• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.349-354
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• 2015

This paper is about utilizing magnetic sensor to measure magnetic signal and analyze the form of magnetic signal for vehicle detection. For magnetic sensor, MR sensor from Honeywell company was used, and Helmholtz coil of which 3 axis' length is 1.2 m was manufactured to check the capability of the sensor and estimate its ability to detect the magnetic field. Vehicle detection was performed in following steps: installing sensor in road lane and non-road lane; estimating magnetic field when the vehicle is run by the driver; and estimating magnetic field of 7 different vehicles with different sizes. Also, sensor was installed at SUV and small-sized vehicle's park and non-park area to analyze the form of magnetic field. Lastly, the form of magnetic field made by different parts of the vehicle was analyzed. Based on the analysis, the form of magnetic field's magnetic peak value was bigger for road lane than non-road lane, complicated form was useful to distinguish the road lane above the installed sensor and the location of the running car, and the types of vehicle could be sorted because the variance of the magnetic field was bigger for bigger size of the vehicle. Also, it was confirmed that the forms of vehicle in parts-by-parts estimates.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1649-1654
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• 2021

In this paper, we introduce a regularization of long short-term memory (LSTM) based fall detection system using TensorFlow that can detect falls that can occur in the elderly. Fall detection uses data from a 3-axis acceleration sensor attached to the body of an elderly person and learns about a total of 7 behavior patterns, each of which is a pattern that occurs in daily life, and the remaining 3 are patterns for falls. During training, a normalization process is performed to effectively reduce the loss function, and the normalization performs a maximum-minimum normalization for data and a L2 regularization for the loss function. The optimal regularization conditions of LSTM using several falling parameters obtained from the 3-axis accelerometer is explained. When normalization and regularization rate λ for sum vector magnitude (SVM) are 127 and 0.00015, respectively, the best sensitivity, specificity, and accuracy are 98.4, 94.8, and 96.9%, respectively.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.269-274
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• 2002

최근에 TV의 축구, 야구와 같은 스포츠 중계 방송에서 팀의 로고나 점수, 거리와 같은 그래픽 정보를 운동장에 합성시켜 보여주는 새로운 기술이 사용되고 있다. 이는 증강현실(AR: Augmented Reality)의 한 분야인 실시간 이미징 합성 기법을 사용한 것으로서 일반적으로 가상이미징 시스템이라 불리운다. 본 논문에서는 방송용 카메라의 렌즈와 팬(pan), 틸트(tilt) 축에 센서를 부착하여 이를 해석함으로써, 실시간으로 3차원 그래픽 좌표계의 가상 카메라를 제어하는 센서기반 가상이미징 시스템의 구현 결과와 관련기술을 소개한다. KBS 기술연구소에서는 실시간 가상이미징 시스템을 개발하여 'VIVA(Virtual Imaging & Virtual Advertising)'라 이름지었다. 이 시스템은 렌즈 데이터에 근거하여 카메라 캘리브레이션을 수행하며, 주밍(zooming)시 발생하는 카메라의 시점(view point) 변화를 반영하여 원거리 촬영이 이루어지는 스포츠 중계뿐만 아니라 보다 정확성이 요구되는 스튜디오 내의 근거리 프로그램 제작에도 사용이 가능하다. 합성되는 그래픽은 실세계와 같은 완전한 3차원 좌표 공간에 놓이게 되며, 월드 좌표계와 카메라 좌표계를 이용하여 사전 제작된 오브젝트들을 원하는 곳에 위치시킬 수 있다. 실사와 그래픽의 효과적인 합성을 위하여 오버레이(overlay) 모드는 물론 알파키(alphakey)와 크로마키(chromakey)를 조합한 모드를 사용하였다. VIVA는 2002년 부산 아시안 게임에서 수영과 양궁 중계에 활용하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.408-415
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• 2016

The vehicle attitude and sideslip is critical information to control the vehicle to prevent from unintended motion. Many of estimation strategy use bicycle model or IMU integration, but both of them have limits on application. The main purpose of this paper is development of vehicle orientation estimator which is robust to various vehicle state and road shape. The suggested estimator use 3-axis magnetometer, yaw rate sensor and lateral acceleration sensor to estimate three Euler angles of vehicle. The estimator is composed of two individual observers: First, comparing the known magnetic field and gravity with measured value, the TRIAD algorithm calculates optimal rotational matrix when vehicle is in static or quasi-static condition. Next, merging 3-axis magnetometer with inertial sensors, the extended Kalman filter is used to estimate vehicle orientation under dynamic condition. A validation through simulation tools, Carsim and Simulink, is performed and the results show the feasibility of the suggested estimation method.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.238-245
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• 2010

Stroke patients can't use their hands because of the paralysis of their fingers. Their fingers are recovered by rehabilitating training, and the rehabilitating extent can be judged by grasping a spherical object. At present, the object used in hospital is only a spherical object, and can't measure the force of fingers. Therefore, doctors judge the rehabilitating extent by touching and watching at their fingers. So, the spherical object measuring system which can measure the force of their fingers should be developed. In this paper, the finger-force measuring system with a three-axis force sensor which can measure the spherical-object grasping force is developed. The three-axis force sensor is designed and fabricated, and the force measuring device is designed and manufactured using DSP(digital signal processing). Also, the grasping force test of men is performed using the developed finger-force measuring system, it was confirmed that the average force of men was about 120 N.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1288-1295
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• 2002

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor has high stiffness and low cost. The radius of the column was designed analytically and compared with finite element analysis. The interference errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine. The calibration results showed that the 6-component forces and moments sensor had interference error less than 7.3 % between $F_x$ and $M_x$ components, and 5.0 % in case of other components.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.179-185
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• 2014

In this paper, a quadruped walking pet robot for human-robot interaction, a robot-controller using a smart phone application program, and a home smart control system using sensor informations providing from the robot are described. The robot has 20 degree of freedom and consists of various sensors such as Kinect sensor, infrared sensor, 3 axis motion sensor, temperature/humidity sensor, gas sensor and graphic LCD module. We propose algorithms for the robot entertainment: walking algorithm of the robot, motion and voice recognition algorithm using Kinect sensor. emotional expression algorithm, smart phone application algorithm for a remote control of the robot, and home smart control algorithm for controlling home appliances. The experiments of this paper show that the proposed algorithms applied to the pet robot, smart phone, and computer are well operated.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.150-156
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• 2007

In this paper, we focus on the fault detection and isolation(FDI) method for inertial navigation system with three two-degree of freedom dynamically tuned gyros(DTG) on orthogonal sensor configuration. we propose the FDI method which can detect the fault of each DTGs rather than the fault of each sensing axis. The proposed FDI method is separated into two FDI modules according to the fault magnitude in order to improve the reliability of fault detection information. For large fault detection, only instantaneous DTG measurement is used to detect a fault DTG within a short time. For small fault detection, the integrated value of DTG measurements are used to detect a fault DTG. It takes a more time to detect a fault but it serves more reliable fault detection information. Using the proposed FDI method with consideration of DTG fault characteristic, we could find out a fault DTG successfully.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.5
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• pp.21-27
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• 2008

Despite recent studies on development of pulse diagnosis systems and needs for commercializing them, the reproducibility is one of the most controversial issues as ever. Because the pulse pressure value, which is one of the important parameters to evaluate reproducibility, is very vulnerable to moving artifacts, the reproducibility can not be obtained easily. In this paper, we suggested a moving artefacts detection system for a pulse diagnosis system so that a pulse diagnosis system can be robust to theses kinds of artefacts by excluding the contaminated parts from the pulse wave signal to be analyzed. This moving artifacts detection system was designed to consist of a three-axis accelerometer, an electromyography amplifier and a two-axis tilt sensor. To assess the suitability of the system, we examined the characteristics of each sensor's output signals with regard to the three specific motions such as extension, flexion and rotation. And, we also examined the each sensor's response to the high-frequency and low-frequency moving artifacts while the pulse wave signal was acquired from a pressure sensor for the pulse diagnosis. From these results, we could find that the response to subject's motions would be reflected in electromyography signal first, in accelerometer signals and in tilt sensor sequently. And, the facts that a stable pulse wave can be acquired in two seconds after high frequency or low frequency motions ended, were also found. Consequently, based on these findings, we set up some rules on the moving artifacts detection and designed an algorithm which is fit for our moving artifacts detection system.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.238-247
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• 2014

The milking robot system is very important to detect correctly the teats position in the moving condition of cow. Also, the robot manipulator must control tracking the teat cup to the detected teat position. The presented milking robot is designed using the one point laser sensor for teat position detection. The teats of cow are detected by the laser scanning unit and the manipulator has the function of 3 axes moving control unit. The presented teat detection method and the electrical driving manipulator have the advantages of a simple, low cost and very quiet. The designed manipulator is realized by the totally electrical motor and servo poison control algorithm with velocity PID compensation. The presented robot is realized using the teat detection unit, 4 teat cups, 3 axes robot arm, 6 servo motors and automatic milking control line. The designed robot is experimented in the cow farm and is satisfied with the designed performance specification for milking robot manipulator.