• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.971-976
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• 1996

A flexible pointing system mounted on top of a vehicle suffers from performance degradation due to bending vibrations as the vehicle runs on a bump course. In order to improve the pointing performance, the pointing structure's vibrations should be suppressed. In this paper, a nonlinear controller is designed to control the tip position of the pointing system while actively suppressing the vibrations. To cope with high order dynamics and nonlinearities of the plant and hydraulic actuating system, a two-stage sliding mode controller is devised. The desired actuating pressure is obtained in the first stage and then the in put current In the hydraulic servo system is computed to generate the pressure. The simulation results show the effectiveness of this scheme and improvements in pointing accuracy.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제10권2호
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• pp.67-80
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• 2006

본 논문에서는 스테레오 비전을 이용하여 기존의 포인팅 디바이스인 마우스를 대신할 새로운 포인팅 디바이스 방법을 제안 한다. 제안한 방법은 기존의 인식 장비들이 가진 마커에 의한 움직임 제약과 고가 장비의 단점을 극복하기 위해 컴퓨터 비전을 이용한다. 즉, 사람이 시각을 통해 정보를 인식하는 것과 동일하게 컴퓨터의 영상 정보를 이용하여 실시간으로 영상내의 컬러 영역의 분할을 통해 물체의 위치를 추적 및 정합하고 이의 위치를 스테레오 기하학 정보로부터 계산하여 포인팅 동작을 수행한다.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.498-509
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• 2015

The existing mobile antenna networks in the military use have been operated by the manual pointing between two antennas. The work presented here describes the study of ATPC(Automatic Tracking and Pointing Control) system between facing antennas and the related tracking and pointing performances. This system is able to automatically track the maximum RSSI(Received Signal Strength Indication) value from the source's RF(Radio Frequency) signal and then control for maintaining the LOS(Line of Sight) between two antennas. The system has three major units; the driving unit consisting of motors, harmonic drives and encoders, the sensor unit with a GPS(Global Positioning System) and AHRS(Attitude and Heading Reference System) and the control unit regulating all the tracking and pointing events. By using PI(Proportional and Integral) controller, this system is able to properly track and point the other antenna under the external disturbance like the wind load. Both the simulation and the experimental works have been successively carried out to prove the performances of the system.

• 한국군사과학기술학회지
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• 제12권6호
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• pp.750-759
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• 2009

FLIR(Forward Looking Infrared) geo-pointing is a function that helps pilots to see a target within the field of view under all coordinates and attitudes of helicopter. Geo-pointing controls FLIR LOS(line of sight) toward known target coordinates by using azimuth and elevation angles calculated from several information such as helicopter coordinates and attitudes, a FLIR position from a GPS antenna, and target coordinates. Geo-pointing performance has been tested and evaluated on the ground to save flight test costs and ensure flight safety. In this paper, design and implementation of a geo-pointing system is described with the results of performance test conducted on the ground test system.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2006년도 추계학술발표대회
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• pp.281-284
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• 2006

본 논문은 지체장애인들의 컴퓨터 접근성을 향상시키기 위해서 Head Pointing System을 기반으로한 키보드 대체 방법을 제안한다. 먼저 컴퓨터의 접근성을 돕기위해 현재 사용되고있는 Head Pointing System에는 어떤 기능을 대체하고 있는지 간략하게 살펴보고, 본 논문에서 제안하는 방법이 이전에 사용되었던 Head Pointing System, On-Screen Keyboard를 함께 사용하여 문자를 입력하는 방식에 비해 어떤 이점이 있는 확인한다. 또한, Quikwriting 방식을 사용하여 사용자에게 단순하고 직관적인 제스쳐를 요구하도록하여 입력에 대한 부담을 낮추고, 사용자 개인의 제스쳐 특성에 따라 문자를 입력할 수 있도록 하기위해 신경망 알고리즘을 사용하였고 이를통해 Head Pointing System기반 문자입력 방법이 유용함을 확인할 수 있었다.

• 한국정밀공학회지
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• 제21권5호
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• pp.55-63
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• 2004

This paper presents neural network based controller using the feedback error loaming technique for a heavy load pointing system. Also the mathematical model was developed to analyze heavy load pointing system. The control scheme consists of a feedforward neural network controller and a fixed-gain feedback controller. This neural network controller is trained so as to make the output of the feedback controller zero. The proposed controller is compared with the conventional PI controller through simulations, and the results show that the pointing accuracy of the proposed control system are improved against the disturbance induced by vehicle running on the bump course.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.290-293
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• 2009

In this paper, we propose a method to estimate pointing region in real-world from images of cameras. In general, arm-pointing gesture encodes a direction which extends from user's fingertip to target point. In the proposed work, we assume that the pointing ray can be approximated to a straight line which passes through user's face and fingertip. Therefore, the proposed method extracts two end points for the estimation of pointing direction; one from the user's face and another from the user's fingertip region. Then, the pointing direction and its target region are estimated based on the 2D-3D projective mapping between camera images and real-world scene. In order to demonstrate an application of the proposed method, we constructed an ICGS (interactive cinema guiding system) which employs two CCD cameras and a monitor. The accuracy and robustness of the proposed method are also verified on the experimental results of several real video sequences.

• 한국군사과학기술학회지
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• 제4권2호
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• pp.157-178
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• 2001

In this paper, the nonlinear control of high precision pointing stabilization system using feedback-linearization design methodology based on system parameter identification is discussed. Modern nonlinear servomechanism theory is adapted to cope with the hard nonlinearities inherent in the turret system. The mathematical models of electrical turret driving system to develop a high performance control algorithm are derived, and the parameter estimation algorithm identifying the unknown system parameters such as vicious and coulomb frictions, stiffness and inertia is developed. Through computer simulation and experiments, it is shown that pointing and tracking accuracy and stabilization against the wideband stochastic disturbance induced by vehicle running on the bump course are improved. Therefore, it is considered the proposed nonlinear control technique is effective in counteracting the nonlinearities and disturbances.

• 한국군사과학기술학회지
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• 제10권2호
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• pp.12-20
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• 2007

The aiming ability is a key to improve the accuracy performance of the gun pointing system in the ground military vehicle. This paper describes the new detection method of chatter vibration using disturbance acceleration in the pointing structure. In order to analysis the vibration trends of the pointing system occurred while the vehicle driving, acceleration data obtained from vehicle was processed by using data processing algorithm with moving average and Hilbert transform. The specific mode constants of acceleration were obtained from various disturbances. Vehicle velocity, road condition and property of pointing structure were considered as factors which make the change of vibration trend in vehicle dynamics. Finally, back propagation neural networks have been applied to the pattern recognition of the classification of vibration signal in various driving conditions. Results of signal processing were compared with other condition result and analysed.

• 제어로봇시스템학회논문지
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• 제10권9호
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• pp.840-846
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• 2004

In this study, the performance of a heavy load pointing system has been investigated. The PI controller are being widely used in industrial application because of simple, cheap, and excellent performance. However, the requirement for control precision becomes higher and higher, as well as the plants becomes more and more complex. In order to achieve the satisfied control performance, we have to consider the affection of nonlinear factor contained in plant. In this paper, the neural-PI control law have been evaluated. The proposed controller is compared with the existing controllers through simulations, and the results show that the pointing accuracy of the proposed control system is improved against the disturbance induced by vehicle running on the bump course.