• 로봇학회논문지
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• 제14권4호
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• pp.270-277
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• 2019

Inspired by small insects, which perform rapid and stable locomotion based on body softness and tripod gait, various milli-scale six-legged crawling robots were developed to move rapidly in harsh environment. In particular, cockroach's leg compliance was resembled to enhance the locomotion performance of the crawling robots. In this paper, we investigated the effects of changing leg compliance for the locomotion performance of the small light weight legged crawling robot under various payload condition. First, we developed robust milli-scale six-leg crawling robot which actuated by one motor and fabricated in SCM method with light and soft material. Using this robot platform, we measured the running velocity of the robot depending on the leg stiffness and payload. In result, there was optimal range of the leg stiffness enhancing the locomotion ability at each payload condition in the experiment. It suggests that the performance of the crawling robot can be improved by adjusting stiffness of the legs in given payload condition.

• 한국전자통신학회논문지
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• 제10권3호
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• pp.395-402
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• 2015

본 논문에서는 곤충형 다리 구조를 갖는 4족 로봇의 정적 계단 보행 시 계단과의 충돌 제약이 없는 효율적인 걸음새 궤적 생성 방법을 제안한다. 우선 4족 로봇의 순기구학 및 역기구학 모델을 각기 대수학적 방법과 기하학적 방법으로 유도한다. 제안한 방법에서는 보행 시작 위치에서 수직 상승 후 사인 파형의 계단 보행 궤적을 생성하고, 계단과의 충돌을 피하기 위한 보행 궤적의 계수를 설정한다. 또한 안정적인 계단 보행을 위한 걸음새 순서를 결정한다. 마지막으로, 컴퓨터 시뮬레이션을 통해 제안한 계단 보행 방법의 효용성 및 실제 적용 가능성을 검증한다.

• 로봇학회논문지
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• 제7권4호
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• pp.259-266
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• 2012

In these days, researches about underwater robots have been actively in progress for the purposes of ocean detection and resource exploration. Unlike general underwater robots such as ROV(Remotely Operated Vehicle) and AUV(Autonomous Underwater Vehicle) which have propellers, an articulated underwater robot which is called Crabster has been being developed in KORDI(Korea Ocean Research & Development Institute) with many cooperation organizations since 2010. The robot is expected to be able to walk and swim under the sea with its legs. Among many researching fields of this project, we are focusing on a swimming section. In order to find effective swimming locomotion for the robot, we approached this subject in terms of Biomimetics. As a model of optimized swimming organism in nature, diving beetles were chosen. In the paper, swimming motions of diving beetles were analyzed in viewpoint of robotics for applying them into the swimming motion of the robot. After modeling the kinematics of diving beetle through robotics engineering technique, we obtained swimming patterns of the one of living diving beetles, and then compared them with calculated optimal swimming patterns of a robot leg. As the first trial to compare the locomotion data of legs of the diving beetle with a robot leg, we have sorted two representative swimming patterns such as forwarding and turning. Experimental environment has been set up to get the motion data of diving beetles. The experimental equipment consists of a transparent aquarium and a high speed camera. Various swimming motions of diving beetles were recorded with the camera. After classifying swimming patterns of the diving beetle, we can get angular data of each joint on hind legs by image processing software, Image J. The data were applied to an optimized algorithm for swimming of a robot leg which was designed by robotics engineering technique. Through this procedure, simulated results which show trajectories of a robot leg were compared with trajectories of a leg of a diving beetle in desired directions. As a result, we confirmed considerable similarity in the result of trajectory and joint angles comparison.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.101-102
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• 2007

• 한국전자통신학회논문지
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• 제10권9호
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• pp.1039-1048
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• 2015

본 논문에서는 곤충형 다리 구조를 갖는 4족 로봇의 효율적인 계단 보행을 위해 유전 알고리즘(Genetic Algorithm: GA)에 기반한 계단 보행 방법을 제안한다. 제안한 방법에서는 우선 계단 보행을 위한 요소와 도달 영역을 정의한다. 또한 GA 수행을 위한 유전자와 적합도 함수를 설정하고, GA를 이용하여 최소 이동 거리와 최적 에너지 안정도 여유(Energy Stability Margin: ESM)을 갖는 4족 로봇의 착지 지점을 탐색하여 걸음새 궤적을 생성한다. 마지막으로, 컴퓨터 시뮬레이션을 통해 본 논문에서 제안한 계단 보행 방법의 효용성 및 우수성을 검증한다.

• 로봇학회논문지
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• 제14권4호
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• pp.264-269
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• 2019

This paper presents mechanical design and control of a bio-inspired legged robot. To achieve a fast legged running mechanism, a novel linkage leg structure is designed based on hind legs of domestic cats. The skeletomuscular system and parallel leg movement of a cat are analyzed and applied to determine the link parameters. The hierarchical control architecture is designed according to the biological data to generate and modulate desired gaits. The effectiveness of the leg mechanism design and control is verified experimentally. The legged robot runs at a speed of 46 km/h, which is comparatively higher speed than other existing legged robots.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.467-470
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• 1990

This thesis presents a simple heuristic algorithm which can be applied. to a quadruped wafting vehicle for increasing the terrain adaptability. The proposed method controls a leg length which is in tranfer phase to maintain initial orientation of the robot body by using FSR type force sensors attached to foot-tips. Also, some basic experiments using the vehicle are performed to demonstrate the effectiveness of the algorithm.

• Animal Bioscience
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• 제37권4호
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• pp.555-566
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• 2024

Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.831-836
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• 2007

This paper proposes an optimal galloping trajectory which costs low energy and guarantees the stability of the quadruped robot. In the realization of the fast galloping, the trajectory design is important. As a galloping trajectory, we propose an elliptic leg trajectory, which provides simplified locomotion to complex galloping motions of animals. However, the elliptic trajectory, as an imitation of animal galloping motion, does not guarantee stability and minimal energy consumption. We propose optimization based on the energy and stability using a genetic algorithm, which provides the robust and global solution to a multi-body, highly nonlinear dynamic system. To evaluate and verify the effectiveness of the proposed trajectory, computer simulations were carried out.

• 한국정밀공학회지
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• 제13권11호
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• pp.152-162
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• 1996

A four-legged Walking Machine can move on the plain terrain with mobility and stability and stability, but if there exist any obstacles on the terrain of the motion direction, it takes extra time to cross those obstacles and the stability should be considered during motion. The main objective is the study a Quadruped which can cross obstacles with better mobility, stability and fuel economy than any other wheeled or tracked vehicles. Vertical step, isolated wall and ditch are the basic obstacles and by understanding those three cases perfectly, a Quadruped can move on any mixed rough terrain as 4-legged terrestrial vertebrates move. Each leg of a Quadruped has a limited walk space called a walking volume and this is very important to deter- mine the crossing capability in a static analysis. A Quadruped can be simplified with links and joints. By applying the research method, a quadruped can determine the control procedures as soon as it receives the terrain information from scanner and finally can move with mobility and stability.