Earticle

This study proposes a mother-slave robot tracking system that identifies the target, predicts its location, and tracks it based on a single image. The proposed system utilizes a Convolutional Neural Network (CNN) for object detection, to identify the target robot. The distance and angle between the robots are then calculated through linear regression analysis, which offers a more efficient and cost-effective solution than traditional methods. The performance of the system was evaluated, resulting in an accuracy of 99.59% for object detection, and an average distance error of 2.04% for the estimated location.

다채널 핵의학 영상 검출 시스템에서 채널수를 줄이기 위해 사용되는 resistive network와 전하증폭기를 분석하였다. 시스템에서 사용되 는 다채널 광전자증배관은 수 ㎲ 이하의 duration을 갖는 펄스 형태의 전류 신호를 출력한다. 다채널 광전자증배관을 사용한 검출 시스템은 높은 해상도를 갖지만, 신호를 처리할 수 있는 많은 회로가 필요하다는 단점이 있다. 이는 resistive network를 사용하여 일정한 비율에 따라 4개의 출력으로 줄여 해결 할 수 있다. 4개로 분배된 전류신호는 전하증폭기에 의해 적분되어 전압신호로 변환되고, 출력신호의 최댓값을 통하여 검출위치를 추정할 수 있게 된다. 본 논문에서는 resistive network와 전하증폭기를 이용한 검출위치 추정방법을 소개하고, 시뮬레이션을 사용하여 분석하였다.

본 논문은 PV 시스템에 발생하는 단선 고장의 위치를 검출하는 방법을 제시한다. PV 시스템은 외부에 설치되기 때문에 설치 조건 및 기후환경에 따라 효율이 크게 좌우된다. PV 모듈의 전압 및 용량이 낮기 때문에 원하는 출력을 얻기 위해 다수의 PV 모듈을 연결하여 사용하며 PV 모듈을 연결하는 케이블, 커넥터의 부식 및 연결 불량 등은 PV 모듈의 단선 고장을 유발하여 PV 시스템의 전력손실을 매우 크게 발생시킨다. 또한 케이블, Junction Box 및 단자대 등에서 발생하는 단선 고장은 육안으로 확인되지 않은 경우가 많아, 고장 발생에서 제거 까지 상당한 시간이 소요된다. 본 논문에서는 PV 모듈에 고주파가 주입될 때 나타내는 기생 커패시터를 이용하여 단선 고장의 위치를 검출하는 방법을 제시한다. 기생 커패시터는 유효 표면적에 비례하며, 연결된 PV 모듈의 수 에 따라 비례적으로 증가하는 특징을 가진다. 본 논문은 단선의 위치에 따라 기생 커패시터를 측정하고 그 값을 비교하여 단선 위치를 검출하며, 시뮬레이션을 통한 결과 분석을 통해 타당성을 입증한다.

This paper proposes a method for localization of a disconnection fault in a PV system. PV systems are installed outside, their efficiency greatly depends on the installation conditions and climatic environment. Because the voltage and capacity of PV modules are small, multiple PV modules are connected and used to obtain the demanded output. Corrosion and poor connection of cables and connectors connecting PV modules can cause disconnection failure of PV modules, causes a very large loss. In addition, disconnection failures occurring in cables, junction boxes, and terminal blocks are difficult to observe with the naked eye, so it takes a considerable amount of time from occurrence to removal. This paper presents a method for detecting the location of a disconnection fault using a parasitic capacitor that is indicated when a high frequency is injected into a PV module. The parasitic capacitor is proportional to the effective surface area and has a characteristic that increases proportionally according to the number of connected PV modules. This paper measures the parasitic capacitor according to the position of the disconnection, compares the value to detect the disconnection position, and proves its validity through the analysis of the result through simulation.

본 연구에서는 골프의 타수에서, 약 40 %를 차지하는 퍼팅의 연습에 필요한 지능형 퍼팅 연습기를 개발하였다. 개발된 연습기에서는 퍼팅된 골프공의 거리 및 방향을 표시할 뿐 아니라, 반복 타격된 퍼팅의 결과를 분포도 형상으로 그 결과를 표시하여, 사용자에게 직관적으로 통계적 결과를 알 수 있도록 제시하여 준다. 이 연습기에서는 사용자가 골프볼을 정확한 초기 위치에 두고 연습 타격을 하는 불편을 없애기 위하여,볼의 초기 위치를 자동으로 인식하는 센서 시스템 및 알고리즘을 개발하여 적용하였다.

This study is on the development of digital putting pratice system based on artificial intelligence algorithm. In this system, estimated distance and direction of the golf ball are displayed after the ball is hit. Moreover the results are displayed as a distribution chart, which can show the putting performance of the user and be analyzed intuitively by the user. In this system, automatic position detection method, including sensor system and algorithm, is developed and implemented, which is used for the detection of the primary position of the golf ball before putting.

Reliability is an essential performance in GPS navigation system. Therefore, satellite fault detection is considered as one of the most important functions in GPS receivers. For the declining problem of the ability of fault detection for the traditional GPS satellite fault detection algorithm under the condition of small fault, a new GPS satellite fault detection algorithm based on wavelet analysis is proposed. The raw pseudorange measurements and the positioning data information are transformed by wavelet analysis and the data jumping point can be detected and identified through the different wavelet scales, and the satellite fault could be detected. Two kinds of GPS satellite fault detection methods are given in detail, and the advantages and disadvantages of them are compared. Validated by the real collected raw data from the GPS receiver, the results show that the wavelet analysis method can detect smaller mutations in a sequence of parameters, and the feasibility and effectiveness of applying the wavelet analysis algorithm in satellite fault detection for GPS receiver are verified.

Various techniques that employ Global Positioning System(GPS) signals such as A-GPS and GPS transmitters, have been introduced with the hope to provide a solution for indoor positioning detection. Indoor positioning system (IPS) is a term that is used for network devices used to wirelessly locate objects or people inside building. The study is based on the issue in order to determine the position of an object in indoor environment or inside a building. The problems arise when the position of an object inside a building cannot be determined using GPS. We proposed the implementation of trilateration technique to determine the position of users in indoor areas based on Wi-Fi signal strengths from access points (AP) within the indoor vicinity. In this paper, percentage of signal strengths obtained from Wi-Fi analyzer in a smartphone were converted into distance between users and each AP. A user’s indoor position could then be determined using a formula proposed based on trilateration technique.

We propose a position detection mechanism enabling location-aware Pin&Play. Though the positions of inserted pins are important for most applications, it could not be detected in previous systems. The proposed method detects the positions of pins by processing images taken with a camera placed in front of the board. The proposed method has an error estimation mechanism to avoid the accumulation of position error. We also clarify the effectiveness of our proposed method through performance evaluations.

One of key goals of disaster response and relief robots is to acquire knowledge about the situation that would be either dangerous or inaccessible to human operator. However, the robot is difficult to acquire tele-operations from the operator. A disconnected communication link and no-visual control situation are frequently happened in disaster areas. Moreover, disaster scenarios are typically spatially distributed, so we may need an intelligent robot that has functions such as autonomy, cooperation, and collective behaviors. Thus, we propose the bio-inspired modular robot named as ARTHROBOT so as to support emergency responders. ARTHROBOT can assemble or disassemble process based on the proposed mobile algorithms.

브러시리스 DC 전동기(BLDC)는 스위치의 on/off 각이 최적의 고정자와 회전자의 정렬상태에 의해 결정되는 반면에, 스위치드 릴럭턴스 전동기 (SRM)은 스위치의 on/off 각이 많은 파라미터의 복잡한 함수로 나타나고 따라서 최적의 운전을 하기 위해서는 스위칭 각이 가변적으로 된다. 따라서 스위치드 릴럭턴스 전동기 (SRM)을 최적으로 운전 하기 위해서 고해상도의 위치 센서와 복잡한 부가 회로 등을 이용하여 회전자 위치를 검출할 수 있다. 본 논문에서는 스위치드 릴럭턴스 전동기 (SRM)를 구동할 수 있는 여러 가지 방법 중 엔코더, 홀센서, 옵토-인터럽터 (opto interrupter) 등 다양한 센서들을 활용하여 회전자 위치 검출 및 관련 위치 검출 회로적용, 검출된 회전자의 초기위치 확보에 관한 연구를 하였다.

In brushless DC motors (BLDC), the on/off angle of the switch is determined by the optimal alignment of the stator and rotor, while switched reluctance motors (SRM) are complex parameters with many on/off angles of the switch. It appears as a function and therefore the switching angle is variable for optimal operation. Therefore, in order to operate the switched reluctance motor (SRM) optimally, the rotor position can be detected using a high resolution position sensor and a complicated additional circuit. In this paper, rotor position detection and related position detection circuits are applied and detected by using various sensors such as encoder, hall sensor and opto interrupter among several methods to drive switched reluctance motor (SRM). Also a study on securing the initial position of the rotor was conducted.

BLDC 전동기는, 영구자석의 고성능화를 비롯한 소재 기술 향상, 고집적∙고기능화를 갖는 구동 IC 기술의 진보, 고점적율화 등의 조립 기술 개선 등으로 인하여 성능이 점점 좋아지고 있다. 이러한 구형파 구동 BLDC 전동기의 장점이 있으면서 보다 사용자의 요구에 대응하기 위해 구형파 구동 BLDC 영구자석 전동기 설계 및 개발, 위치검출방식 회로와 드라이버 개발에 관심이 증가하고 있다. 그러나 스위칭 손실에 의한 효율 저하 및 진동, 소음 등으로 인하여 가격적∙기능 적인 장점에도 불구하고 그 응용에 있어서는 다소 제한적인 실정이다. 따라서 본 논문에서는 정현파가 발생하는 Hall Effect Sensor를 사용하여 BLDC 전동기 회전자의 자속에 비례하여 정현파 신호를 만드는 위치검출 회로를 연구하여 전동기의 효율 증대, 리플 저감, 속도 및 토크 특성이 우수한 정현파 전류 구동을 구현하고자 한다.

BLDC motors are getting better performance due to the improvement of material technology including high performance of permanent magnets, advancement of driving IC technology with high integration and high functionality, and improvement of assembly technology such as high point ratio. While having the advantage of such a square wave driven BLDC motor, interest in the design and development of a square wave driven BLDC permanent magnet motor and development of a position detection circuit and driver is increasing in order to more meet the needs of users. However, in spite of the cost and functional advantages due to reduced efficiency, switching loss and vibration, noise, etc., the application is somewhat limited. Therefore, in this paper, we study a position detection circuit that generates a sinusoidal signal in proportion to the magnetic flux of a BLDC motor rotor using a Hall Effect Sensor that generates a sinusoidal wave to increase the efficiency of the motor, reduce ripple, and drive a sinusoidal current with excellent speed and torque characteristics.

폐기물 환경 시설에서 폐기물 운반 차량의 폐기물 매립장 내 이동 경로와 폐기물 투척 위치를 추적하여 기 록함으로써 향 후 폐기물 매립지 재사용을 위한 이력관리를 효율적으로 진행할 수 있다. 이들 폐기물 매립 위치 정보 들을 3D 로 매핑하고 위치를 추출하여 최종 매립위치와 매립물 기록을 추출하기 위한 새로운 연구 방법이 다양한 실 험조건하에서 구현되었다. 본 연구에서는 쓰레기 매립장 내에서의 차량의 이동경로와 매립시점을 판단할 수 있는 방 법을 제시한다. 현재의 영상과 배경영상의 차를 구하여 차량의 이동경로를 추적하고 이동경로의 형태로부터 정차 여 부를 판단할 수 있으며, 정차시의 영상과 배출구의 개방영상과의 비교를 통해 폐기물의 매립시점을 검출할 수 있도록 한다. 감시 카메라의 설치정보를 이용하며 매립지 평면상의 좌표와 화면좌표를 변환할 수 있는 방법을 제시한다.

In waste repository environment, we can process the waste history efficiently for reuse by recording the history trajectory of the vehicle which loaded waste and the dumping position of the waste vehicle. By mapping the unloaded waste to 3D and by extracting the dumping point, a new method was implemented so as to record the final dumping position and the waste content under various experiments. In this paper, we developed the algorithm which tracking the vehicle and deciding the moment of dumping in landfills. We first trace the position of vehicle using the difference image between current image and background image and then we decide the stop point from the shape of vehicle route and detect the dumping point by comparing the dumping image with the image that vehicle is stopping. From the camera parameters, The transform method between screen coordinate and real coordinate of landfills is proposed.

스마트폰을 이용한 실내에서의 위치 기술이 다양하게 연구되고 있다. 그 중 스마트폰에 내장된 가속도 센서와 자이로 센서를 이용한 위치 추적 기술은 WiFi fingerprint 기술 등과 함께 연동되어 많이 사용되고 있다. 센서를 이용한 위치 추적 기술은 오래 전부터 사용되어 왔으나, 스마트폰의 경우 센서의 성능이 좋지 않고 사용자가 스마트폰을 일정한 자세로 들고 이동하는 등 사용 환경이 특이하다. 따라서 스마트폰 환경에서 위치 추적의 정확도를 높이기 위해서는 고유의 환경에서 적절 한 알고리즘을 연구 개발해야 한다. 본 논문에서는 사용자의 이동 걸음 수 검출 알고리즘인 주파수 분석 방식, 최대 최소 가속도의 합 방식 및 적응형 임계값 방식에 대한 다양한 실험 환경에서의 성능을 분석하고, 가장 정확한 방식을 선정한다.

Various techniques for indoor positioning using a smart phone have been studied. Among them, the positioning technology using the acceleration sensor and the gyro sensor built in the smartphone is widely used in conjunction with the WiFi fingerprint technology. The location tracking technology using sensors has been used for a long time, but the performance environment of the smartphone is poor and the user is moving with the smartphone in a certain posture. Therefore, in order to improve the accuracy of location tracking in a smartphone environment, it is necessary to study and develop appropriate algorithms in a mobile environment. In this paper, we analyze the performances of frequency analysis method, maximum sum of minimum acceleration method and adaptive threshold method, which are the user's moving step count detection algorithms, and determine the most accurate method.

In this paper, we present a method to detect the position of a 3D object in scattering media by using the axially distributed sensing (ADS) method. Due to the scattering noise of the elemental images recorded by the ADS method, we apply a statistical image processing algorithm where the scattering elemental images are converted into scatter-reduced ones. With the scatter-reduced elemental images, we reconstruct the 3D images using the digital reconstruction algorithm based on ray back-projection. The reconstructed images are used for the position detection of a 3D object in the scattering medium. We perform the preliminary experiments and present experimental results.

Six-step commutation control widely used in brushless DC (BLDC) motor can be applied to consequent pole permanent magnet (CPPM) belt starter generator (BSG) with trapezoidal back electromotive force (EMF) in the starter state. However, rotor position detection with three Hall sensors in BLDC motor can hardly be employed in CPPM BSG due to asymmetric flux distribution in each pole side of CPPM BSG. This paper presents a low-cost rotor position detection method for CPPM BSG in which six Hall sensors are proposed to be used based on the analysis of flux distribution by 3D FEA. In the method, the six Hall sensors are divided into three groups and two signals in each group are combined through performing logic operations. In addition, offset angle between back EMF and the related Hall signal can be compensated by moving the Hall sensors. Experiments of a 2 kW CPPM BSG prototype have also been performed to verify the proposed method.

TOA(Time of Arrival) 및 TDOA(Time Difference of Arrival)경우 무선국의 시간동기화를 위해서 고도의 기술을 요구하고 있으며, 시간동기오차에 따른 위치검지의 정밀도가 낮아지는 문제가 있어 이를 극복하기 위하여 위상차(PDOA)를 이용한 새로운 열차검지기법의 제안에 따른 구현을 위하여 H/W의 설계에 대하여 기술하고자 한다 본 시스템은 전과의 전달 속도($\lambda$)를 응용하여 기준 주파수인 1.5MHz를 송신 시스템과 수신 시스템의 기준 주파수와 비교하여 그 위상의 차이를 비교하여 지연된 시간을 구한 후 이를 거리로 환산하는 시스템으로서 H/W와 S/W로 구분하여 구현 $\cdot$ 설계되는데 본 논문에서는 H/W설계에 대하여 기숙하였다.

Occupant classification and position detection have been significant research areas in intelligent safety systems in the automotive field. The detection and classification of seat occupancy open up new ways to control the safety system. This paper deals with a novel algorithm development, hardware implementation and testing of a prototype intelligent safety system for occupant classification and position detection for in-vehicle environment. Borland C++ program is used to develop the novel algorithm interface between the sensor and data acquisition system. MEMS strain gauge hermatic pressure sensor containing micromachined integrated circuits is installed inside the passenger seat. The analog output of the sensor is connected with a connector to a PCI-9111 DG data acquisition card for occupancy detection, classification and position detection. The algorithm greatly improves the detection of whether an occupant is present or absent, and the classification of either adult, child or non-human object is determined from weights using the sensor. A simple computation algorithm provides the determination of the occupant's appropriate position using centroidal calculation. A real time operation is achieved with the system. The experimental results demonstrate that the performance of the implemented prototype is robust for occupant classification and position detection. This research may be applied in intelligent airbag design for efficient deployment.

TOA(Time of Arrival) 및 TDOA(Time Difference of Arrival)경우 무선국의 시간동기화를 위해서 고도의 기술을 요구하고 있으며, 시간동기오차에 따른 위치검지의 정밀도가 낮아지는 문제가 있어 이를 극복하기 위하여 위상차를 이용한 새로운 열차검지기법의 제안에 따른 구현을 위하여 무선장치 설계에 대하여 기술하고자 한다. 본 시스템은 전파의 전달 속도($\lambda$)를 응용하여 기준 주파수인 1.5MHz를 송신 시스템과 수신 시스템의 기준 주파수와 비교하여 그 위상의 차이를 비교하여 지연된 시간을 구한 후 이를 거리로 환산하는 시스템으로서 무선장치와 S/W로 구분하여 구현 설계하였다.

A simple fault correction method for rotor position detection of a brushless DC(BLDC) motor with trapezoidal back EMF(electromotive force) using a Hall effect latch unit is presented. The reason why the Hall effect latch unit does not operate properly during the startup of a BLDC motor is thoroughly explained. To solve this problem, a simple code change method and its hardware implementation issues are proposed and discussed.

The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensor-based methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.