• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.182-188
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• 1994

In recent years, navigational and fisheries instruments are rapidly advancing. Especially data processing. data transferring and data interchange throughout the digital signals has been in high progress. Even though the ship's heading is also provided by a gyro-compass, an electro-magnetic compass studying by us currently is easy to issue adequate data to instruments requiring the information for the ship's heading. especially in small fishing boats. As the main element of the electro-magnetic compass is a three-axis magnetic sensors, the developing of the high performance sensor is in highly necessity in the beginning. This paper describes on the development of electro-magnetic compass of three-axis fixed type by using three-axis detection new type magnetic sensor without gimbals. even though usual electro-magnetic compass have to need necessarily a gimbal system in order to keep horizontal condition of the compass.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.35-40
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• 2004

The high-speed wind tunnel test of rocket model was performed to investigate the effect of skirt configuration on aerodynamic load characteristics of nozzle. Test parameters were the length and diffusing angle of skirt. Test results showed that the gimbals actuator power could be reduced to 1/10 of that without skirt. The normalized test result was proposed to be used as database for skirt design.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.110-112
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• 2003

The researchers, who seek geological and environmental information, depend on the remote sensing and aerial photographic datum from various commercial satellites and aircraft. However, the adverse weather conditions and the expensive equipment can restrict that the researcher can collect their data anywhere and any time. To allow for better flexibility, we have developed a compact, a multispectral automatic Aerial photographic system. This system's Multi-spectral camera can catch the visible (RGB) and infrared (NIR) bands (3032${\ast}$2008 pixel) image. Our system consists of a thermal infrared camera and automatic balance control, and it managed and controlled by a palm-top computer. And it includes a camera gimbals system, GPS receiver, weather sensor and etc. As a result, we have successfully tested its ability to acquire aerial photography, weather data, as well as GPS data, making it a very flexible tool for environmental data monitoring.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.337-340
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• 2004

Stabilizing systems with Gyroscope are extensively used in various tracking devices for attaining the system's objective. Because of putting performance first in importance of system and focusing on specification of parts, designers are sometimes passing over the dynamic characteristics of system in vibrating condition. In this paper, we were dealing with unstable stabilizing control due to coincidence of stabilization platform natural frequency and that of Gyroscope used for sensing rate. For solving this problem, statics and dynamic test of silicon rubber with 3 different hardness were performed and similar stabilizing system was adopted to prove reasonability of rubber choice and static pre-strain.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.615-618
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• 2009

2 axis Pan-tilt had been developed and utilize by vessel for the purpose of motion characteristic measurement. Besides, it also use to analysis structural design and fabrication. Test procedure had been created to produce most optimal design and to show the Nano Driving precision result performance.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.18-28
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• 2014

We assume that two control moment gyros are installed for space qualification in a satellite with four reaction wheels, and study the high agile maneuver method. Using high torque control moment gyros, we reduce the satellite's attitude error. After that, we activate reaction wheels to control remaining attitude error. This proposed method can avoid singularity problem of control moment gyros, and do not require gimbals' angle to calculate torque command. Through numerical simulations, we show that our method's agile performance is similar to previous method and reduce the reaction wheels' required momentum.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.497-506
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• 1991

In this paper, a new construction for training simulator of R/C helicopter based on two types of servo controller is proposed. Two modified algorithms (algorithm I and II) for servo controller design are presented. Algorithm I is developed by adopting Davison's method in the case that the expressions for the homogeneous differential equations of reference input and disturbance are different types, and algorithm II is done by considering error weighting function for the servo controller of algorithm I . The linear fractional transformation method is incorporated in both design methods in order to assign the closed loop poles of the servo system in a specified region. The helicopter simulator is composed by the gimbals with two freedom of rolling and pitching. The reliability and validity for the design methods of the proposed servo controller are investigated through the practical experiment for the simulator by using 16bits micro-computer with A/D and D/A converters. It can be observered from the experimental results that the proposed servo controller is applicable to practical plants since the simulator is robust for the arbitrary disturbance and it follows to the given reference input without significant steady state error.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1146-1152
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• 2003

Satellite television receiving antenna is required for watching TV on the vehicles, ship and car. Recently TV is not only facility as getting information but one of utility in our life. In Korea, already on the service multi-channel satellite TV using excellent visibility and sound, and there are many users using now by fixing antenna. On this thesis, developed ship's satellite TV receiving antenna, the azimuth controlling is adopted azimuth information using gyro sensor and differential of receiving signal strength algorithm, and elevation controlling used gimbals. The result of this research is successfully implemented Korean satellite tracking antenna as performance until ${\pm}$30 degree roll and pitch of ship motion.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.813-820
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• 2014

This paper presents design and performance validation of a method for motion compensation using fast steering mirror. First of all, the schematics of the Electro Optical/Infra-Red (EO/IR) and step-stare image gathering system for an aerial reconnaissance are introduced. Because of the steering mirror with low inertia so called Back scan mechanism (BSM), the fast step-stare image gathering technique that is required for taking a high-definition still image will be realized. After then, the BSM hardware includes motors and feedback sensors are introduced. Also, the motion profile for BSM will be designed to compensate roll scan motion of the gimbals. At the end of this paper, designed profile and tracking performance of the EO/IR system with BSM will be validated through experiments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.10
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• pp.951-959
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• 2011

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.