• Journal of Korean Society for Geospatial Information Science
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• v.3 no.1 s.5
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• pp.37-44
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• 1995

Cartesian coordinate systems used in national base map have 3 zones. If these coordinate systems are used at navigable digital maps without modifications, the edge-matching errors will occur near the edge of two zones. Therefore, it's required to eliminate separate zones of national plane coordinates system suitable far navigable digital map, we choose TM projection that is used at national base map but changed the location and the scale distortion of antral meridian.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.41-48
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• 2019

This paper deals with a method of aligning an aircraft fuselage and an inertial navigation sensor using three-dimensional coordinates obtained by an optical method. In order to verify the feasibility, we introduce the method to accurately align the coordinate system of the inertial navigation sensor and the aircraft reference coordinate system. It is verified through simulation that reflects the error level of the measuring device. In addition, optimization method based alignment algorithm is proposed for connection between optical sensor and inertial navigation sensor.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1938-1939
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• 2011

본 논문에서는 랜드마크의 시선각 측정값을 이용하여 3D 비전항법해를 계산하기 위한 항법방정식을 유도하고 항법해 결정 방법을 보여준다. 먼저, 카메라좌표계에서 측정한 시선각과 항법좌표계의 관계를 이용하여 3차원 항법방정식을 유도하였으며 항법해를 계산하기 위해서는 최소한 3개 이상의 랜드마크를 관측해야함을 보였다. 또한 논문에서는 항법방정식과 기하학을 이용하여 항체의 위치 및 자세를 계산하는 과정을 상세하게 기술한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.6
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• pp.463-472
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• 2017

Inertial Navigation System Alignment is the process to determine direction cosine matrix which is the transformation matrix between the INS body frame and navigation frame. INS initial position value is necessary to INS attitude calculation, so that user should wait until he get such value to start the INS alignment. To remove the waiting time, we propose an alignment algorithm that immediately starts after the INS power on by using pseudo initial position input and then is completed with attitude error compensation by entering true position later. We analyse effect of INS sensor error on attitude in process of time and verify the performance and usefulness of the close-loop alignment algorithm which corrects attitude error from the change of initial position.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.171-178
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• 2008

Galileo is the Europe's global navigation satellite system corresponding to the GPS. The GIOVE-A test experiment has been finished and the second test satellite GIOVE-B will be launched soon. The integration of GPS and Galileo lead an increase of visible satellite number. We can obtain an improved navigation performance in signal blocked area such as urban or forest. GPS and Galileo have each time-coordinate system and use the different error model to calculate the navigation solution. In this paper, we studied on GPS and Galileo channel error model and time-coordinate system. Using this result, we implement the integrated navigation algorithm. In simulation, we analyzed the navigation error caused by time and coordinate disagreement and verified performance of integrated navigation algorithm in terms of visible satellite number, DOP(Dilution of Pression) and position error.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1890-1897
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• 2022

In this paper, we design a navigation filter for an underwater glider. Underwater gliders are low-cost, reusable, and can be used for a long time. Two types of filters are designed considering characteristics such as small size, low cost, and low power. The navigation filter estimates the reference velocity of the underwater glider's body frame based on the minimum sensor output. The sensor configuration of the first filter consists of an accelerometer, a magnetometer, and a depth sensor. the second filter include extra a gyroscope in the same configuration. The estimated velocity is fused with the attitude, converted into the velocity of the navigation frame and finally the position is estimated. To analyze the performance of the proposed filter, analysis was performed using Monte Carlo numerical analysis method, and the results were analyzed with standard deviation (1σ). Standard deviations of each filter's position error are 334.34m, 125.91m.

• ICROS
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• v.16 no.1
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• pp.51-55
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• 2010

제어 및 로봇 응용에서 이동체의 위치, 속도, 그리고 자세 정보를 획득하는 기능은 매우 중요한 여할을 수행한다. 위치, 속도, 그리고 자세 정보는 통틀어 항법정리라 통칭되며 전파센서, 영상센서, 혹은 관성센서 등 다양한 센서들의 조합에 의하여 획득될 수 있다. 항법정보의 획득에 있어서 특히 관성센서는 다양한 센서들의 조합에 있어서 가장 중요한 역할을 수행하는데 이는 관성센서가 다른 센서들과는 달리 주변의 조명 환경, 전파환경, 그리고 고의적인 외란에 강인한 특성을 지니며, 이동체의 빠른 운동을 세밀하게 수치화하여 표현할 수 있기 때문이다. 본 고에서는 이와 같은 장점을 지닌 관성센서의 출력을 정확하게 다루기 위해 명확한 이해가 요구되는 코리올리 효과에 대하여 살펴보고자 한다. 코리홀리 효과는 이동체의 운동을 회전하는 좌표계에서 관측할 경우 발생하는 특이한 현상에 해당되며 관성센서를 다루기 위한 준비 과정에서 많은 입문자들이 어려움을 가지는 부분으로 이해된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.493-495
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• 2015

PDR은 일반적으로 IMU센서로 부터의 가속도와 각속도를 측정하여 보행자의 위치를 추적하는 시스템이다. IMU센서로부터 측정된 가속도와 각속도 값은 센서를 기준으로 하기 때문에 보행자가 인지하는 고정 좌표계와는 차이가 있다. 이를 해결하기 위해 회전행렬을 사용하며 이후 계속해서 측정되는 각속도를 통해 회전행렬을 업데이트 한다. 업데이트된 회전행렬을 통해 좌표계를 환산하고 환산된 좌표계의 가속도 값으로부터 보행자는 고정좌표계 기준으로 위치 추적이 가능하다. 하지만 회전행렬을 업데이트 하는 과정에서 센서의 세 축이 이상적으로 수직이 아니라면 업데이트 과정에서 각속도의 오차가 누적되고 이는 좌표계를 환산에 영향을 끼쳐 위치 및 속도 추적 정확성을 낮춘다. 물리적인 Bias가 PDR 시스템에 누적오차를 발생시킨다. 이에 제안하는 센서 축 편향 보정 알고리즘은 IMU 센서의 물리적 축 오차를 보정해주어 더 정확한 위치 추적을 가능하게 한다. 또한 Matlab을 통해 데이터를 분석하고 알고리즘의 필요성을 보인다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.9-17
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• 2001

GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.1
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• pp.21-29
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• 2003

The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.