• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.923-926
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• 2000

This paper concerned with the patterns of foot-floor contact and electromyography activities of the lower extremity of the body during the termination of human gait. The termination of human gait is defined as the transition from a steady-state gait to a quiet standing posture. The transition between these two states has not been extensively studied and defined. There appears to be a critical period in the gait cycle that the decision to terminate gait or continue to take an additional step must be made.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.83-84
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• 2011

• ETRI Journal
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• 제35권6호
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• pp.1029-1037
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• 2013

This paper introduces a novel and fast synthesizing method for 3D motions of quadrupedal animals that uses only a small set of motion capture data. Unlike human motions, animal motions are relatively difficult to capture. Also, it is a challenge to synthesize continuously changing animal motions in real time because animals have various gait types according to their speed. The algorithm proposed herein, however, is able to synthesize continuously varying motions with proper limb configuration by using only one single cyclic animal motion per gait type based on the biologically driven Froude number. During the synthesis process, each gait type is automatically determined by its speed parameter, and the transition motions, which have not been entered as input, are synthesized accordingly by the optimized asynchronous motion blending technique. At the start time, given the user's control input, the motion path and spinal joints for turning are adjusted first and then the motion is stitched at any speed with proper transition motions to synthesize a long stream of motions.

• 한국지능시스템학회논문지
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• 제16권3호
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• pp.266-270
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• 2006

본 논문에서는 은닉 마르코프 모델을 바탕으로 하는 발걸음을 이용한 개인 식별 시스템을 제안한다. 개인의 발걸음은 연속적인 자세나 움직임의 집합으로 나타낼 수 있는데, 구조적으로 연속적인 움직임의 변화는 확률적인 특성을 가지고 있기 때문에 은닉 마르코프 모델을 이용하여 적절하게 모델링 할 수 있다. 개인의 발걸음은 N개의 이산적인 자세 간의 전이로 이루어졌다고 가정하였으며, 이를 계산하기 위해 MMSI라는 발걸음 특징 모델을 제안하였다. MMSI는 발걸음 인식에 중요한 역할을 하는 시공간적인 정보를 가지고 있는 그레이-스케일 영상이다. 실험 결과는 MMSI를 이용하여 은닉 마르코프 모델을 바탕으로 한 발걸음 인식 결과를 보여준다.

• 제어로봇시스템학회논문지
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• 제9권11호
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• pp.943-951
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• 2003

A strategy for fault-tolerant gaits of autonomous legged robots is proposed. A legged robot is considered to be fault tolerant with respect to a given failure if it is guaranteed to be capable of walking maintaining its static stability after the occurrence of the failure. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but legged robots have fault tolerance capability to continue static walking. An algorithm for generating fault-tolerant gaits is described and, especially, periodic gaits are presented for forward walking of a hexapod robot with a locked joint failure. The leg sequence and the formula of the stride length are analytically driven based on gait study and robot kinematics. The transition procedure from a normal gait to the proposed fault-tolerant gait is shown to demonstrate the applicability of the proposed scheme.

• The Journal of Korean Physical Therapy
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• 제23권5호
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• pp.49-56
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• 2011

Purpose: The purpose of this study was to investigate the kinematic characteristics and muscle activities during the following two conditions: transition from half-kneel to standing on the affected leg and non-affected leg. Methods: Twenty-one hemiplegic patients participated in the study. A motion analysis system was used to record the range of motion and angle velocity of the hip, knee and ankle from the half-kneel to the standing position. Electromyography was used to record the activity of 4 muscles. Results: The statistical analysis showed that the minimum ROM of the hip joint was less on the affected leg during transition from half-kneel to standing. However, the minimum ROM of the knee and ankle joints was less on the non-affected leg during transition from half-kneel to standing. The angle velocity of the knee and ankle joints was less during transition from half kneeling to standing on the non-affected leg. Muscle activity of the rectus femoris and tibialis anterior was less while moving from half-kneel to the standing position on the affected leg. Conclusion: These results show that greater active ROM of the knee and ankle was required on the affected leg for transition from half-kneel to the standing position than for normal gait. Muscle activity of the rectus femoris and tibialis anterior is normally required for movement from the half-kneel to the standing position during normal gait. Further studies are needed to investigate the antigravity movement in healthy subjects and hemiplegic patients in order to completely understand the normal and abnormal movement from the half-kneel to the standing position.

• 웰빙융합연구
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• 제5권1호
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• pp.1-7
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• 2022

Purpose: This study aimed to investigate spatial and temporal features of motor control in an individual with hemiparesis during the curvilinear gait (CG) and proposed an exercise guideline. Research design, data and methodology: An individual aged 63 with hemiparesis by stroke disease was participated in the study. Autoencoder (AE) was used to extract four motor modules from eight muscle activities of the paretic leg during CG. After extraction, each module of four modules was operationally defined by numbering from M1 to M4 according to spatial and temporal features and compared with results reported in a previous study. Results: As a result, an individual with hemiparesis had motor module problems related to difficulty of weight acceptance (module 1), compensation for the weakness of ankle plantar flexor (module 2), a spastic synergistic pattern (module 3) and difficulty with transition from the swing to stance phase (module 4) in terms of spatial features. Also, a delayed activation timing of temporal motor module (module 2) related to the forward propulsion during CG was observed. Conclusions: Gait rehabilitation for the stroke will need to consider clinical significances in respect of the deterioration of motor module and provide the tailored approaches for each gait phase.

• 대한기계학회논문집A
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• 제38권9호
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• pp.989-997
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• 2014

본 논문에서는 6 족 다관절 해저로봇 크랩스터를 위한 정적 보행 알고리즘 설계 방법에 대하여 기술하였다. 정적 보행 알고리즘 설계를 위해 보행계획 벡터와 다리쌍 벡터의 개념을 도입하여 6 족 로봇 보행기법 설계의 편의성과 확장성을 확보하고, 이를 이용하여 수중환경이나 탐사조건에 따라 운용할 수 있는 여섯 가지 정적 보행기법을 설계하였다. 그리고, 공통 제어변수를 사용하여 각 보행 간 자유로운 연동과 자세제어와의 복합보행을 수행할 수 있도록 하였다. 설계된 여섯 가지 정적 보행기법은 시뮬레이션을 통하여 확인하였고, 크랩스터에 적용하여 보행기법 간 연동성과 복합보행 기능 등을 검증하였다.

• 한국전문물리치료학회지
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• 제3권3호
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• pp.32-43
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• 1996

The purpose of this case study was to introduce functional electrical stimulation(FES) for paraplegic patients. FES provides the ability to rise from sitting to standing, maintenance of a standing position, and the ability to walk with a reciprocal gait. Six channels of electrical stimulation are sufficient for synthesis of a simple reciprocal gait pattern in these patients. During the double-stance phase, knee extensor muscles of both knees are stimulated, providing sufficient support for the body. Only one knee extensor muscle group is excited during the single-stance phase. The swing phase of the contralateral lower extremity is accomplished by eliciting the synergic flexor muscle response through electrical stimulation of afferent nerves. The transition from the double-stance phase to the swing phase is controlled by two hand switches used by the therapist or built into the handles of the walking frame for using by the patient. A twenty-five years old male was with a T9/T9 spinal cord injury due to a traffic accident and admitted to Yonsei Rehabilitation Hospital for comprehensive treatment. After 30 days of training using the Parastep(R) he was able to stand for 10 minutes. After 43 days, he was able to walk and at discharged he could walk for 100 meters.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.344-351
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• 2014

In order to accomplish complex navigational commands, humanoid robot should be able to modify its walking period, step length and direction independently. In this paper, a novel walking pattern generation algorithm is proposed to satisfy these requirements. Modification of the walking pattern can be considered as a transition between two periodic walking patterns, which follows each navigational command. By assuming the robot as a linear inverted pendulum, the equations of motion between ZMP(Zero Moment Point) and CM(Center of Mass) state is easily derived and analyzed. After navigational command is translated into the desired CM state, corresponding CM motion is generated to achieve the desired state by using simple ZMP functions. Moreover, when the command is not feasible, feasible command is alternated by using binary search algorithm. Subsequently, corresponding CM motion is generated. The effectiveness of the proposed algorithm is verified by computer simulation.