Earticle

무선 위치 추적 시스템은 모바일, 로봇 추적 시스템 및 인터넷 위치 기반 서비스(LBS) 애플리케이션과 같은 응용분야에서 사용할 수 있다. GPS 시스템은 가장 잘 알려진 위치 추적 시스템이지만 실내에서의 사용이 용이하지 않 다. 실내 위치 추적 시스템에 대한 비용 효율적인 측면에서 무선 주파수 식별(RFID) 위치 추적 방법을 연구하였다. RFID 시스템 대부분은 소모성 배터리를 사용하는 능동형 RFID 태그를 사용지만, 본 논문에서는 패시브 RFID 태그를 사용하는 저렴한 실내 위치 추적 시스템을 개발하였다. 정밀한 추적 알고리즘을 사용하기 위하여 패턴인식에 의한 위치 추적 방법과 회귀곡선을 생성하여 위치를 추적하는 시스템을 연구하였다. 시스템은 잡음으로 인한 오류 수준을 검증하 여 테스트하였다. 회귀식에 의해 생성된 3차원 곡선은 미분방정식에 의해서 확률적으로 설명력이 높은 좌표를 추정하였 다. 이 제안된 시스템은 모바일 로봇 시스템, AGV 및 휴대전화 LBS에도 적용될 수 있다.

Location positioning systems are available in applications such as mobile, robotic tracking systems and Wireless location-based service (LBS) applications. The GPS system is the most well-known location tracking system, but it is not easy to use indoors. The method of radio frequency identification (RFID) location tracking was studied in terms of cost-effectiveness for indoor location tracking systems. Most RFID systems use active RFID tags using expendable batteries, but in this paper, an inexpensive indoor location tracking system using passive RFID tags has been developed. A pattern matching method and a system for tracing location by generating regression curves were studied to use precision tracking algorithms. The system was tested by verifying the level of error caused by noise. The three-dimensional curves are produced by the regression equation estimated the statistically meaningful coordinates by the differential equation. The proposed system could also be applied to mobile robot systems, AGVs and mobile phone LBSs.

Position tracking of a user or an object has caught many researchers and entrepreneurs’ attention. It has a significant market opportunity as well as applications in daily life such as Earth sciences, intelligent transportation systems, machine control, mapping, surveying, surveillance, tracking, and vehicle testing. The accuracy of different positioning methods depends upon the accuracy of underlying technology and environmental conditions. In this paper, a hybrid adaptive method is developed to enhance the accuracy of positioning. Based on the accuracy and the environments, a coefficient (weight) vector is assigned to the coordinates obtained from INS, GPS, Cellular Network, and Wi-Fi methods. Subsequently, the weighted average method is used to integrate the coordinates to compute the location. The proposed method is tested in an experimental study with different distance settings. The accuracy and robustness of suggested method are validated with GPS and INS hybrids.

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.

본 논문은 가시광 통신 시스템에서 시스템 성능 향상 위해 광 빔포밍 전송기법을 적용할 때 광 신호 방사 범위 내에 단일 또는 다수 의 접속 유저 단말(Rx)을 추적하는 방법에 관한 것 이다. 광 빔포밍 전송기법은 RF에서 빔 형성 전송 방법과 매우 유사하여 가시광 통신 시스템의 통신 신호인 가시 광 신호를 유저 단말에게 전송할 때 빔 형성 벡터를 곱하여 특정 유저에게 질 좋은 가시 광 채널을 형성해 주는 기법이다. 이러한 광 빔포밍 전송을 적용하기 위해서는 먼저 가시 광 셀 내에 이동성을 가진 단말을 포함해 접속해 있는 유저 단말의 위치 추적이 필요하다. 따라서 본 논문에서 하나의 가시 광 셀 내에 접속해 있는 유저 단말 추적 방법을 광 AP(Access Point)와 UE(User Equipment) 1:1 샘플을 취하여 기술하였고 이러한 UE 추적 방법을 통해 광 빔포밍 전송 기법을 적용 했을 때 얻을 수 있는 5~6dB 정도의 SNR 성능 이득을 모의실험을 통하여 확인하였다.

In this paper, we propose a novel UE(User Equipment) position tracking algorithm of visible light signals, and analyze BER performance when optical beamforming scheme is applied in VLC(Visible Light Communications) system. The optical beamforming scheme as an interference mitigation method provides good optical channel conditions between UE(Rx) and LED light(Tx), and lead to better BER performance because UE is able to get a better RSSI(Received Signal strength indication) value. For the system BER, the proposed UE position tracking method for optical beamforming transmission demonstrates the performance enhancement compared to a system not applied the optical beamforming transmission scheme, and up to about 5~6dB SNR performance gain is achieved. The results of the paper can be applied to design of various VLC and LBS applications for ubiquitous home network systems.

User motion recognition through image recognition has attracted considerable attention with the development of the Kinect senor by Microsoft. The Kinect exhibits excellent motion recognition performance at a small expense via a motion tracking method utilizing an RGB-D camera. Further, the Kinect offers the advantage that applications can be easily written for it using the Kinect SDK. However, the Kinect also suffers from the disadvantage that it is unable to recognize an image “shielded” by an object because of the application of the vision recognition method by the camera. Consequently, it is difficult to obtain accurate data concerning user movement. Studies on observing an object from various directions with multiple Kinects are being conducted to compensate for this problem, and it is possible to acquire the movement data for only one user in these studies. This study implements the human body trace system for multiple users. We suggest a method to compensate for the location of the user and motion data that cannot be recognized by one Kinect using data acquired by multiple Kinects.

User motion recognition through image recognition has attracted considerable attention with the development of the Kinect senor by Microsoft. The Kinect exhibits excellent motion recognition performance at a small expense via a motion tracking method utilizing an RGB-D camera. Further, the Kinect offers the advantage that applications can be easily written for it using the Kinect SDK. However, the Kinect also suffers from the disadvantage that it is unable to recognize an image “shielded” by an object because of the application of the vision recognition method by the camera. Consequently, it is difficult to obtain accurate data concerning user movement. Studies on observing an object from various directions with multiple Kinects are being conducted to compensate for this problem, and it is possible to acquire the movement data for only one user in these studies. This study implements the human body trace system for multiple users. We suggest a method to compensate for the location of the user and motion data that cannot be recognized by one Kinect using data acquired by multiple Kinects.

We are designed the delivery constitution technique that is to be measure the safe RFID statusof thewireless delivery system level (WDSL) on the delivery system tracking system. The delivery system level condition by the delivery system tracking system is organized with the RFID system. As to inspection a wireless network of the wireless network, we are found of the delivery value with wireless network by the upper take form. The concept of delivery system level is organized the reference of wireless level for delivery signal by the delivery RFID tracking system. Further, symbolizing a safe deliveryof the WDSL of the medium-minimum interval of the RFID tracking system, and the delivery wireless network RFID that was the delivery value of the far delivery of the DSTS-FA-φMED-MIN with 5.80±1.20 units, that was the delivery value of the convenient delivery of the DSTS-CO-φMED-MIN with 4.06±(-0.04) units, that was the delivery value of the flank delivery of the DSTS-φMED-MIN with 0.91±0.07 units, that was the delivery value of the vicinage delivery of the DSTS-VI-φMED-MIN with 0.18±(-0.03) units. The RFID will be to look into at the safe of the RFID tracking systemwith wireless network bythe delivery system level on the WDSL that is supply the wireless tracking system by the delivery system level system. We will be possible make to curb of a tracking system that to put the wireless signal and to use of the delivery data of RFID level by the delivery system.

RFID는 정보를 초소형칩에 내장시켜 이를 무선주파수로 추적할 수 있도록 한 기술이다. 현재 RFID는 물류, 미아방지시스템, 버스카드 등 다양한 분야에서 널리 사용되고 있다. 본 논문에서는 이러한 RFID 기술을 기반으로 GPS와 접목하여 소지품 위치추적 시스템을 제안 설계한다. 제안된 시스템의 주요특징은 다음과 같다. 첫째, 중요한 소지품을 분실할 경우 실시간으로 위치를 추적한다. 둘째, 분실물의 위치 정보를 사용자에게 제공함으로써 분실물을 습득할 수 있다. 제안 설계된 시스템의 성능평가는 AVD(Android Virture Device)를 이용하여 수행하였다.

RFID is new recognition technology which can trace IC chip(built in information) with wireless frequency. The present RFID is used in parcel service, missing child potection system, bus card, and extensive areas. This paper proposes and designs a belongings position tracking system using RFID with GPS. The main features of the proposed system are as follows. First, the system can in real time track the lost belongings. Second, the system can provide lost belonging location information to the users. The performance evaluation of the proposed system is performed by using AVD(Android Virture Device).

전쟁과 군사훈련 상황에서는 상급부대들은 하급부대들에 빠르고 정확하게 작전명령을 내려야 한다. 따라서 전술통제센터에서는 하급부대의 현재 위치를 정확하게 파악하는 것이 중요하다. 본 논문에서는 군에서의 스파이더 시스템에는 구축되어 있지 않은 하급부대의 정확한 위치를 파악하기 위해 GPS 데이터를 사용한 자동 위치추적 시스템을 구현한다. 또한 육각형 셀을 이용하여 명령을 빠르고 정확하게 전달하기 위한 명령 시스템도 개발한다. 제안된 시스템은 HSDPA 모뎀을 사용하여 하급부대의 좌표들을 상급부대에 전송하고 상황판에 그림을 그린다. 이 시스템은 디지털 지도상에 한 개 이상의 하급부대의 위치를 그릴 수 있다.

In the war and military drill situation, upper-grade units must quickly and exactly send commands to lower-grade units. So it is very important to control current location of lower-grade units at the command center. In this paper, we implement an automatic location tracking system to check the location of lower-grade units quickly and exactly by using data of GPS in battalion that not is not built in the Spider-System. We also develop a command system using hexagon cells to order command quickly and exactly. The proposed system sends coordinates of lower-grade units to upper-grade unit using HSDPA modem in real time and draws the coordinates on the map. This system can draw more than one coordinates of lower-grade units on the digital map.

실내 위치 기반서비스는 일상에서 주로 움직이는 사용자를 대상으로, 측정하고 분석하는 지능형 사물인터넷기 술 기반으로 발전되어왔다. 다양한 실내 위치 측위 기술들은 별도의 하드웨어를 필요로 하고 통신 프로토콜이 복잡해 지는 단점이 있다. 본 논문에서 사용되는 무선 신호의 수신강도를 이용하는 RSSI 기술은 송신 신호의 물리적인 특성 상 거리에 따라 신호 세기의 감소가 일어나는 점에 착안하여, 송신 신호의 강도와 수신 신호의 세기를 측정하여 송신 기와 수신기 간의 거리를 측정하는 방법으로 별도의 비용이 들지 않고 측정 구현이 간단한 장점을 이용하였다. 측정되 는 RSSI 값의 오차를 줄이기 위해 Feedback 필터링에 대한 계산 값을 산출 적용시켰다. 평균 필터링을 통한 RSSI 값과 Feedback 필터링의 계수 값을 0.5로 설정하여 측정한 RSSI 값이 일반적인 측정에 비해 최대 –61dBm에서 최소 –52.5dBm 으로 약 –2dBm에서 –6dBm 정도 감소하는 것을 확인하였다.

Indoor location-based services have been developed based on the Internet of Things technologies which measure and analyze users who are moving in their daily lives. These various indoor positioning technologies require separate hardware and have several disadvantages, such as a communication protocol which becomes complicated. Based on the fact that a reduction in signal strength occurs according to the distance due to the physical characteristics of the transmitted signal, RSSI technology that uses the received signal strength of the wireless signal used in this paper measures the strength of the transmitted signal and the intensity of the attenuated received signal and then calculates the distance between a transmitter and a receiver, which requires no separate costs and makes to implement simple measurements. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance.It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from –61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about –2 dBm to -6 dBm as compared to general measurements.

스마트폰을 이용한 실내 위치 추적 기술에 관한 연구가 활발하게 진행되고 있다. 특히 스마트폰의 이동 경로를 지도 에 표시하기 위해서는 대부분의 스마트폰에 내장되어 있는 지자기 센서를 이용하여 방위각을 추정해야 하는데, 주변의 쇠구 조물에 의한 자기장의 왜곡과 스마트폰의 기울어짐 때문에 방위각 추정 오차가 발생한다. 본 논문에서는 정지 상태에서의 지자기 센서의 보정 방법과 스마트폰의 기울어짐에 대한 보정 방법을 제시한다. 또한 스마트폰에서 자북과 도북의 차이에 의한 방위각 오차를 보정하는 방법을 제안한다.

Research on indoor location tracking technology using smart phone is actively being carried out. Especially, in order to display the movement path of the smartphone on the map, the azimuth angle should be estimated by using the geomagnetic sensor built in most smart phones. Due to the distortion of the magnetic field due to the surrounding steel structure and the inclination of the smartphone, the estimation error of azimuthal angle may be occurred. In this paper, we propose a correction method of the geomagnetic sensor at the stationary state and a correction method for the inclination of the smartphone. We also propose a method to correct the azimuth error due to the difference between the magnetic north and the grid north.

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.

이 논문에서는 압전작동기를 이용하여 유연 보 구조물의 위치추적제어를 실험적으로 고찰하였다. 작동기의 히스테리시스 특성을 보상하기 위한 앞먹임 보상기와 PID 되먹임 제어기를 함께 구성하여 정밀한 위치 추적제어를 수행할 수 있도록 하였다. 히스테리시스 보상기는 압전작동기의 예측 변위를 바탕으로 한 프라이작 모델을 사용하여 구성하였다. 히스테리시스 보상기의 유무에 따른 PID 되먹임 제어의 성능을 조화가진과 랜덤 가진 실험을 통하여 평가하였으며, 보상기와 되먹임 제어기를 함께 사용하였을 때, 우수한 위치추적제어 성능을 가지는 것을 확인하였다.

This paper presents a position tracking control of a flexible beam using the piezoelectric actuator. This is achieved by implementing both feedforward hysteretic compensator of the actuator and PID feedback controller. The Preisach model is adopted to develop the feedforward hysteretic compensator. In the design of the compensator, estimated displacement of the piezoceramic actuator is used based on the limiting triangle database that results from collecting data of the main reversal curve and the first order ascending curves. Experimental implementation is conducted for position tracking control and performance comparison is made between a PID feedback controller without considering the effect of hysteresis, and a PID feedback controller integrated with the feedforward hysteretic compensator.

This paper presents a position tracking control of a flexible beam using the piezoelectric actuator. This is achieved by implementing both feedforward hysteretic compensator of the actuator and PID feedback controller. The Preisach model is adopted to develop the feedforward hysteretic compensator. In the design of the compensator, estimated displacement of the piezoceramic actuator is used on the basis of the limiting triangle database that results from collecting data of the main reversal curve and the first order ascending curves. Experimental implementation is conducted for position tracking control and performance comparison is made between a PID feedback controller without considering the effect of hysteresis, and a PID feedback controller integrated with the feedforward hysteretic compensator.

The Internet's low cost and ubiquity present an attractive option for real-time distributed control of processes on the factory floor. When integrated with the Internet, the LonWorks open control network can give ubiquitous accessibility with the distributed control nature of information on the factory floor. One of the most important points in real-time distributed control of processes is timely response. There are many processes on the factory floor that require timely response. However, the uncertain time delay inherent in the network makes it difficult to guarantee timely response in many cases. Especially, the transmission characteristics of the LonWorks/IP network show a highly stochastic nature. Therefore, the time delay problem has to be resolved to achieve high performance and quality of the real-time distributed control of the process in the LonWorks/IP Virtual Device Network (VDN). It should be properly predicted and compensated. In this paper, a new distributed control scheme that can compensate for the effects of the time delay in the network is proposed. It is based on the PID controller augmented with the Smith predictor and disturbance observer. Designing methods for output feedback filter and disturbance observer are also proposed. Tracking position control experiment of a geared DC Servo motor is performed using the proposed control method. The performance of the proposed controller is compared with that of the Internal Model Controller (IMC) with the Smith predictor. The result shows that the performance is improved and guaranteed by augmenting a PID controller with both the Smith predictor and disturbance observer under the stochastic time delay in the LonWorks/IP VDN.

In this paper, position tracking control of an autonomous helicopter is presented. Velocity is controlled by using an optimal state controller LQR. A position control loop is added to form a PD controller. To minimize a position tracking error, neural network is introduced. The reference compensation technique as a neural network control structure is used, and a position tracking error of an autonomous helicopter is compensated by neural network installed in the remotely located ground station. Considering time delays between an autonomous helicopter and the ground station, simulation studies have been conducted. Simulation results show that the LQR with neural network compensation performs better than that of the LQR itself.

LonWorks over IP (LonWorks/IP) network is an integrated form of LonWorks device network and IP data network. LonWorks/IP network can offer ubiquitous access to the information on the factory floor and the real-time distributed control can be made possible. Timely response is inevitable for the real-time distributed control on the factory floor. Network induced uncertain time delay deteriorates the performance and stability of the real-time distributed control system on LonWorks/IP network. Therefore, time-varying uncertain time delay needs to be compensated for, in order to guarantee the stability and to improve the performance of the networked distributed control system. In this paper a control scheme based on disturbance observer and repetitive controller for the real-time distributed control on LonWorks/IP network with time-varying delay is proposed and tested through experiment. The result of the proposed control is compared with that of internal model controller (IMC) based on Smith predictor and disturbance observer. It is shown that the proposed control scheme can improve the tracking performance of the periodic reference.