• Advances in aircraft and spacecraft science
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• v.7 no.1
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• pp.1-17
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• 2020

In this paper, a new model-based Fault Detection and Diagnosis (FDD) method for an agile supersonic flight vehicle is presented. A nonlinear model, controlled by a classical closed loop controller and proportional navigation guidance in interception scenario, describes the behavior of the vehicle. The proposed FDD method employs the Inertial Navigation System (INS) data and nonlinear dynamic model of the vehicle to inform fins damage to the controller before leading to an undesired performance or mission failure. Broken, burnt, unactuated or not opened control surfaces cause a drastic change in aerodynamic coefficients and consequently in the dynamic model. Therefore, in addition to the changes in the control forces and moments, system dynamics will change too, leading to the failure detection process being encountered with difficulty. To this purpose, an equivalent aerodynamic model is proposed to express the dynamics of the vehicle, and the health of each fin is monitored by the value of a parameter which is estimated using an adaptive robust filter. The proposed method detects and isolates fins damages in a few seconds with good accuracy.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.89-98
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• 1994

Digital road map - which plays an essential role in giving accurate location of the vehicle, optimum route guidance, destination searching, and topographic feature query functions - is the most fundamental element of the vehicle navigation system. Unfortunately, there is not a nation-wide digital map in Korea such as U.S. TIGER fie, that is easily applied to digital road database production. Therefore, producing new digital road map is inevitable in Korea For establishing digital road map for vehicle navigation, this paper puts forth the necessary condition to stabilize the digital road map qualify, and to keep up the compatibility and the economical use. As a result, the standards of coordinate and map accuracy arc presented, and the Items and the structures of database arc decided.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.1
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• pp.77-88
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• 2015

The dynamics of relative motion in a perturbed orbital environment are exploited based on Gauss' and Cowell's variational equations. The inertial coordinate frame and relative coordinate frame (Hill frame) are used, and a linear high fidelity model is developed to describe the relative motion. This model takes into account the primary gravitational and atmospheric drag perturbations. Then, this model is used in the design of a navigation, guidance, and control system of a chaser vehicle to approach towards and to depart from a target vehicle in proximity operations. Relative navigation uses an extended Kalman filter based on this relative model to estimate the relative position/velocity of the chaser vehicle with respect to the target vehicle. This filter uses the range and angle measurements of the target relative to the chaser from a simulated LIDAR system. The corresponding measurement models, process noise matrix, and other filter parameters are provided. Numerical simulations are performed to assess the precision of this model with respect to the full nonlinear model. The analyses include the navigation errors and trajectory dispersions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.145-147
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• 2010

This study is the visually emotional identification lighting for easy to distinguish using 3colors LED on AtoN facility in shore and harbor, which have realized a controller for certainly express the mouth of a harbor by red light and green light of both sides a harbor and for synchronization at a time of right and left or serial sequential the harbor guidance light through synchronizer or timer by GPS. There is expectation effect that is prevent a confusion about distinguish of facility by ship's operator and to beautify a night scene of harbor, which is expressed to emotional identification lighting differ from great many lighting of harbor with variable color lighting the lighthouse body and vertical layer color lighting using LED. The function of AtoN is adapted that guidance light through synchronization or serial sequential lighting and display of harbor safety message by CW lighting, and this system is the power consumption greatly reduce by candle alternated high light LED.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.15-22
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• 2016

The A-SMGCS is a modular system defined in the ICAO manual on advanced surface movement guidance and control systems. Such systems aim to maintain the declared surface movement rate under all weather conditions while maintaining the required level of safety. In this paper, we find out the details and 14 modules'specific features that developing Level IV A-SMGCS in Korea. Also we figure out relation domestic regulations as SMGCS manual & visual aids manual in Korea and research foreign cases such as defined ICAO 9830 manual, EUROCONTROL's project 'EMMA2' document, and FAA advisory circular-150 manual. It will be used as analysis data that can be applied to the undefined A-SMGCS in Korea technical regulation.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.43-49
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• 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 the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.146-156
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• 2018

The ship's chart system was changed from the use of paper chart to the ENC (Electronic Navigational Chart) using ECDIS (Electronic Chart Display and Information System). The introduction of ENC in ships is necessary for ship automation and for the digitalizing of data and integration of information, but unexpected various problems have occurred and are posing a great threat to safe navigation in the transitional period when the new system has been applied to the sea. In this paper, to assess whether ECDIS contributes to the safety of navigation for its intended purposes as new navigation equipment, a usability test of ECDIS was conducted on masters and crew who have used ECDIS on ocean-going vessels. The result was verified with a paired sample T-test, and it was significantly analyzed with the effectiveness of a simplified task; cost efficiency was decreased since ECDIS was used. By analyzing 'MSC.1/Circ.1503 ECDIS - Guidance for good practice', we found that the effects of the maintenance of ECDIS software, operating anomalies identified within ECDIS, differences between raster chart display system (RCDS) and ECDIS, and matters of identification were compounded by the overlapping information on the safety of ships. The anomalies were also grouped according to their characteristics, and we proposed suitable improvements accordingly. The reason for the reduction in efficiency in the usability test was that the problems with ECDIS were intended to be solved only with the careful use of navigational officers who did not have systematic solutions. To solve these problems, the maintenance of software, the improvement of ECDIS anomalies, the reliable ENC issuance including the global oceans, and S-mode development are a priority.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.415-419
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• 2010

Objective : It is usually difficult to perform the neuroendoscopic procedure in patients without hydrocephalus due to difficulties with ventricular cannulation. The purpose of this study was to find out the value of navigation guided neuroendoscopic biopsy in patients with peri- or intraventricular tumors without hydrocephalus. Methods : Six patients with brain tumors without hydrocephalus underwent navigation-guided neuroendoscopic biopsy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by chemotherapy and/or radiotherapy as the first line treatment, or establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy. Results : Under the guidance of navigation, targeted lesion was successfully approached in all patients. Navigational tracking was especially helpful in entering small ventricles and in approaching the third ventricle through narrow foramen Monro. The histopathologic diagnosis was established in all of 6 patients : 2 germinomas, 2 astrocytomas, 1 dysembryoplastic neuroepithelial tumor and 1 pineocytoma. The tumor biopsy sites were pineal gland (n = 2), suprasellar area (n = 2), subcallosal area (n = 1) and thalamus (n = 1). There were no operative complications related to the endoscopic procedure. Conclusion : Endoscopic biopsy or resection of peri- or intraventricular tumors in patients without hydrocephalus is feasible. Image-guided neuroendoscopic procedure improved the accuracy of the endoscopic approach and minimized brain trauma. The absence of ventriculomegaly in patients with brain tumor may not be served as a contraindication to endoscopic tumor biopsy.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.485-492
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• 2021

Vision-based autonomous precision landing technology for UAVs requires precise position estimation and landing guidance technology. Also, for safe landing, it must be designed to determine the safety of the landing point against ground obstacles and to guide the landing only when the safety is ensured. In this paper, we proposes vision-based navigation, and algorithms for determining the safety of landing point to perform autonomous precision landings. To perform vision-based navigation, CNN technology is used to detect landing pad and the detection information is used to derive an integrated navigation solution. In addition, design and apply Kalman filters to improve position estimation performance. In order to determine the safety of the landing point, we perform the obstacle detection and position estimation in the same manner, and estimate the speed of the obstacle using LSM. The collision or not with the obstacle is determined based on the CPA calculated by using the estimated state of the obstacle. Finally, we perform flight test to verify the proposed algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.896-902
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• 2007

This paper proposes a vision-based kinematic control method for mobile robots with camera-on-board. In the previous literature on the control of mobile robots using camera vision information, the forward velocity is set to be a constant, and only the rotational velocity of the robot is controlled. More efficient motion, however, is needed by controlling the forward velocity, depending on the position in the corridor. Thus, both forward and rotational velocities are controlled in the proposed method such that the mobile robots can move faster when the comer of the corridor is far away, and it slows down as it approaches the dead end of the corridor. In this way, the smooth turning motion along the corridor is possible. To this end, visual information using the camera is used to obtain the perspective lines and the distance from the current robot position to the dead end. Then, the vanishing point and the pseudo desired position are obtained, and the forward and rotational velocities are controlled by the LOS(Line Of Sight) guidance law. Both numerical and experimental results are included to demonstrate the validity of the proposed method.