• 한국생산제조학회지
• /
• 제18권5호
• /
• pp.521-528
• /
• 2009

In these days, biomimetic apprioach in the design and control of robotic system has drawn much attention. The human-being and mammals possess their own feet. Using the mobility of their feet, they are able to walk in various environments such as plain land, desert, swamp, and so on. Previously developed biped robots and four-legged robots did not employ such adaptable foot. In this work, a biomimetic foot mechanism is investigated through analysis of the foot structure of the human-being. This foot mechanism consists of a toe, an ankle, a heel, and some springs replacing the foot muscles and tendons. Using five toes and springs, this foot can adapt to various environments. A mathematical modeling for this foot mechanism was performed and its characteristics were observed through numerical simulation.

• 한국지능시스템학회논문지
• /
• 제22권3호
• /
• pp.347-352
• /
• 2012

본 논문에서는 보행 로봇을위한 트러스 구조의 로봇 발 메커니즘을 제시한 후, 제시된 로봇 발 메커니즘의 특성을 분석하였다. 제시된 로봇 발 메커니즘은인간의 발의 구조적인 특징을 관찰하여 모델링 되었다. 특히, 인간의 발에 사용되고 있는 뼈대는 트러스로 나타내었고, 뼈대에 연결되어 있는 다양한 인대는 간단한 강성 요소로서 나타내었다. 따라서 이러한 로봇 발은 보행 로봇이 발걸음을 옮기는 과정에서 발에 작용되는 충격을 완화시킬 수 있는 장점을 갖는다. 결과적으로, 제안된 로봇 발 메커니즘은 보행로봇의 보행피로를 줄이는데 기여할 수 있다.

• 한국지능시스템학회논문지
• /
• 제23권1호
• /
• pp.12-17
• /
• 2013

본 논문에서는 컴플라이언스 특성의 발을 갖는 이족 로봇의 다리 메커니즘을 제시한 후, 이족 로봇을 위한 전형적인 보행 패턴에서 발의 접촉 반발력과 이것이 무릎과 힙 관절에 미치는 영향을 고찰하고자 한다. 이러한 분석은 보행 로봇이 걸음 동작을 수행할때, 발의 물리적인 접촉력의 영향을 파악하는데 있어서 유용하고, 다리 메커니즘의 관절 사양을 결정하는데 활용될 수 있다. 결과적으로, 로봇 발 메커니즘의 컴플라이언스 특성이 발의 접촉 반발력에 의해 영향을 받는 보행 다리 관절의토오크 특성을 완화시키는데 기여할 수 있음을 보인다.

• 로봇학회논문지
• /
• 제12권2호
• /
• pp.161-172
• /
• 2017

Foot mechanisms play the role of interface between the main body of robotic systems and the ground. Biomimetic design of the foot mechanism is proposed in the paper. Specifically, multi-chained and multiple contact characteristics of general foot mechanisms are analyzed and their advantages are highlighted in terms of impulse. Using Newton-Euler based closed-form external and internal impulse models, characteristics of multiple contact cases are investigated through landing simulation of an articulated leg model with three kinds of foot. It is shown that in comparison to single chain and less articulated linkage system, multi-chain and articulated linkage system has superior characteristic in terms of impulse absorption as well as stability after collision. The effectiveness of the simulation result is verified through comparison to the simulation result of a commercialized software.

• Structural Engineering and Mechanics
• /
• 제66권1호
• /
• pp.1-14
• /
• 2018

Column is usually floating on the stone base directly with or without positioning tenon in traditional Chinese timber structure. Vertical load originated by the heavy upper structure would induce large friction force and compression force between interfaces of column foot and stone base. This study focused on the mechanical behaviors of column foot joint with consideration of the influence of vertical load. Mechanism of column rocking and stress state of column foot has been explored by theoretical analysis. A nonlinear finite element model of column foot joint has been built and verified using the full-scale test. The verified model is then used to investigate the mechanical behaviors of the joint subjected to cyclic loading with different static vertical loads. Column rocking mechanism and stress distributions of column foot were studied in detail, showing good agreement with the theoretical analysis. Mechanical behaviors of column foot joint and the effects of the vertical load on the seismic behavior of column foot were studied. Result showed that compression stress, restoring moment and stiffness increased with the increase of vertical load. An appropriate vertical load originated by the heavy upper structure would produce certain restoring moment and reset the rocking columns, ensuring the stability of the whole frame.

• 한국CDE학회지
• /
• 제22권2호
• /
• pp.6-10
• /
• 2016

This paper presents the kinematics of a walking robot leg based on Jansen mechanism. By using simple mathematics, all trajectories of walking robot leg links can be calculated. A foot point trajectory is used to evaluate the performance of a walking robot leg. Trial and Error method is used to find a best combination of link lengths under certain restrictions. All simulations are performed by Matlab. Ground score, drag score, step size, foot lift, instant speed, and average speed of foot point trajectories are used for selecting the best one.

• KSTLE International Journal
• /
• 제7권2호
• /
• pp.51-55
• /
• 2006

In order to design an effective foot surface which can provide adequate friction for a self-propelled medical microrobot moving inside the small intestine, frictional mechanisms between the small intestine inner wall and the foot surface of the robot must be understood. In this paper, mechanical interlocking effect was considered to design the surface of the foot that can generate the desired frictional force. The concept of the design was derived from the hookworm that lives inside the small intestine. Hookwarms are known to adhere to the small intestine wall by interlocking with villi on the surface of the small intestine. The interlocking mechanism was considered as the main frictional mechanism for the design of the microrobot foot surface in this work. 2 mm and 6 mm diameter solid and hollow cylindrical shaped foot specimens were designed and tested to assess the frictional force between the specimens and the porcine small intestine specimen.

• EDISON SW 활용 경진대회 논문집
• /
• 제5회(2016년)
• /
• pp.424-428
• /
• 2016

This paper presents the kinematics of a walking robot leg based on Jansen mechanism. By using simple mathematics, all trajectories of walking robot leg links can be calculated. A foot point trajectory is used to evaluate the performance of a walking robot leg. Trial and Error method is used to find a best combination of link lengths under certain restrictions. All simulations are performed by Matlab. Ground score, drag score, step size, foot lift, instant speed, and average speed of foot point trajectories are used for selecting the best one.

• 대한족부족관절학회지
• /
• 제18권3호
• /
• pp.124-128
• /
• 2014

Purpose: The purpose of this study was to assess the treatment outcomes and prognosis of Lisfranc joint fracture and dislocation according to the mechanism of injury and treatment method. Materials and Methods: Twenty six patients with Lisfranc fracture-dislocation who had been treated surgically were included in this retrospective study. The patients were divided into two groups according to mechanism of injury: direct crushing injury (16 patients) and indirect rotational or compressive injury (10 patients). The patients were also divided into three groups according to the surgical methods. The parameters used were radiographic evaluation, patients' subjective satisfaction levels, length of hospital stay, and the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score. Statistical analysis was performed. Results: The mean postoperative AOFAS midfoot score was 78.7. The mean length of stay was 39.6 days. Statistically significant differences in subjective satisfaction, AOFAS midfoot score, and length of hospital stay were observed between the two groups (p<0.05). However, no significance differences were observed between the three groups who were divided according to the different surgical methods (p>0.05). Conclusion: Mechanism of trauma and the severity of soft-tissue injury were significant prognostic factors affecting the surgical outcomes of Lisfranc joint fracture and dislocation.

• Journal of Astronomy and Space Sciences
• /
• 제28권1호
• /
• pp.79-91
• /
• 2011

Ongnu (Jade Clepsydra; also called Heumgyeonggaknu) is a water clock was made by Jang Yeong-sil in 1438. It is not only an automatic water clock that makes the sound at every hour on the hour by striking bell, drum and gong, but also an astronomical clock that shows the sun's movement over time. Ongnu's power mechanism used is a water-hammering method applied to automatic time-signal device. The appearance of Ongnu is modeled by Gasan (pasted-paper imitation mountain) and Binpungdo (landscape of farming work scene) is drawn at the foot of the mountain. The structure of Ongnu is divided into the top of the mountain, the foot of the mountain and the flatland. There located are sun-movement device, Ongnyeo (jade female immortal; I) and Four gods (shaped of animal-like immortals) at the top of the mountain, Sasin (jack hour) and Musa (warrior) at the foot of the mountain, and Twelve gods, Ongnyeo (II) and Gwanin on the flatland. In this study, we clearly and systematically understood the time-announcing mechanism of each puppet. Also, we showed the working mechanism of the sun-movement device. Finally, we completely established the 3D model of Ongnu based on this study.