and these findings demonstrated that obstacle with different height have an effect on structure and function of the foot.