Geomagnetic Sensor Research Articles

임베디드 기반의 다차원 위치정보 추출 및 저장시스템 개발

Lost fishing gears become a major cause of marine pollution, and many policy and technical efforts have been conducted for that. For efficient retrieving lost fishing gears in underwater, It is important to know the current position. Using GPS in the sub-sea environment is impossible and localization requires the use of special systems, and mobility due to water currents for underwater localization also has to be considered. In this paper, described with respect to the system for a self-generated location informations without using an external signal, such as a GPS and Sonar and storing them. Using the characteristics of the geomagnetic and INS principle, proposed informations and a way for estimating self position during movement. Embedded based system suggested and implemented in this study is tested for validating it's functionality. 키워드 : 수중 위치추정, 관성항법, 자이로센서, 가속도센서, 자자기센서 Key word : Underwater Localization, INS, Gyro Sensor, Acceleration Sensor, Geomagnetic Sensor Journal of the Korea Institute of Information and Communication Engineering 임베디드 기반의 다차원 위치정보 추출 및 저장시스템 개발

Application of motion sensors for beam-tracking of mobile stations in mmWave communication systems.

In a millimeter wave (mmWave) communication system with transmit/receive (Tx/Rx) beamforming antennas, small variation in device behavior or an environmental change can destroy beam alignment, resulting in power loss in the received signal. In this situation, the beam-tracking technique purely based on the received signal is not effective because both behavioral changes (rotation, displacement) and environmental changes (blockage) result in power loss in the received signal. In this paper, a motion sensor based on microelectromechanical systems (MEMS) as well as an electrical signal is used for beam tracking to identify the cause of beam error, and an efficient beam-tracking technique is proposed. The motion sensors such as accelerometers, gyroscopes, and geo-magnetic sensor are composed of an attitude heading reference system (AHRS) and a zero-velocity detector (ZVD). The AHRS estimates the rotation angle and the ZVD detects whether the device moves. The proposed technique tracks a beam by handling the specific situation depending on the cause of beam error, minimizing the tracking overhead. The performance of the proposed beam-tracking technique is evaluated by simulations in three typical scenarios.

WTrack: HMM-based walk pattern recognition and indoor pedestrian tracking using phone inertial sensors

Indoor tracking systems have become very popular, wherein pedestrian movement is analyzed in a variety of commercial and secure spaces. The inertial sensor-based method makes great contributions to continuous and seamless indoor pedestrian tracking. However, such a system is vulnerable to the cumulative locating errors when moving distance increases. Inaccurate heading values caused by the interference of body swing of natural walking and the geomagnetic disturbances are the main sources of the accumulative errors. To reduce such errors, additional infrastructure or highly accurate sensors have been used by previous works that considerably raise the complexity of the architecture. This paper presents an indoor pedestrian tracking system called WTrack, using only geomagnetic sensors and acceleration sensors that are commonly carried by smartphones. A fine-grained walk pattern of indoor pedestrians is modeled through Hidden Markov Model. With this model, WTrack can track indoor pedestrians by continuously recognizing the pre-defined pedestrians' walk pattern. More importantly, WTrack is able to resist both the interference of body swing of natural walking and the geomagnetic disturbances of nearby objects. Our experimental results reveal that the location error is <2 m, which is considered adequate for indoor location-based-service applications. The adaptive sample rate adjustment mode further reduces the energy consumption by 52 % in comparison, as opposed to the constant sampling mode.

Development of Positioning System Based on Auto VRS-GPS Surveying

There has been a need for replacing human labors with a robot in such dangerous and hard jobs of various construction sites. For that reason, many researches have been made about the high quality robot, which performs its duty instead of human labors. This study is about auto surveying system development based on VRS-GPS which enables autodriving in dangerous areas where it’s difficult for humans to measure directly. This study is about the auto-surveying system development, based on VRS-GPS, which enables auto-drive in dangerous areas, whereas difficult for humans to measure directly. The GPS is made with GRXI and SHC250 controllers of the SOKKIA company. The auto surveying system is composed of DPS module, geomagnetism sensor, bluetooth, gimbals, IMU, etc to automatic drive via enter into a route of position. The developed auto surveying system has installed the carmeras for front and vertical axis as well as systems to grasp situation of surveying with smartphone in real time. The result from analysed RMSE of auto surveying system and VRSGPS surveying is 0.0169m of X-axis and 0.0246m of Y-axis.

Error Compensation of Geomagnetic Azimuth Sensor Based on Model Identification

Error Compensation of Geomagnetic Azimuth Sensor Based on Model Identification

J1620201 全身装着型慣性センサと接触センサによる非放物跳躍運動の計測([J162-02]医療・健康・福祉のためのセンシングおよびロボティクス(2))

The motion analysis method of the non-parabolic jumping motion using wearable sensor is proposed. The wireless inertial measurement sensor unit version2 (WIMU2) uniquely developed consists of 3D accelerometer, 3D gyroscope, 3D geomagnetic sensor, 9 AD channels, memory and wireless communication module. Twelve WIMU2 are mounted on upper body and lower one. The posture of the body is estimated using the axis direction of sensor that is modified by extended Kalman filter. When the hand or foot touches the wall or ground, touching position is considered as the origination of calculation, and 3D posture of whole body is constructed. The trajectory of the body during jumping is calculated by the double integration of measured acceleration from the trunk. To confirm the efficacy of proposed motion analysis method, one subject pushes the wall forward during jumping and lands backward. The experimental result shows that the proposed motion analysis method is able to estimate the posture and trajectory of the whole body during non-parabolic jumping motion.

특수목적을 위한 이동형 영상 터미널 장비의 추적안테나 시스템에 적용하기 위한 방위각보정 알고리즘 구현

In this paper, we proposed on the azimuth correction method for a line-of-sight data-link tracking antenna system. Tracking antenna system is essential to maintain line-of-sight between moving object and data-link equipment. In order to calculate the azimuth and elevation between the moving object and antenna system, we used GPS data. also to match the each coordinate systems, we used geomagnetic sensor or beacon. However, the geomagnetic disturbance-prone terrain in places difficult to correct calibration. The first step, finds the location of the strongest RF signal, we should remember the difference between the reference point and the detected position of the antenna. The second step, we could communicate each other. And the azimuth angle is calculated by GPS values. Despite the geomagnetic interference, we can correct the azimuth angle quickly and easily.

VRS-GPS 자동측위시스템을 이용한 해안매립지 측량

최근 건설현장에서는 3D 기피 현상으로 자동화에 대한 관심이 증대되고 있다. 본 연구는 개발된 VRS-GPS 기반 자동 측위시스템으로 해안매립지를 측량한 결과에 관한 연구이다. 자동측위시스템에 설치된 GPS는 GRX1 수신기와 SHC250 컨트롤러를 사용하였다. 자동측위시스템은 DSP모듈, 지자기센서, 블루투스, 짐벌, IMU등으로 구성되어 있으며, 입력된 위치경로로 자동주행이 가능하도록 하였다. 개발된 GPS 자동측위시스템은 전방과 구심점 관측 카메라를 설치하여 측량상황을 스마트폰으로 실시간으로 파악 할 수 있도록 하였다. 개발된 자동측위시스템을 건설현장에 적용하여 실험한 결과 평균제곱근오차는 X축에서 0.009m, Y측에서 0.010m, 높이는 0.002m로 나타났으며, 현장적용 가능성이 있음을 확인하였다. Recent construction in the field of 3D aversion is increasing interest in automation. This study is results about survey of the coastal landfill using automatic VRS-GPS surveying system. GPS is made with GRXI and SHC250 controller. Automatic surveying system is composed of DPS module, geomagnetism sensor, bluetooth, gimbals, IMU, etc and enables an automatic driving via entered into a route of position. The developed auto surveying system has installed the front and camera for vertical axis and can grasp situation of surveying with smartphone in real time. The comparative result between surveyed result with repetition method auto VRS-GPS surveying system observed surveyed result with VRS-RTK has shown that average error of x-axis is 0.009m, average error of y-axis, 0.010m and average error of height, 0.002m. This possibility was confirmed that field application.

Development and Functional Evaluation of an Upper Extremity Rehabilitation System Based on Inertial Sensors and Virtual Reality

An extremity rehabilitation program was proposed based on inertial measurement units (IMU) and virtual reality. A single IMU consists of a three-axis accelerometer, gyroscope, and geomagnetic sensors. One IMU is attached to the upper arm (master) and another to the forearm (slave). The IMUs are connected using a distributed sensor network implemented with interintegrated circuit communication. The motion-tracking algorithm running on a PC tracks the subject's hand based on the estimated IMU orientation and segment lengths through forward kinematics. The training contents, including various dynamic movements and static holds, were designed to evaluate the spatiotemporal aspects of the subject's functionality. The system was tested on a group of healthy subjects and a group with a simulated stiff elbow, allowing the evaluations to be quantitatively differentiated. The stiff elbow was simulated by taping the elbow to restrict the range of elbow motion. We expect the patients to be able to assess their own status without assistance from a therapist and select appropriate training methods to increase their rehabilitation effectiveness. Future studies will verify the availability and reliability of the upper extremity rehabilitation program for patients with a hemiplegia, leading to the development of an upper extremity rehabilitation program for three-dimensional movements of the upper extremities.

Informazioni dirette ed indirette nell’organizzazione dello spazio urbano

The relationship between new technologies and urban space has become, especially with the introduction of the concept of smart city, the key in the definition of management options in the city itself. The opportunities provided by the use of new technologies to manage the complexity of multiple aspects on the relationship between city and people can address strategies and innovation in order to improve the quality of life of the inhabitants. In smart cities different groups of people with different instances can be directly involved in the transformation process and the planners’ choices can be supported by information that once would have required costly research. This possibility is granted by the availability of great quantities of data that can be collected and analyzed. Direct information can be gathered by multiple sensors (accelerometer, a geomagnetic sensor, and proximity sensor, etc.) that offer an immediate evaluation of a specific phenomenon. At the same time other aspects can be evaluated by information obtained in social networks: these can contribute to the definition of urban design as the result of a multi criteria analyses. The way to achieve these strategies is a process of interaction between spatial reality and perceived reality made available by passive forms of participation that can help planners in understanding territorial actors’ / territorial users’ needs and requirements. Through this approach, the design and decisions about urban space are not to be indifferent to the needs expressed by various categories of population.

A Metadata Design for Augmented Broadcasting and Testbed System Implementation

Augmented reality (AR) is a popular service in mobile devices, and many AR applications can be downloaded from app stores. As TV broadcasting has continued to integrate with the Internet, it has become an area in which the AR concept is able to reside, although in a simple form, such as an advertisement placed in the static region of a scene. There are some restrictions against TV broadcasting realizing AR since TVs are fixed devices and typically do not have GPS, geomagnetic, or acceleration sensors, which are standard equipment in mobile devices. However, the desire to experience AR on a large TV screen has triggered research and development for an ideal AR business model and service type. This paper introduces several use cases for augmented broadcasting services and also presents an augmented broadcasting metadata scheme designed for a broadcasting environment. We also verify some of the use cases and an augmented broadcasting metadata scheme in an implemented augmented broadcasting system based on a hybrid TV platform.

New indoor navigation system for visually impaired people using visible light communication

In this study, we propose an indoor navigation system that utilizes visible light communication technology, which employs LED lights and a geomagnetic correction method, aimed at supporting visually impaired people who travel indoors. To verify the effectiveness of this system, we conducted an experiment targeting visually impaired people. Although acquiring accurate positional information and detecting directions indoors is difficult, we confirmed that using this system, accurate positional information and travel direction can be obtained utilizing visible light communication technology, which employs LED lights, and correcting the values of the geomagnetic sensor integrated in a smartphone.

무선통신기반 위치인식을 이용한 실내 내비게이션 시스템에 관한 연구

Recently, navigation systems based on wireless communication have been applied to the internal structures such as building or ship. If a stable azimuth information is obtained, these systems can effectively guide the direction of the user`s progress through the information and then can improve the performance of guidance. Since conventional method which has acquired an azimuth information using geomagnetic and acceleration sensor(azimuth sensor hereafter) is sensitive to the effects of the magnetic field, it has unstable error range according to the surrounding environment. In order to improve these problems, this paper presents a new relative azimuth estimation algorithm using the displacement of a mobile node and its rotation angle based on Wireless communication. For the performance assessment of the proposed algorithm, experiments using rotating arm are performed and the results are confirmed that the proposed system can estimate the relative azimuth without using additional sensors.

Positioning performance evaluation of magnetic contour matching under different accuracy of sensor

The accuracy of geomagnetic reference map, geomagnetic sensor, and inertial navigation system is the key factor which affects the reliability of magnetic contour matching (MAGCOM) system. In order to improve the reliability of MAGCOM, the influence of the sensor's accuracy on the matching success rate has been studied. For different geomagnetic reference maps, the factors and their physical mechanism affecting matching success rate have been analyzed, the factors are geomagnetic sensor error, velocity error, and heading angle error. The error range of sensors was determined by the simulation computing which was based on a practical system and a simulation experimentation was implemented by using the geomagnetic reference map. The simulation results show that MAGCOM can allow the velocity error 0.14 m/s, the heading angle error 0.6 and the standard deviation of geomagnetic sensor noise 11 nT, when the matching success rate is 90%.

A comprehensive sounding of the ionospheric HF radio link from Antarctica to Spain

Since 2003, our group has been investigating the performance of different transmission techniques for low‐power low‐interference High Frequency (HF) ionospheric communication systems. Specifically, we have focused on the link between the Spanish Antarctic Station (SAS) Juan Carlos I in Livingston Island and Ebro Observatory (OE) in Spain, in order to transmit the data gathered from some geomagnetic sensors. These transmission techniques require a valuable knowledge of the channel behavior, thus a comprehensive narrowband and wideband sounding of the ionospheric channel is needed. Some significant improvements both in the system and in the signal processing have been done to achieve this goal. The analysis time and the frequency band have been extended to 24 hours per day and to the whole HF band (2‐30 MHz). Moreover, new measurements of the absolute propagation time and the Doppler frequency shift are introduced. In this paper, the sounding results obtained using the new system are presented.

Validation of Indoor Navigation System for Visually Impaired People

In this study, we propose an indoor navigation system that utilizes visible light communication technology, which employs LED lights and a geomagnetic correction method, aimed at supporting visually impaired people who travel indoors. To verify the effectiveness of this system, we conducted an experiment targeting visually impaired people. Although acquiring accurate positional information and detecting directions indoors is difficult, we confirmed that using this system, accurate positional information and travel direction can be obtained utilizing visible light communication technology, which employs LED lights, and correcting the values of the geomagnetic sensor integrated in a smartphone.

The Design and Error Compensation Research of 3-Axis Electronic Compass Installed in Small Muti-Rotors Unmanned Aerial Vehicle

A 3-axis electronic compass is designed for small multi-rotors unmanned vehicle. The STM32F103 is used as E-compass’ CPU, and ADXL345 and MAG3110 is used as the acceleration and geomagnetic sensor. The E-compass’ software is programmed by using IAR EWARM. For outdoor applications, the ellipsoid assumption theory is simply proved and used for E-compass’ self-calibration. By using the zero-bias adjustment for pre-calibration and the fitellipsoid compensation for precise calibration, the E-compass’ precision is nearly 1 degree.

IEEE 802.15.4a와 센서를 이용한 실시간 실내위치인식 시스템

고정노드 2개를 사용하는 이변측위 방법은 건물이나 선박의 복도와 같은 좁은 공간에서 실시간 실내위치인식 시스템 분야에 사용되고 있다. 하지만 이러한 공간에서 고정노드 간 거리가 멀어지거나 장애물이 있을 경우 위치정보 수신율 저하로 인하여 이동노드(사용자)의 위치 추정이 어렵게 된다. 본 논문에서는 이와 같은 문제를 보완하기 위하여 IEEE 802.15.4a Chirp 신호를 기반으로 사용자에게 부착된 센서를 통하여 위치를 계산할 수 있는 보폭 측정 알고리즘을 이용하는 새로운 실시간 실내위치인식 시스템을 제안한다. 제안한 시스템은 다리길이 측정을 위한 초음파센서, 사용자의 방향을 인식하는 지자기 센서 및 다리사이 각을 획득하기 위한 관성센서로 구성된다. 실험 결과 제안한 시스템은 통신도달성이 결여된 구간에서 기존 실내위치인식 방법에 비해 2배 이상 정교한 결과를 나타내었다.

Geomagnetic sensors based on Metglas/PZT laminates

A potential geomagnetic-field sensor is proposed on the basis of an optimal 2D configuration of magnetoelectric Ni-based Metglas/PZT laminates. This sensor can perfectly serve to measure both the strength and the orientation of the earth's magnetic field. An incredibly high ME-voltage response of 0.871V/Oe to the geomagnetic field with a resolution of 3×10−4Oe has been achieved for composite laminates with a size of 15mm×1mm. With respect to the field inclination, an angular sensitivity of 3.86×10−3V/degree and an angular resolution of 10−1 degree have been determined. This simple and low-cost magnetic-field sensor is promising for applications not only as novel smart compasses and in global positioning devices, but also as magnetic biosensors.

스마트폰에서 다중데이터를 이용한 측위시스템 구현

Recently, navigation system is used to inform users of vehicle location and driving direction, moving distance and so on. This navigation uses GPS sensor for current location determination. The GPS sensor will determinate current coordinates by using triangulation algorithm. This characteristic bring about that the GPS signal is not available in the shadow region such as tunnel and urban canyon. Moreover, Even though the signal is available, inherent positional error rate of the GPS often results in the dislocation of vehicle. To solve, these problems, a new positioning system is proposed in the paper. The System utilizes geomagnetic sensors of smartphone, speed information of CAN of vehicle though bluetooth and WiFi APs for GPS shadow area. The experimental test shadows that the proposed system using multiple data is able to determine the position of vehicle in GPS shadow areas.