• Journal of The Korean Association of Information Education
• /
• v.2 no.2
• /
• pp.252-259
• /
• 1998

Vehicle navigation systems employ a certain route planning algorithm that provides the shortest path between the starting point and the destination point. The performance of a given route planning algorithm is measured through the degree of optimal route selection and the time cost to complete searching an optimal path. In this paper, various route planning algorithms are evaluated through computer simulation based on a real digital map database. Among those algorithms evaluated in this paper, the Modified Bi-directional A${\ast}$ algorithm is found to be the best algorithm for use in vehicle navigation systems.

• Journal of Satellite, Information and Communications
• /
• v.7 no.2
• /
• pp.104-109
• /
• 2012

Currently, GPS(Global Positioning System) is used to find user location information. However, in some cases, especially in urban environments, we receive unreliable location information deu to multipath fading. In order to resolve this problem, we propose a closely coupled positioning technique where GPS signal is combined with QZSS signal. Also we proposed and analyze a combining algorithm of GNSS and Wi-Fi signals to get closely coupled location information by referring AP information. Finally, this paper proposes a combined GPS/QZSS/Wi-Fi navigation algorithm to improve navigation performance, and it is verified by testing of car deriving according to availability and accuracy standard.

• 한국항공운항학회:학술대회논문집
• /
• 2004.11a
• /
• pp.295-301
• /
• 2004

• Journal of the Korea Society for Simulation
• /
• v.24 no.4
• /
• pp.43-49
• /
• 2015

Maximum lock-on distance in tactical guidance missile using seeker image is estimated by seeker's FOV, resolution and performance of tracking algorithm. In case, a missile is launched beyond the maximum lock-on distance, the missile is guided by INS pure navigation until it enters the lock-on possible zone. However, the probability of a target's existence within seekers images decreases as flight time goes by. Therefore, it is crucial to determine the distance that satisfies a certain target existence probability (TEP) and the maximum lock-on distance in order for an operator to take over the navigation role between two distances. In this paper, simulation which can analyse TEP in tactical guided missile seeker image is designed.

• Journal of Advanced Navigation Technology
• /
• v.23 no.3
• /
• pp.221-227
• /
• 2019

In this paper, interacting multiple model (IMM) filter was designed that guarantees a stable navigation performance even in the unstable satellite navigation position. In order to design IMM filter in INS / GPS integrated navigation system, sub filter of the IMM filter is defined as Kalman filter. In the IMM filter configuration, two subfilters are determined. Each Kalman filter defines the six-teenth state composed of position, velocity, attitude, and sensor error from the INS error equation and the states additionally derived in case of the coloured measurement noise. In order to verify the performance of the proposed filter, we compared the performance how the filter works in the presence of arbitrary error in GPS navigation solution. The Monte Carlo simulation was performed 100 times and the results were compared with the root mean square(RMS). The results show that the proposed method is stable against errors and show fast convergence.

• Journal of Satellite, Information and Communications
• /
• v.2 no.1
• /
• pp.41-47
• /
• 2007

Software GNSS digitized IF signal simulator is being developed by ETRI as a part of development of software-based GNSS Test & evaluation Facility which will provide test and evaluation environment for various software level application and navigation algorithm in GNSS. Software GNSS IF signal simulator will provide digitized GNSS signal including GPS and Galileo. The requirement analysis and conceptual design for the Software GNSS IF signal simulator is presented in this paper.

• Journal of Advanced Navigation Technology
• /
• v.24 no.1
• /
• pp.16-27
• /
• 2020

This paper investigates the applicability of optical flow information for unmanned aerial vehicle (UAV) navigation under environments where global navigation satellite system (GNSS) is unavailable. Since the optical flow information is one of important measurements to estimate horizontal velocity and position, accuracy of the optical flow information must be guaranteed. So a navigation algorithm, which can estimate and cancel biases that the optical flow information may have, is suggested to improve the estimation performance. In order to apply and verify the proposed algorithm, an integrated simulation environment is built by designing a guidance, navigation, and control (GNC) system. Numerical simulations are implemented to analyze the navigation performance using this environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.11a
• /
• pp.166-168
• /
• 2023

기존 eLoran 수신기는 보정기준국(인천·평택항 반경 30km 이내에서만 이용 가능하며 ASF 맵보정 정보를 저장하는데 한계가 있음. 자체 오차정보를 보정하는 기능을 가진 eLoran/GPS 통합수신기의 알고리즘 및 성능 분석을 통해 더 넓은 해역에서 eLoran 서비스를 백업항법시스템으로 이용하기 위한 기반 마련

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.5
• /
• pp.190-196
• /
• 2015

In this paper, we propose multiple location error compensation algorithm for GPS/INS fusion using kalman filter and introduce the way to reduce location error in 9-axis navigation devices for implementing inertial navigation technique. When evaluating location, there is an increase of location error. So navigation systems need robust algorithms to compensate location error in GPS/INS fusion. In order to improve robustness of 9-axis inertial sensor(mpu-9150) over its disturbance, we used tilt compensation method using compensation algorithm of acceleration sensor and Yaw angle compensation to have exact azimuth information of the object. And it shows improved location result using these methods combined with kalman filter.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.48 no.10
• /
• pp.783-789
• /
• 2020

This paper proposes a new method for vision-based navigation using semantically segmented aerial images. Vision-based navigation can reinforce the vulnerability of the GPS/INS integrated navigation system. However, due to the visual and temporal difference between the aerial image and the database image, the existing image matching algorithms have difficulties being applied to aerial navigation problems. For this reason, this paper proposes a suitable matching method for the flight composed of navigational feature extraction through semantic segmentation followed by template matching. The proposed method shows excellent performance in simulation and even flight situations.