• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.564-566
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• 1992

It is tragic that the Korean Airline Boing 747, KE007, wandered hundreds of miles off course into Soviet airspace and was shot down on September 1, 1983. The exact cuases are not known yet. Thus, speculation centers on human error or faulty procedure of three Litton LTN-72R inertial navigation systems(INS) with which the KAL KE007 was equipped. The inertial platform must be aligned before the INS can be used as a precision inertial navigation system. This analysis checks a possibility that the navigation errors are caused by a wrong INS alignment procedure assuming it is done at Anchorage. Possible causes for the navigational position error, such as alignment errors and gyro drift errors, are analyzed through inertial navigation system error prapagation simulations. A set of misalignment angle is estimated to determine what degree of alignment errors are required to cause the navigation error assuming that the accident is caused by the INS misalignment.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.51-57
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• 2012

In this paper, design of an error model is presented in which the bias characteristic of the MEMS IMU is taken into consideration for performance enhancement of the MEMS IMU-based GPS/INS integrated navigation system. The drift bias of the MEMS IMU is modeled as a 1st-order Gauss-Markov (GM) process, and the autocorrelation function is obtained from the collected IMU data, and the correlation time is estimated from this. Prior to obtaining the autocorrelation function, the noise of IMU data is eliminated based on wavelet. As a result of simulation, it is represented that the parameters of error model can be estimated correctly only when a proper denoising is performed according to dynamic behavior of drift bias, and that the integrated navigation system based on error model, in which the drift bias is considered, provides more correct navigation performance compared to the integrated navigation system based on error model in which the drift bias is not considered.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.95-101
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• 2013

The paper investigates the geometric effect of landmarks to the navigation error in the landmark based 3D vision navigation and introduces the INS/Vision integrated navigation system considering its effect. The integrated system uses the vision navigation results taking into account the dilution of precision for landmark geometry. Also, the integrated system helps the vision navigation to consider it. An indirect filter with feedback structure is designed, in which the position and the attitude errors are measurements of the filter. Performance of the integrated system is evaluated through the computer simulations. Simulation results show that the proposed algorithm works well and that better performance can be expected when the error characteristics of vision navigation are considered.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.2
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• pp.56-69
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• 2006

For a relatively small country like Korea, a radionavigation system using airships can be considered, which is to provide the navigation service utilizing the stratospheric airships that are deployed in the stratosphere at the altitude of around 20-23km, and which is an independent or a back-up radionavigation system other than current GPS or GLONASS. In this paper, a feasibility study on the constellation of stratospheric airships for the navigation system has been performed. A measure of a geometrical condition between a receiver and navigation transmitters. called the DOP (Dilution of Precision), determines the resulting positioning error of the navigation system, if the error of range measurement is predictable. Therefore, with assumption that the range measurement error of the stratospheric airship navigation system is quite similar to GPS. the several DOP values have been used to evaluate the performance of the navigation system with comparing with the DOP values of GPS as the reference values. To provide the position information of the navigation transmitters to users, a receiver cluster system fixed on the ground, called an IGPS (inverted GPS), is proposed, and the error is also evaluated using the DOP values. Five areas around five major cities in South Korea have been selected, and then by numerical simulations the DOP values are compared those of GPS to assess the performance of the proposed navigation system using stratospheric airships. The possible frequency bands have been proposed. and then link budget of the navigation transmitter has been analyzed for the proposed navigation system.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.5
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• pp.584-591
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• 2014

This paper presents a novel aided navigation method for AUV (Autonomous Underwater Vehicles). The navigation system for AUV includes several sensors such as IMU (Inertial Measurement Unit), DVL (Doppler Velocity Log) and depth sensor. In general, the $13^{th}$ order INS error model, which includes depth error, velocity error, attitude error, and the accelerometer and gyroscope biases as state variables is used with measurements from DVL and depth sensors. However, the model may degrade the estimation performance of the heading state. Therefore, the $11^{th}$ INS error model is proposed. Its validity is verified by using a degree of observability and analyzing steady state error. The performance of the proposed model is shown by the computer simulation. The results show that the performance of the reduced $11^{th}$ order error model is better than that of the conventional $13^{th}$ order error model.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.445-452
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• 2024

This paper analyzes the navigation error for each rotational motion in order to design an optimal rotation sequence, which is a key technology in the rotational inertial navigation. Rotational inertial navigation system is designed to cancel out navigation errors caused by inertial sensor errors by periodically rotating the inertial measurement unit. A properly sequenced rotational motion cancels out the maximum amount of navigation error and is known as an optimal rotation sequence. To design such an optimal turning procedure, this paper identifies the feasible rotational motions that can be implemented in a rotational inertial navigation system and analyzes the navigation error introduced by each rotational motion. In addition, by analyzing the characteristics of the navigation error generated during a rotation sequence in combination, this paper presents the conditions for designing an optimal rotation sequence.

• Journal of Navigation and Port Research
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• v.29 no.7
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• pp.611-614
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• 2005

This paper is to develop the position error equation of in the free-gyro positioning system by using two free gyros. First, the determination of a position is analyzed on the ellipsoid of the Earth and the type of the errors is defined Finally the position error equation is introduced and developed, based on the definition of the type of errors which may be involved in the FPS.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.3
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• pp.141-150
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• 2015

In this study, a Global Navigation Satellite System (GNSS) / Inertial Navigation System (INS) / odometer / barometer integrated navigation system that uses a commercial navigation device including Micro Electro Mechanical Systems (MEMS) accelerometer and gyroscope in addition to GNSS, odometer information obtained from a vehicle, and a separate MEMS barometer sensor was implemented, and the performance was verified. In the case of GNSS and GNSS/INS integrated navigation system that are generally used in a navigation device, the performance would deteriorate in areas where GNSS signals are not available. Therefore, an integrated navigation system that calculates a better navigation solution in areas where GNSS signals are not available compared to general GNSS/INS by correcting the velocity error of GNSS/INS using an odometer and by correcting the cumulative altitude error of GNSS/INS using a barometer was suggested. To verify the performance of the navigation system, a commercial navigation device (Softman, Hyundai Mnsoft, http://www.hyundai-mnsoft.com) and a barometer sensor (ST Company) were installed at a vehicle, and an actual driving test was performed. To examine the performance of the algorithm, the navigation solutions of general GNSS/INS and the GNSS/INS/odometer/barometer integrated navigation system were compared in an area where GNSS signals are not available. As a result, a navigation solution that has a smaller position error than that of GNSS/INS could be obtained in the area where GNSS signals are not available.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1104-1110
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• 2014

This paper investigates geometric effect of landmarks on three-dimensional navigation error in landmark-based vision navigation systems. Dilution of precision is derived for landmark measurement error on the focal plane of the camera and separately expressed in position DOP and attitude DOP. Values of DOP are observed for various configurations of landmarks.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.302-308
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• 2014

In this paper, a detailed investigation of the random vibration test is presented for strapdown inertial navigation systems (INS). The effect of the random vibration test has been studied from the point of view of navigation performance. The role of distribution functions and RMS value is represented to determine a feasible method to reject or reduce vibration related error in position and velocity estimation in inertial navigation. According to a survey conducted by the authors, this is the first time that the effect of the distribution function in vibration related error has been investigated in random vibration testing of INS. Recorded data of navigation grade INS is used in offline static navigation to examine the effect of different characteristics of random vibration tests on navigation error.