• 제어로봇시스템학회논문지
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• 제19권4호
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• pp.334-340
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• 2013

Using a relationship between step length and accelerometer output, step length can be estimated. In this paper, we propose a new step length estimation algorithm, which can be used both for the plane and the slope by compensating the slope angle. The slope angle is estimated using a barometer and the slope angle is compensated by observing how the slope affects the step length estimation. The proposed algorithm is verified using five adult man walking data, where the average length error is about 3% regardless of the slope.

• Journal of Biosystems Engineering
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• 제34권1호
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• pp.57-62
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• 2009

Kinematic analysis of MTC (Muscle-Tendon Complex) units is a key indicator for diagnosis of patients with musculoskeletal disorders because the contracture or shortening of musculo-tendinous units is known to produce pathological gaits. Therefore, the principal objective of this study was to assess the length change in the triceps surae prior to and after wearing an AFO (Ankle-Foot Orthoses) in patients with musculoskeletal disorders during a gait. In this study, analyses were conducted using a Muscle Tendon Complex model coupled with the trajectory data from markers attached to anatomical landmarks. As a result, the maximum length change in the triceps surae during a gait was 4.87% when a barefoot walking group and a walking group with AFO were compared. In particular, the difference in length changes between both groups in Soleus MTC units was found to be statistically significant in all gait phases. Our results revealed that MTC length in the AFO walking group was clearly increased over that of the barefoot walking group. In the future, further studies will be required in order to more adequately assess musculoskeletal disorders using many cases studies with regard to agricultural working conditions because this study deals with the kinematic analysis of musculo-tendinous units in the case of clinical experiments.

• 한국정보통신학회논문지
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• 제16권6호
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• pp.1235-1241
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• 2012

본 논문에서는 4족 보행로봇 TITAN-VIII의 모든 관절각과 로봇 본체의 자세각을 계측하여 발바닥의 위치를 추정하고 각 관절의 구동모터를 제어하였다. 네 발바닥에 로드셀을 설치하여 주기, 한주기당 이동거리와 발바닥이 들어 올려지는 높이를 변경하여 8가지 서로 다른 조건에서 보행실험을 수행하고 보행 중 발바닥에 가해지는 힘과 각 관절을 구동하는 모터의 소비전력을 구한 후 비교 분석하여 자세제어의 타당성을 평가하였다. 분석결과 새로운 주기가 시작되는 구간에서 발바닥이 지면을 늦게 떠나는 슬립현상을 확인했는데 이것은 관절각과 본체의 자세각을 계측하여 발바닥의 위치를 추정하고 보행계획을 수립하여 제어하는 것만으로 보행 중 발생하는 로봇 본체의 기울어짐과 기계적인 에러를 완벽하게 극복하지 못함을 확인했다.

• KIEAE Journal
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• 제14권4호
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• pp.91-96
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• 2014

The behavior of walking involves our action of seeing things. It is the intention of this research that the cognitive process of perceiving things along the path can affect the way we sense the length of the journey. The theory generally accepted in this line of thought is the 'feature accumulation theory'. It assumes that if the journey includes many objects or memorable features, then our memory recalls that journey much farther than it really was. This study set up a real-life experiment by asking university students about their mental memory of the two different routes in the campus. One is a longer path that has not much to look at except trees and the other a shorter path yet with many buildings, sign boards and street furnitures. The subjects processed their mental image in the brain based on their experience. They showed a strong tendency that the path with more features were remembered longer while that with less features shorter. More interestingly, it was found that as their experience increases, they become more accurate about the exact length of the questioned paths. The result corroborates the theory that human perception of space is based on the topological understanding of surroundings rather than geometric understanding.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.1062-1065
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• 2002

We have evaluated the ability of a time-delayed artificial neural network (TDANN) to predict muscle forces using only eletromyographic(EMG) signals. To achieve this goal, tendon forces and EMG signals were measured simultaneously in the gastrocnemius muscle of a dog while walking on a motor-driven treadmill. Direct measurements of tendon forces were performed using an implantable force transducer and EMG signals were recorded using surface electrodes. Under dynamic conditions, the relationship between muscle force and EMG signal is nonlinear and time-dependent. Thus, we adopted EMG amplitude estimation with adaptive smoothing window length. This approach improved the prediction ability of muscle force in the TDANN training. The experimental results indicated that dynamic tendon forces from EMG signals could be predicted using the TDANN, in vivo.

• 한국의류산업학회지
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• 제8권1호
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• pp.99-106
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• 2006

With the growing interest in pet dogs and pet dog's wear I used this study to compare and analyze the pattern used by each supplier and developed a new pattern for pet dogs' wear which is appropriate for pet dogs' body lines and movement. Test subjects were 91 pet dogs in Busan and after comparing 3 patterns from different suppliers, I developed the pattern reflecting pet dogs' body shapes and movement. Results are as follows; 1) As a result of analyzing measurements, it was found that pet dogs motion in walking on four feet, is different from that of people on two feet. For center measurements, their waist to bust length is longer than their waist to back length. The result of analysis shows that bust circumference impacts most other measurement results and it seems that better results are achieved if the bust line is taken into consideration when measuring bust back length, bust front length, neck base circumference, front leg arc, the length between lateral shoulder etc. 2) As a result of comparing suppliers' patterns, it was discovered that each supplier has different sizes for the same patterns and those sizes are not standardized across the board. Even if the same size of pattern was actually used in the production of pet dogs' wear by the individual companies, there were many variations in size for each item. 3) To develop a more standard pattern of pet dogs' wear, I collected and analyzed 3 patterns from each supplier and designed a new pattern, revising it three times. After test-wearing of the experimental pattern and the studied patterns, and comparing and analyzing the results, the studied pattern had similarly better estimation than the experimental one.

• 한국콘텐츠학회논문지
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• 제8권4호
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• pp.273-284
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• 2008

동작은 유아의 신체적, 사회적, 인지적 발달에 매우 중요한 요소이다. 본 논문에서는 유아의 신체에 적절한 동작 추정 방법을 제안한다. 본 논문에서는 동작교육에 필요한 동작 중에서 걷기, 뛰기, 앙감질의 이동동작과 구부리기, 뻗기, 균형잡기, 회전하기의 비이동 동작을 대상으로 한다. 제안된 시스템은 두 대의 카메라에서 획득된 프레임에서 조명 보정, 배경 제거, 모폴로지 실행 등의 과정을 통해 실루엣을 추출한다. 실루엣 특징으로 면적, 가로세로 비율, 발의 위치, 7개의 Hu moments를 사용한다. 또한 지역 특징으로 실루엣을 $5{\times}3$으로 나누어 각 영역의 면적과 움직임을 사용한다. 동작 추정을 위해서, 추출된 특징에 확률 전파를 적용하였다. 본 논문에서 제안된 알고리즘은 마커없이 유아들의 기본 동작을 추정함으로써 동작교육을 위한 가상 학습공간에서 실감형 인터페이스로 사용될 수 있는 가능성을 보여주고 있다.