• 사상체질의학회지
• /
• 제18권3호
• /
• pp.57-63
• /
• 2006

1. Objectives The Face is an important standard for the classification of Sasang Contitutions. Now We are developing 3D Face Automatic Recognition Apparatus to analyse the facial characteristics. This apparatus show us 3D image of man's face and measure facial figure. We should examine accuracy of position recognition in 3D Face Automatic Recognition Apparatus. 2. Methods We took a photograph of Face status with Land Mark 8 times using Face Automatic Recognition Apparatus. Each taking-photo, We span Face statusby 10 degree. At last time, We took a photograph of Face status's lateral face. And We analysed Error Averige of Distance between seven Land Marks. So We examined the accuracy of position recognition in 3D Face Automatic Recognition Apparatus at indirectly in degree changing of Face status. 3. Results and Conclusions According to degree change of Face status, Error Averige of Distance between Seven Land Marks is 0.1848mm. In conclusion, We assessed that accuracy of position recognition in 3D Face Automatic Recognition Apparatus is considerably good in spite of degree changing of Face status

• 로봇학회논문지
• /
• 제11권3호
• /
• pp.172-182
• /
• 2016

Lane-level vehicle positioning is an important task for enhancing the accuracy of in-vehicle navigation systems and the safety of autonomous vehicles. GPS (Global Positioning System) and DGPS (Differential GPS) are generally used in navigation service systems, which however only provide an accuracy level up to 2~3 m. In this paper, we propose a 3D vision based lane-level positioning technique which can provides accurate vehicle position. The proposed method determines the current driving lane of a vehicle by tracking the 3D position of traffic signs which stand at the side of the road. Using a stereo camera, the 3D tracking paths of traffic signs are computed and their projections to the 2D road plane are used to determine the distance from the vehicle to the signs. Several experiments are performed to analyze the feasibility of the proposed method in many real roads. According to the experimental results, the proposed method can achieve 90.9% accuracy in lane-level positioning.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.1152-1154
• /
• 2003

The needs of 3-D data have been increasing for various applications like visualization, 3-D modeling, planning and management as well as entertainment. Mobile mapping has become a quick and practical means for acquiring necessary 3-D data for above-mentioned applications. A mobile mapping system mainly consists of two main components, viz. data acquisition devices and positioning devices. The data acquisition devices consist of CCD cameras or/and laser scanners. The positioning devices consist of GPS, INS, Odometer (shaft encoder) and some other referencing devices. The overall accuracy of mobile mapping system depends on the accuracy of positioning devices and their integrated output. Though, GPS is the main input device for the position information, the signal is not available for the computation of position all the times in urban area. The GPS satellites are normally obstructed by high-rise buildings. Thus it is very important to understand the accuracy of such a system in different environments and means to solve such problems. We have developed a mobile mapping system called VLMS (Vehicle-borne Laser Mapping System), which consists of CCD Cameras, Laser scanners, GPS, INS and Odometer. In this paper, we will present and discuss the accuracy of this system with data acquired in different environments (open area, urban area, tunnel, express way etc) by analyzing the data with respect to other existing digital data.

• International journal of advanced smart convergence
• /
• 제9권3호
• /
• pp.232-238
• /
• 2020

In this paper, we study on aerial objects detection and position estimation algorithm for the safety of UAV that flight in BVLOS. We use the vision sensor and LiDAR to detect objects. We use YOLOv2 architecture based on CNN to detect objects on a 2D image. Additionally we use a clustering method to detect objects on point cloud data acquired from LiDAR. When a single sensor used, detection rate can be degraded in a specific situation depending on the characteristics of sensor. If the result of the detection algorithm using a single sensor is absent or false, we need to complement the detection accuracy. In order to complement the accuracy of detection algorithm based on a single sensor, we use the Kalman filter. And we fused the results of a single sensor to improve detection accuracy. We estimate the 3D position of the object using the pixel position of the object and distance measured to LiDAR. We verified the performance of proposed fusion algorithm by performing the simulation using the Gazebo simulator.

• 한국측량학회지
• /
• 제27권2호
• /
• pp.187-194
• /
• 2009

지상용 3차원 레이저 스캐너를 설계하고 개발하는데 있어서 위치 측정 결과의 정확성을 향상하기 위한 서보 모터의 선정과 서보 모터 FOC(Field Oriented Control) 제어 방식의 적용에 대한 연구이다. 개발 중인 지상용 3차원 레이저 스캐너는 360$^\circ$방위각과 270$^\circ$고도각의 스캔 범위를 가지고 있다. 이의 구현은 서보 모터인 방위각 모터와 고도각 모터의 정밀한 서보 모터 제어를 통해 실현된다. 연구 결과 FOC(Field Oriented Control)제어를 통해서 모터의 일정한 토크를 유지하면서 모터의 동작 위치 정확도를 향상할 수 있음을 확인하였다. 이러한 모터 제어는 지상용 3차원 레이저 스캐너뿐만 아니라 로보틱 토털스테이션에도 적용이 가능 할 것으로 사료된다.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2011년도 추계학술대회
• /
• pp.173-175
• /
• 2011

본 논문에서는 얼굴의 3차원 위치와 방향을 추적하여 3D 물체를 다각도에서 볼 수 있는 사용자 인터페이스를 제시한다. 구현된 사용자 인터페이스는 사용자가 상하좌우로 얼굴을 움직였을 때, 얼굴의 3차원 위치 좌표를 이용하여 사용자가 움직이는 방향으로 물체를 이동시킨다. 그 뒤 사용자가 상하(pitch)좌우(yaw)로 얼굴을 회전시켰을 때, 얼굴의 Euler angle값을 이용하여 얼굴의 회전각만큼 물체를 회전시켜 물체의 측면을 제공한다. 다양한 위치와 방향에 사용자가 있을 때 물체의 움직임의 정확성과 반응성을 실험한 결과 시각화가 잘 됨을 확인하였다.

• Journal of Astronomy and Space Sciences
• /
• 제35권4호
• /
• pp.227-233
• /
• 2018

This study presents the generation and accuracy assessment of predicted orbital ephemeris based on satellite laser ranging (SLR) for geostationary Earth orbit (GEO) satellites. Two GEO satellites are considered: GEO-Korea Multi-Purpose Satellite (KOMPSAT)-2B (GK-2B) for simulational validation and Compass-G1 for real-world quality assessment. SLR-based orbit determination (OD) is proactively performed to generate orbital ephemeris. The length and the gap of the predicted orbital ephemeris were set by considering the consolidated prediction format (CPF). The resultant predicted ephemeris of GK-2B is directly compared with a pre-specified true orbit to show 17.461 m and 23.978 m, in 3D root-mean-square (RMS) position error and maximum position error for one day, respectively. The predicted ephemeris of Compass-G1 is overlapped with the Global Navigation Satellite System (GNSS) final orbit from the GeoForschungsZentrum (GFZ) analysis center (AC) to yield 36.760 m in 3D RMS position differences. It is also compared with the CPF orbit from the International Laser Ranging Service (ILRS) to present 109.888 m in 3D RMS position differences. These results imply that SLR-based orbital ephemeris can be an alternative candidate for improving the accuracy of commonly used radar-based orbital ephemeris for GEO satellites.

• 센서학회지
• /
• 제32권4호
• /
• pp.232-237
• /
• 2023

This paper presents a system for estimating the position of a magnet using a magnetic sensor. An algorithm is presented to analyze the waveform and output voltage values of the magnetic field generated at each position when the magnet moves and to estimate the position of the magnet based on the analyzed data. Here, the magnet is sufficiently small to be inserted into a blood vessel and has a micro-magnetic field of hundreds of nanoteslas owing to the small size and shape of the guide wire. In this study, a highly sensitive magneto-impedance (MI) sensor was used to detect these micro-magnetic fields. Nine MI sensors were arranged in a 3×3 configuration to detect a magnetic field that changes according to the position of the magnet through the MI sensor, and the voltage value output was polynomially regressed to specify a position value for each voltage value. The accuracy was confirmed by comparing the actual position value with the estimated position value by expanding it from a 1D straight line to a 3D space. Additionally, we could estimate the position of the magnet within a 3% error.

• 한국재난정보학회 논문집
• /
• 제15권3호
• /
• pp.427-439
• /
• 2019

연구목적: 다양한 목적으로 생성되는 무인비행체 기반의 공간정보를 서로 다른 SW로 생성하고, 정사영상 및 DSM의 위치정확도 분석과 3D mesh의 텍스처 매핑을 비교 분석하고자 하였다. 연구방법: 서로 다른 두 개의 SW를 이용하여 동일한 무인항공영상 데이터를 처리하고, 공간정보를 생성하였다. 생성된 공간정보 중 정사영상과 DSM은 수평위치 및 수직위치 오차의 RMSE를 계산함으로써 정량적 분석을 수행하고, 정성적 분석을 수행함으로써 무인항공사진측량 SW의 공간정보 생성 결과를 비교분석하고자 하였다. 연구결과: 각각의 SW로 생성된 정사영상 및 DSM의 위치정확도에서는 큰 차이가 없었으며, 3D mesh의 텍스쳐 매핑에서 차이를 보였다. 3D mesh의 생성에는 무인항공사진측량 SW가 영향을 미치는 것을 알 수 있었다. 결론: 무인비행체 기반의 공간분석을 위한 정사영상, DSM의 생성에는 SW에 따른 영향이 없는 것으로 나타났으나 3D 가시화를 목적으로 할 경우에는 SW에 따라 텍스처 매핑 결과가 다르게 나타나는 것을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
• /
• pp.832-836
• /
• 1988

"Motion Stereo" is quite useful for visual guidance of the robot, but most range finding algorithms of motion stereo have suffered from poor accuracy due to the quantization noise and measurement error. In this paper, 3-D position estimation and refinement scheme is proposed, and its performance is discussed. The main concept of the approach is to consider the entire frame sequence at the same time rather than to consider the sequence as a pair of images. The experiments using real images have been performed under following conditions : hand-held camera, static object. The result demonstrate that the proposed nonlinear least-square estimation scheme provides reliable and fairly accurate 3-D position information for vision-based position control of robot. of robot.