• Title/Summary/Keyword: 3D navigation error

Search Result 93, Processing Time 0.021 seconds

A Study of High Precision Position Estimator Using GPS/INS Sensor Fusion (GPS/INS센서 융합을 이용한 고 정밀 위치 추정에 관한 연구)

  • Lee, Jeongwhan;Kim, Hansil
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.49 no.11
    • /
    • pp.159-166
    • /
    • 2012
  • There are several ways such as GPS(Global Positioning System) and INS (Inertial Navigation System) to track the location of moving vehicle. The GPS has the advantages of having non-accumulative error even if it brings about errors. In order to obtain the position information, we need to receive at least 3 satellites information. But, the weak point is that GPS is not useful when the 혠 signal is weak or it is in the incommunicable region such as tunnel. In the case of INS, the information of the position and posture of mobile with several Hz~several hundreds Hz data speed is recorded for velocity, direction. INS shows a very precise navigational performance for a short period, but it has the disadvantage of increasing velocity components because of the accumulated error during integration over time. In this paper, sensor fusion algorithm is applied to both of INS and GPS for the position information to overcome the drawbacks. The proposed system gets an accurate position information from experiment using SVD in a non-accessible GPS terrain.

Performance analysis of WA-DGNSS in Korea with the selection of reference stations (한국에서의 기준국 네트워크 선정에 따른 GNSS 광역보정시스템 성능 분석)

  • Han, Deokhwa;Yun, Ho;Kee, Changdon
    • Journal of Navigation and Port Research
    • /
    • v.37 no.4
    • /
    • pp.367-373
    • /
    • 2013
  • Wide area differential GNSS(WA-DGNSS) collects GPS measurements from the several reference stations and estimates 3-D satellite orbit error, satellite clock error, ionospheric delay. These correction messages are broadcasted to user, then user can have more accurate and reliable position estimates. The performance of WA-DGPS can be changed depending on the position of reference stations. To select proper reference stations, performance analysis with the change of reference stations is necessary. In this paper, changing the geographical location of reference stations, we carried out simulation based test and show the performance of WA-DGNSS in Korea.

Performance Analysis and Equivalent Circuit Extraction for Magnetic Resonance Type Wireless Power Transfer (자기공진방식 무선전력전송 등가회로 추출 및 특성 분석)

  • Park, Dae Kil;Kim, Young Hyun;Koo, Kyung Heon
    • Journal of Advanced Navigation Technology
    • /
    • v.21 no.4
    • /
    • pp.371-376
    • /
    • 2017
  • In this paper, we propose a magnetic resonant WPT(wireless power transfer) scenario using a large coil resonating at 6.78 MHz, and compare the characteristics through a three-dimensional electromagnetic field simulation and a magnetic resonant WPT equivalent circuit. The magnetic resonant WPT equivalent circuit proposed in this paper considers the parasitic capacitance generated between the coils in addition to the conventional equivalent circuit. Based on this analysis, we fabricated the magnetic resonant WPT coil and compared it with simulation prediction. As a result of comparison, the transfer characteristics and the resonance frequency shift can be predicted. Error proposed characteristics of equivalent circuit for the magnetic resonant WPT and the measured values are estimated to be ${\Delta}{\mid}S11{\mid}=1.31dB$ and ${\Delta}{\mid}S21{\mid}=1.21dB$, respectively.

Alternative Positioning, Navigation and Timing Using Multilateration in a Terminal Control Area (접근관제구역에서 다변측정감시시스템을 이용한 대안항법 방안 연구)

  • Jo, Sanghoon;Kang, Ja-young
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.23 no.3
    • /
    • pp.35-41
    • /
    • 2015
  • Multilateration(MLAT) is commonly used in civil and military surveillance applications to accurately locate an aircraft, vehicle or stationary emitter. MLAT calculates the TDOA of signals by transmitted aircraft and determines the aircraft's location. With more than four receivers it is possible to estimate the 3D position of the aircraft by calculating the intersection of the resulting hyperbolas and the system integrity. In this study, our objectives are to apply MLAT technique to Jeju terminal control area and to propose a MLAT receiver network to properly estimate the positions of aircraft approaching this area. Based on computer simulations, we determine locations of ground receivers in Jeju terminal control area, calculate estimated position errors of the aircraft with respect to the selected receiver networks, and find the best receiver network with the least position error.

Implementation of Path Finding Method using 3D Mapping for Autonomous Robotic (3차원 공간 맵핑을 통한 로봇의 경로 구현)

  • Son, Eun-Ho;Kim, Young-Chul;Chong, Kil-To
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.14 no.2
    • /
    • pp.168-177
    • /
    • 2008
  • Path finding is a key element in the navigation of a mobile robot. To find a path, robot should know their position exactly, since the position error exposes a robot to many dangerous conditions. It could make a robot move to a wrong direction so that it may have damage by collision by the surrounding obstacles. We propose a method obtaining an accurate robot position. The localization of a mobile robot in its working environment performs by using a vision system and Virtual Reality Modeling Language(VRML). The robot identifies landmarks located in the environment. An image processing and neural network pattern matching techniques have been applied to find location of the robot. After the self-positioning procedure, the 2-D scene of the vision is overlaid onto a VRML scene. This paper describes how to realize the self-positioning, and shows the overlay between the 2-D and VRML scenes. The suggested method defines a robot's path successfully. An experiment using the suggested algorithm apply to a mobile robot has been performed and the result shows a good path tracking.

Performance Improvement Technique of Three-Dimensional Guidance Law Suitable for Ammunition (포발사 탄약에 적합한 3차원 유도법칙의 성능개선 기법)

  • Shin, Seung-Je;Kim, Whan-Woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.46 no.8
    • /
    • pp.631-638
    • /
    • 2018
  • In this paper, we propose a method to improve the performance by guidance technique and applying it to the precision guided ammunition. The proposed method is a technique designed to reduce the target error of ammunition by reducing the projectile error without analyzing the motion characteristics of the shot. This technique is applied to the moving average filter technique which is widely used as signal processing technique to reduce the fluctuation of the output of the inboard mounting inertial sensor caused by the rotation and the coning motion of the ammunition. In order to compare the performance of the applied technique including the simple 3D guided control technique and the proposed improvement technique. It is confirmed that the application of this technique improves the accuracy of impact of the cannon - launched ammunition with severe environmental conditions and irregular motion characteristics unlike the missile.

High Efficiency Power Amplifier applied to 5G Systems (5G 시스템에 적용되는 고효율 전력증폭기)

  • Young Kim
    • Journal of Advanced Navigation Technology
    • /
    • v.27 no.2
    • /
    • pp.197-202
    • /
    • 2023
  • This paper presents the design method and electrical characteristics of a high-efficiency power amplifier for a 50 Watts class repeater applied to a 5G system and used in in-building, subway, and tunnel. GaN was used for the termination transistor of the power amplifier designed here, and intermodulation signals were removed using DPD to satisfy linearity. In addition, in order to handle various requirements such as amplifier gain control and alarm processing required in the 5G system, the microprocessor is designed to exist inside the power amplifier. The amplifier manufactured to confirm the electrical performance of the power amplifier satisfying these conditions satisfied 46.5 dBm and the overall efficiency of the amplifier was 37%, and it was confirmed that it satisfied various alarm conditions and electrical characteristics required by telecommunication companies.

Accuracy Assessment of Aerial Triangulation of Network RTK UAV (네트워크 RTK 무인기의 항공삼각측량 정확도 평가)

  • Han, Soohee;Hong, Chang-Ki
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.38 no.6
    • /
    • pp.663-670
    • /
    • 2020
  • In the present study, we assessed the accuracy of aerial triangulation using a UAV (Unmanned Aerial Vehicle) capable of network RTK (Real-Time Kinematic) survey in a disaster situation that may occur in a semi-urban area mixed with buildings. For a reliable survey of check points, they were installed on the roofs of buildings, and static GNSS (Global Navigation Satellite System) survey was conducted for more than four hours. For objective accuracy assessment, coded aerial targets were installed on the check points to be automatically recognized by software. At the instance of image acquisition, the 3D coordinates of the UAV camera were measured using VRS (Virtual Reference Station) method, as a kind of network RTK survey, and the 3-axial angles were achieved using IMU (Inertial Measurement Unit) and gimbal rotation measurement. As a result of estimation and update of the interior and exterior orientation parameters using Agisoft Metashape, the 3D RMSE (Root Mean Square Error) of aerial triangulation ranged from 0.153 m to 0.102 m according to the combination of the image overlap and the angle of the image acquisition. To get higher aerial triangulation accuracy, it was proved to be effective to incorporate oblique images, though it is common to increase the overlap of vertical images. Therefore, to conduct a UAV mapping in an urgent disaster site, it is necessary to acquire oblique images together rather than improving image overlap.

Development of the EM Wave Absorber for ETC of ITS (ITS의 ETC용 전파흡수체 개발)

  • Song, Young-Man;Choi, Chang-Mook;Lee, Dae-Hee;Kim, Dong-Il
    • Journal of Navigation and Port Research
    • /
    • v.31 no.8
    • /
    • pp.671-674
    • /
    • 2007
  • In this paper, the EM wave absorber was designed and fabricated for ETC system, because ETC system has some problems including signal error and system-to-system interference. We fabricated some samples in different composition ratio of MnZn-ferrite, Carbon and CPE, confirmed that optimum composition ratio of Mn2n-ferrite, Carbon, CPE was 40 : 15 : 45 wt%. Complex relative permittivity and complex relative permeability was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using complex relative permittivity and permeability. The EM wave absorber was fabricated based on simulated data Simulated and measured values agree well. As a result, the developed EM wave absorber has a thickness of 3.38 mm and absorption ability over 20 dB at 5.8 GHz.

Developing VR-based Sailor Training Platform Authoring Tool (가상현실 기반 선원 훈련 플랫폼 저작도구 개발)

  • Jung, Jinki;Lee, Hyeopwoo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2016.05a
    • /
    • pp.181-185
    • /
    • 2016
  • In this paper we propose a VR-based Sailor Training Platform Authoring Tool which efficiently trains sailors in immersive ways. Proposed authoring tool consists of virtual environment reconstruction that imports real ship indoor environment into virtual environment and script editing which is able to implement various scenarios in emergency based on just drag-and-drop interface. The aim of importing real ship environment and supporting various VR devices is to enhance immersiveness and training so that trainees can deal with serious emergency events. Also the usefulness of the interface enables to reduce the cost of making training materials. Throughout scenario editing interface, the proposed authoring tool supports the editing of multi-user scenario and setting individual task for the evaluation.

  • PDF