• International Journal of Aeronautical and Space Sciences
• /
• v.17 no.4
• /
• pp.579-592
• /
• 2016

CNUSAIL-1, to be launched into low-earth orbit, is a cubesat-class satellite equipped with a $2m{\times}2m$ solar sail. One of CNUSAIL's missions is to deploy its solar sail system, thereby deorbiting the satellite, at the end of the satellite's life. This paper presents the design results of the attitude control system for CNUSAIL-1, which maintains the normal vector of the sail by a 3-axis active attitude stabilization approach. The normal vector can be aligned in two orientations: i) along the anti-nadir direction, which minimizes the aerodynamic drag during the nadir-pointing mode, or ii) along the satellite velocity vector, which maximizes the drag during the deorbiting mode. The attitude control system also includes a B-dot controller for detumbling and an eigen-axis maneuver algorithm. The actuators for the attitude control are magnetic torquers and reaction wheels. The feasibility and performance of the design are verified in high-fidelity nonlinear simulations.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.632-634
• /
• 2005

In this paper, The Frenet-Serret formula of classical geometric curve theory with the concept of a missile pointing velocity vector are used to analyze and design a missile guidance law. The capture capability of this guidance law is qualitatively studied by comparing the rotations of the velocity vectors of missile and target relative to the line of sight vector. when fuzzy Table look-up theory applied in target-missile distance & angle displacement, this research. It's performance is better then classical research.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.1099-1100
• /
• 2008

In this paper, we would like to introduce a simple and low cost wired pointing device by using a electromagnetic induction. A number of patents of Wacom describe electronic drawing devices or styluses. The movement of the stylus over a tablet is traced electronically and used applied to a resonant circuit in the stylus. Electromagnetic radiation emitted by the resonant circuit is detected by a sensing mechanism and location processing is used to locate the stylus. In this research, difference coil principle is used to detect the emitted radiation of the resonant circuit in the pen. This detection device shows good performance to detect the location of the pen on the tablet.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.110-114
• /
• 1995

This paper presents the on-board attitude determination algorithm for LEO (Low Earth Orbit) three-axis stabilized spacecraft. Two advanced star trackers and a three-axis Inertial Reference Unit (IRU) are assumed to be attitude sensors. The gyro in the IRU provides a direct measurement of the attitude rates. However, the attitude estimation error increases with time due to the gyro drift and noise. An update filter with measurements of star trackers and/or sun sensor is designed to update these gyro drift bias and to compensate the attitude error. Kalman Filter is adapted for the on-board update filter algorithm. Simulation results will be presented to investigate the attitude pointing performance.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.3
• /
• pp.50-57
• /
• 2008

A telemetry ground station has a highly directional, parabolic tracking antenna to receive a weak telemetry signal from a target at a distance. The tracking antenna with narrow beam-width normally uses the auto-track method for the target tracking. This paper presents several issues in the auto-track method and introduces a new tracking method using Self-Slaving technique. Self-Slaving means that the tracking antenna is slaved to not data measured by RADAR but GPS/INS informations received by the telemetry system for pointing. The Self-Slaving method shows good performance in comparison with auto-track method.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.4
• /
• pp.878-884
• /
• 2013

Recent C ++ developers take advantage of the many advantages in memory management in the development of reference counting smart pointer. However, these have a problem more than the normal pointer. In this paper, we not only complement these by reference counting smart pointer which pointing a large dynamic object to perform a delete operation to improve performance by creating a thread for the delete operation but also Generalize all data types, we propose a convenient way to operate.

• Journal of Astronomy and Space Sciences
• /
• v.17 no.2
• /
• pp.309-316
• /
• 2000

KOMPSAT-2 will carry MSC(Multi-Spectral Camera) which provides 1m resolution panchromatic and 4m resolution multi-spectral images at the altitude of 685km sun-synchronous mission orbit. The mission operation of KOMSPAT-2 is to provide the earth observation using MSC with nadir pointing. KOMPSAT-2 will also have the capability of roll/pitch tilt maneuver using reaction wheel of satellite as required. In order to protect MSC from thermal distortion as well as direct sunlight, MSC shall be operated within the constraint of sun incidence angle. It is expected that the sunlight will not violate the constraint of sun incidence angle for normal mission operations without roll/pitch maneuver. However, during roll/pitch tilt operations, optical module of MSC may be damaged by the sunlight. This study analyzed sun incidence angle of payload using KOMPSAT-2 AOCS (Attitude and Orbit Control Subsystem) Design and Performance Analysis Soft ware for KOMPSAT-2 normal mission operations.

• ETRI Journal
• /
• v.30 no.4
• /
• pp.621-623
• /
• 2008

We propose a novel input pointing device called the multimodal mouse (MM) which uses two modalities: face recognition and speech recognition. From an analysis of Microsoft Office workloads, we find that 80% of Microsoft Office Specialist test tasks are compound tasks using both the keyboard and the mouse together. When we use the optical mouse (OM), operation is quick, but it requires a hand exchange delay between the keyboard and the mouse. This takes up a significant amount of the total execution time. The MM operates more slowly than the OM, but it does not consume any hand exchange time. As a result, the MM shows better performance than the OM in many cases.

• Ocean Systems Engineering
• /
• v.7 no.4
• /
• pp.319-328
• /
• 2017

Higher prediction efficacy is a very challenging task in any field of engineering. Due to global warming, there is a considerable increase in the global sea level. Through this work, an attempt has been made to find the sea level variability due to climate change impact at Haldia Port, India. Different statistical downscaling techniques are available and through this paper authors are intending to compare and illustrate the performances of three regression models. The models: Wavelet Neural Network (WNN), Minimax Probability Machine Regression (MPMR), Feed-Forward Neural Network (FFNN) are used for projecting the sea level variability due to climate change at Haldia Port, India. Model performance indices like PI, RMSE, NSE, MAPE, RSR etc were evaluated to get a clear picture on the model accuracy. All the indices are pointing towards the outperformance of WNN in projecting the sea level variability. The findings suggest a strong recommendation for ensembled models especially wavelet decomposed neural network to improve projecting efficiency in any time series modeling.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.5
• /
• pp.35-41
• /
• 1998

This paper presents a decoupling controller of the missile seeker scan loop with a spin-stabilized platform. A precise seeker motion with respect to the scan command is essential for the higher acquisition probability of the target. As the seeker scan loop is a deeply cross-coupled two input two output system, an accurate pointing or scanning for each axis to the target is very difficult, even though provided with the help of a high performance controller. When a decoupling control is applied to the seeker scan loop, the cross-coupling between two axes can be reduced to a remarkable amount. As a low order of controller is required for the real time operation, a PI controller with decoupling filter is suggested and compared with other controllers. A linearized dynamic model of seeker scan loop is used and validated through the comparison of experimental results of step responses.