• 한국정보통신학회논문지
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• 제26권8호
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• pp.1165-1171
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• 2022

가속도 센서를 이용한 인간의 행동인식은 다양한 분야에 적용되고 있다. 스마트폰의 보급이 일반화되면서 스마트폰에 내장된 가속도 센서를 이용한 인간의 행동인식 방법이 연구되고 있다. 노인의 경우 넘어지게 되면 심각한 부상으로 이어지는 경우가 많으며 공사 현장에서도 넘어짐은 중요한 사고원인 중 하나이다. 본 연구는 스마트폰에 내장된 가속도 센서와 방향 센서를 이용하여 사람의 넘어지는 방향에 대해 연구하였다. 기존에는, 인간의 행동을 인식하기 위해서 가속도벡터의 크기를 활용하는 것이 일반적인 방법이었다. 본 연구는 최근 많이 활용되고 있는 딥러닝 기법을 적용하여 인간의 넘어지는 방향을 인식하는 방법을 제안하였다.

• 한국통신학회논문지
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• 제34권7B호
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• pp.721-727
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• 2009

무선 센서 네트워크(WSN)에서는 저가 및 저 전력 센서를 활용하기 때문에 센서의 업무를 성공적으로 수행하면서 적은 에너지를 소모하는 것이 중요한 문제로 부각 된다. 기존의 계층척 WSN 알고리즘들에서 나타나는 제한점은 데이터 진행방향에 대한 역방향 전송이 이루어 질수 있다는 것이다. 본 논문은 데이터 방향성을 고려한 DDACM(Data Direction Aware Clustering Method) 방법을 제안한다. 데이터 역방향 전송 방지를 위해 클러스터헤더는 데이터 전송 방향에서 싱크노드와 가장 가까운 노드가 먼저 임명되고, 에너지 레벨이 일정량 이하 시 클러스터 헤더를 교체하는 방법융 제안한다. 실험을 통하여 LEACH(Low Energy Adaptive Clustering Hierarchy)방식과 비교하여 데이터 역방향 전송올 최소화하여 에너지 소모를 줄일 수 있음을 확인하였다.

• 센서학회지
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• 제32권5호
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• pp.307-312
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• 2023

To measure the flow velocity and direction in the near field of an unmanned underwater vehicle, an optical measurement unit containing an image sensor and a phosphor-integrated pillar that mimics the neuromasts of a fish was constructed. To analyze pillar movement, which changes with fluid flow, fluorescence image analysis was conducted. To analyze the flow velocity, mean force analysis, which could determine the relationship between the light intensity of a fluorescence image and an external force, and length-force analysis, which could determine the distance between the center points of two fluorescence images, were employed. Additionally, angle analysis that can determine the angles at which pixels of a digital image change was selected to analyze the direction of fluid flow. The flow velocity analysis results showed a high correlation of 0.977 between the external force and the light intensity of the fluorescence image, and in the case of direction analysis, omnidirectional movement could be analyzed. Through this study, we confirmed the effectiveness of optical flow sensors equipped with phosphor-integrated pillars.

• 한국정밀공학회지
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• 제20권7호
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• pp.105-113
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• 2003

This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously, for stably grasping an unknown object. In order to safely grasp an unknown object using the robot's gripper, it should measure the force in the gripping direction and the force in the gravity direction, and perform the force control using the measured forces. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of made sensor was performed. and the result shows that interference errors of the developed sensor are less than 3%. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object was performed using it. The fabricated gripper could grasp an unknown object stably. Thus, the developed 6-axis robot's finger force/moment sensor may be used for robot's gripper.

• 한국정밀공학회지
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• 제25권7호
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• pp.79-86
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• 2008

This paper describes the development of wearing intelligent shoe system to measure applied forces and moments (ground reaction forces and moments) on the soles of feet during human walking. In order to walk safely, robot must get the intelligent feet with 6-axis force/moment sensors (Fx sensor (x-direction force sensor), Fy sensor, Fz sensor, Mx sensor (Mx : x-direction moment sensor), My sensor, and Mz sensor) and detect the forces and moments data from the sensors. And the feet must be controlled with the data and controllers. While a human is walking, the forces and moments should be measured and analyzed for robot's intelligent feet. Therefore, the wearing intelligent shoe system should be developed. In this paper, four 6-axis farce/moment sensors and two high speed measuring devices were designed and fabricated, and the wearing intelligent shoe system was made using these. The characteristic tests of the wearing intelligent shoe system were performed, and the forces and moments were detected using it.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.387-390
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• 1993

The most important technique for an indoor robot navigation is to find out the direction and the distance from the current location to the destination through the information achieved from the sensor. For this purpose, we suggest sensor-based local homing method which compares the destination sensory data with the current location. As for the sensors, we use the CCD camera and the ultrasonic sensor, and recorded entire 360 degree panoramic data. We match the features of the image data, and the distance and the direction of the matched point will be considered as fuzzy numbers. Through a simple fuzzy arithmetic, we infer the geometric relations between the current location and the destination location.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.672-676
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• 2004

In this paper, measuring system of 5 DOF motion errors are proposed using two capacitive type sensor, a straight edge and a laser interfoerometer. Yawing error and pitching error are measured using the laser interferometer, and rolling error is measured by the reversal method using a capacitive type sensor. Linear motion errors of horizontal and vertical direction are measured using the sequential two point method. In this case, influence of angular motion errors is compensated using the previously measured angular motion errors. In the horizontal direction, measuring accuracy is within 0.05 $\mu$m and 0.27 arcsec, and in the vertical direction, it is within 0.15 $\mu$m and 0.5 arcsec. From these results, it is confirmed that the proposed measureing system is very effective to the measurement of 5 DOF motion errors in the ultra precision feed tables.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.672-675
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• 2001

본 논문에서 Interpolation Methods를 이용하여 보다 정화한 풍속을 계산하는 방법과 보다 정확한 풍향을 계산하기 위하여 Interpolation Polynomial을 찾는 방법을 제안하였고, 이렇게 제안된 방법을 이용하여 3-Cup Anemometer의 성능을 개선하였다. 우리는 풍향, 풍속의 관측을 위해 기구부는 3-cup Type Anemometer로, 전자부는 Photo Sensor를 이용하여 구현하였다. 정확한 풍속과 풍향의 측정을 위해서는 시스템의 메모리 한계 및 성능을 고려한 시스템 설계와 8비트 Gray Code Film으로 256(= 2$^{8}$ )개의 각도 Data로 360$^{\circ}$를 표현하는 방법이다.

• 제어로봇시스템학회논문지
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• 제11권2호
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• pp.122-126
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• 2005

A technique for alignment to true north is presented based on synchronized measurements of vision image by a camera and output voltage of wind direction sensor. The true wind direction is evaluated by means of image processing techniques with least square sense, and then evaluated true value is compared with measured output voltage of the sensor. The uncertainty analysis about the component error for the proposed method in practical situation is performed. The proposed technique is applied to real meteorological tower (wind measuring tower) at the Daekwanryung test site. In addition, some uncertainty analysis of this method is presented.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권9호
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• pp.526-532
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• 2003

This paper describes a recognition method of a road direction for an autonomous vehicle based on magnetic sensors. Using the sensors mounted on a vehicle and the magnetic markers embedded along the center of road, the autonomous vehicle can recognize a road direction and control a steering angle. Using the front lateral deviation of a vehicle and the rear one, the road direction is calculated. The analysis of magnetic field, the acquisition technique of training data, the training method of neural network and the computer simulation are presented. According to the computer simulation, the proposed method is simulated, and its performance is verified. Also, the experimental test is confirmed its reliability.