• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.631-638
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• 2018

In this paper, we propose a method to improve the performance by guidance technique and applying it to the precision guided ammunition. The proposed method is a technique designed to reduce the target error of ammunition by reducing the projectile error without analyzing the motion characteristics of the shot. This technique is applied to the moving average filter technique which is widely used as signal processing technique to reduce the fluctuation of the output of the inboard mounting inertial sensor caused by the rotation and the coning motion of the ammunition. In order to compare the performance of the applied technique including the simple 3D guided control technique and the proposed improvement technique. It is confirmed that the application of this technique improves the accuracy of impact of the cannon - launched ammunition with severe environmental conditions and irregular motion characteristics unlike the missile.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.342-351
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• 2010

UAV (Unmanned Aerial Vehicle) have an INS(Inertial Navigation System) equipment and also have an electro-optical Equipment for mission. This paper proposes the vision based attitude estimation algorithm using Kalman Filter and Optical flow for UAV. Optical flow is acquired from the movie of camera which is equipped on UAV and UAV's attitude is measured from optical flow. In this paper, Kalman Filter has been used for the settlement of the low reliability and estimation of UAV's attitude. Algorithm verification was performed through experiments. The experiment has been used rate table and real flight video. Then, this paper shows the verification result of UAV's attitude estimation algorithm. When the rate table was tested, the error was in 2 degree and the tendency was similar with AHRS measurement states. However, on the experiment of real flight movie, maximum yaw error was 21 degree and Maximum pitch error was 7.8 degree.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.68-79
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• 2008

Ground vehicle borne system which is named RoSSAV(Road Safety Survey and Analysis Vehicle) developed in KICT(Korea Institute of Construction Technology) can collect road geometric data. This system therefore is able to evaluate the road safety and analyze road deficient sections using data collected along the roads. The purpose of this study is to extract road geometric data for 3D road modeling in dangerous road section and The system should be able to quickly provide more accurate data. Various sensors(circular laser scanner, GPS, INS, CCD camera and DMI) are installed in moving object and collect road environment data. Finally, We extract 3d road geometry(center, boundary), road facility and slope using integrated multi-sensor data.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.9
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• pp.888-897
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• 2015

A flight capability to take a terrain following flight near the ground is required to reduce the probability that a fighter aircraft can be detected by foe's radar fence in the battlefield. The success rate for mission flight has increased by adopting TFS (Terrain Following System) to enable the modern advanced fighter to fly safely near the ground at the low altitude. This system has applied to the state-of-the-art fighter and bomber, such as B-1, F-111, F-16 E/F and F-15, since the research begins from 1960's. In this paper, the terrain following system and GCAS (Ground Collision Avoidance System) was developed, based on a digital database with UTAS's TERPRROM (TERrain PROfile Matching) equipment. This system calculates the relative location of the aircraft in the terrain database by using the aircraft status information provided by the radar altimeter and the INS (Inertial Navigation System), based on the digital terrain database loaded previously in the DTC (Data Transfer Cartridge), and figures out terrain features around. And, the system is a manual terrain following system which makes a steering command cue refer to flight path marker, on the HUD (Head Up Display), for vertical acceleration essential for terrain following flight and enables a pilot to follow it. The cue is based on the recognized terrain features and TCH (Target Clearance Height) set by a pilot in advance. The developed terrain following system was verified in the real-time pilot evaluation in FA-50 HQS (Handling Quality Simulator) environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.134-141
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• 2013

This paper explores a real-time system implementation to couple tightly StrapDown Inertial Navigation System(SDINS) and Global Positioning System(GPS) mounted on the aircraft. When implementing the SDINS/GPS coupled system in real-time processor, we have to deliberate SDINS's unique characteristics based on the ring laser gyro, and besides, lever-arm, measurements, and error compensation method. The novel modeling method is applied to system the misalignment error term of gyro to estimate the cumulative heading attitude errors while the aircraft banking to turn repeatedly. Captive Flight Test results show that the proposed modeling strategy has good performance.

• Spatial Information Research
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• v.16 no.3
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• pp.373-383
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• 2008

LiDAR, unlike satellite imagery and aerial photographs, which provides irregularly distributed three-dimensional coordinates of ground surface, enables three-dimensional modeling. In this study, urban area was classified based on 3D information collected by LiDAR. Morphological and spatial properties are determined by the ratio of ground and non-ground point that are estimated with the number of ground reflected point data of LiDAR raw data. With this information, the residential and forest area could be classified in terms of height and density of trees. The intensity of the signal is distinguished by a statistical method, Jenk's Natural Break. Vegetative area (high or low density) and non-vegetative area (high or low density) are classified with reflective ratio of ground surface.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.332-340
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• 2011

A missile with a strapdown seeker should properly estimate line-of-sight(LOS) rate using its attitude information and the look angle of the seeker because LOS rate information in an inertial coordinate system, which is used for a proportional navigation(PN) homing guidance, can not be obtained directly. However, an unnecessary feedback loop(Parasite Loop) is formed in the guidance and control loop, and it may cause the guidance performance degradation or even the unstability of the system(Parasite Effect). This paper presents estimation methods for the LOS rate information and effective ways to minimize the parasite effect using Routh-Hurwitz stability criterion. Various numerical simulations are also included to verify the proposed methods.

• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.139-147
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• 1999

In this paper, we present the new angular velocity pick-off method for DTG (dynamically tuned gyroscope) which is widely used in various inertial navigation systems and motion control systems. In case of the external angular velocity input, the proposed scheme can make a smaller tilt-angle rather than that of conventional PI method in the transient and steady state because it has an additional inner rebalance loop with a mathematical model of the real gyroscope. So, without any mechanical redesign of the DTG, its dynamic range can be enlarged by the proposed method. The theoretical analysis and simulation model of DTG with the proposed scheme are given. Finally, the proposed scheme is verified.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.182-190
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• 2005

In the paper, we propose an intelligent automatic parking assist system. To realize an automatic parking, first, the prospective parking position and the location of a vehicle should be recognized. Second, the system should compute a path which introduces the parking position precisely with avoiding any obstacles. Third, the handle should be controlled so that the vehicle moves through the path. To calculate the location of the vehicle and its surroundings, the system applies the camera image method to transforming input images to the plane map. It also uses the inertial navigation method which recognizes the position and the direction of a moving vehicle by using a kinematic model of the vehicle. To generate a path of the vehicle, the simple path method and the Bezier spline method are tested. The divided arc method which generates multiple paths is also tested. We apply a method which makes the system choose the best path with multiple objective functions. We introduce the virtual road method, as a solution for the problem of mechanical time delay, to have the vehicle followed the designated path.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1121-1126
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• 2017

Various studies such as INS(: Inertial Navigation System) are conducting to estimate the position of UAV, because the GPS information of UAV is at risk like the GPS jamming. The position estimation using DoA and RTT are used to apply many radar systems, and that process can be applied in datalink of UAV. The general monopulse feed in UAV datalink is Multi-horn, because of the wide BW(: Band Width) and frequency range. And it needs wide SNR range of tracking because of the limited transmit power of airborne unit. The estimation error of position increase at low SNR, and the DoA is valid in only 3dB beam width but high SNR causes false of mainlobe detection because of large sidelobe. In this paper, We propose the method to achieve higher accuracy of DoA estimation on low SNR and review some idea that able to detect mainlobe.