• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.45-54
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• 2006

General unmaned airship, in use of aviation photography, needs both airship -controller and camera-controller who work together in harmony. In oder to reduce this manpower and get the good Geographical Information Systems(GIS) data, it is necessary to use a autopilot controller which guides a exact path lines. This paper presents the autopilot control law base on classical PID control. Moreover, this paper shows the result of flight test, the procedure of gain tuning and LOS guidance algorism that is reduce a tracking error.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.643-647
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• 1990

Gunner primary sight(GPS) stabilization system lays line of sight(LOS) to find out a target and transmits informations to the fire control system (FCS). In a moving vehicle, accuracy of LOS and FCS depends on the design of GPS and servomechanism system. The heavy vibration of vehicle on the severe off-road environment degenerates the stabilization capability of GPS. In this study, to stabilize of elevation for GPS using the variable structure control, we derived the dynamic equation of GPS system and designed the variable structure controller. Computer simulation results fulfilled the static and dynamic stability of GPS using the variable structure control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.877-878
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.225-226
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• 2012

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.703-710
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• 2014

An Image-Based Target Tracker maintains LOS(Line Of Sight) to a target by controlling azimuth and elevation gimbals of an ISS(Inertially Stabilized System). Its controller produces the gimbals commands of the ISS using tracking errors provided by an image tracker. The control performance of the target tracker with PI controller generally used for tracking controller is limited because of bandwidth limitation by time delay yielded by image capture and processing of the image tracker. In this paper, tracking controller using target states estimator is proposed which can enhance the tracking performance under the highly dynamic maneuvering conditions of the ISS and the target. Simulation results show that the proposed method can improve the tracking performance than that with only PI controller.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.842-844
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• 1993

We present a F.L.C. (Fuzzy Logic Controller) to control of the oscillation frequency of a V.C.X.O. (Voltage Controled Crystal Oscillator). This F.C.X.O. maintains stable its oscillation frequency inside a range of 1 ppm (one part per millon), with temperature between -55$^{\circ}C$ to＋75$^{\circ}C$.

• Journal of Advanced Research in Ocean Engineering
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• v.2 no.1
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• pp.40-47
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• 2016

This paper describes the design and performance of a hovering AUV constructed at KMOU (Korea Maritime and Ocean University). Before the field test, we analyzed the dynamic performance of the AUV using a simulation program made by Matlab & Simulink. Also, a PID controller was designed to control the thrusters. Using 4 thrusters (2 vertical and 2 horizontal), the AUV could be controlled using dynamic motion with 4-DOF. A simulation and field test were conducted with way-point tracking, maintaining the desired depth. To perform way-point tracking, the AUV can be fine-tuned to the desired heading angle through the LOS (Line Of Sight) method. This paper shows the results of simulation and field tests.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.1
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• pp.1-7
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• 2009

As designing PID control on aircraft, we consider a gain scheduling on altitude and velocity. If pitot tube is not installed in the unpowered air vehicle, the control performance is reduced by the difference between ground speed and air speed with a wind considered. In this paper, a simple guidance controller (LOS: Line of Sight) and the wind estimator using Kalman filter are designed. And we minimize the wind effect through the estimator. Finally, we perform the 6-DOF nonlinear simulation with the wind model to verify the performance of the controller with the wind estimator.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.322-324
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• 2007

In this paper, an eye-in-hand visual servoing strategy for keeping feature points within the FOV(field-of-view) is proposed. We first specify the FOV constraint which must be satisfied to keep the feature points within the FOV. It is expressed as the inequality relationship between (i) the LOS(jine-of-sight) angles of the center of the feature points from the optical axis of the camera and (ii) the distance between the object and the camera. We then design a nonlinear feedback controller which decouples linearly the translational and rotational control loops. Finally, we show that appropriate choice of the controller gains assures to satisfy the FOV constraint. The main advantage of our approach over the previous ones is that the trajectory of the camera is smooth and circular-like. Furthermore, ours can be applied to the large camera displacement problem.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.614-619
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• 2004

The line-of-sight (LOS) stabilization system is a precision electro-mechanical gimbals assembly for rejecting vibration to isolate the load from its environment and point toward the target in a desired direction. This paper describes the design of gimbals system to reject the disturbance and to improve stabilization. To generate movement commands for the actuators in the stabilization system, the control system uses a sensor of angular rotation. The controller is a DSP with transducer and actuator interfaces. Unknown parameters of the gimbals are estimated using the signal compression method. The cross-correlation coefficient between the impulse response from the assumed model and the one from model of the gimbals is used to obtain the better estimation. And SMCPE (sliding mode control with perturbation estimation) is used to control the gimbals. SMCPE provides robustness of the control against the modeling deficiencies and unknown disturbances. In order to compare the performance of SMCPE with the classical SMC, a sample test result is presented.