• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.470-477
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• 2022

EOTS for drones is showing another aspect of market expansion in detection and recognition areas previously occupied by artificial satellites. The two-axis EOTS for drones controls the vibration or disturbance caused by the drone during the mission so that EOTS can accurately recognize the goal. Vibration generated by drones is transmitted to EOTS. Therefore, it is essential to develop a stabilization controller that attenuates vibrations transmitted from drones so that EOTS can maintain the viewing angle. Therefore, it is necessary to standardize drone disturbance and secure the performance of EOTS disturbance attenuation controller optimized for disturbance level through this. In this paper, a method of standardizing drone disturbance applied to EOTS is studied, through which EOTS controller simulation is performed and stabilization controller shape is selected and designed.

• 한국군사과학기술학회지
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• 제5권3호
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• pp.62-76
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• 2002

This paper describes the design of a Coordinates Tracking algorithm for EOTS and its error analysis. EOTS stabilizes the image sensors such as FLIR, CCD TV camera, LRF/LD, and so on, tracks targets automatically, and provides navigation capability for vehicles. The Coordinates Tracking algorithm calculates the azimuth and the elevation angle of EOTS using the inertial navigation system and the attitude sensors of the vehicle, so that LOS designates the target coordinates which is generated by a Radar or an operator. In the error analysis in this paper, the unexpected behaviors of EOTS that is due to the time delay and deadbeat of the digital signals of the vehicle equipments are anticipated and the countermeasures are suggested. This algorithm is verified and the error analysis is confirmed through simulations. The application of this algorithm to EOTS will improve the operational capability by reducing the time which is required to find the target and support especially the flight in a night time flight and the poor weather condition.

• 제어로봇시스템학회논문지
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• 제11권4호
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• pp.369-377
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• 2005

This paper describes the realization of a coordinates tracking algorithm for an EOTS (Electro-Optical Tracking System). The EOTS stabilizes the image sensors, tracks targets automatically, and provides navigation capability for vehicles. The coordinates tracking algorithm calculates the azimuth and the elevation angle of an EOTS using the inertial navigation system and the attitude sensors of the vehicle, so that LOS designates the target coordinates which are generated by a Radar. In the error analysis, the unexpected behaviors of an EOTS due to the time delay and deadbeat of the digital signals of the vehicle equipments are anticipated and the countermeasures are suggested. The application of this algorithm to an EOTS will improve the operational capability by reducing the time which is required to find the target and support flight especially in the night time flight and the poor weather condition.

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.71-81
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• 2022

In order for electro-optical tracking system (EOTS) to have accurate target coordinate, accurate navigation results are required. If an integrated navigation system is configured using an inertial measurement unit (IMU) of EOTS and the vehicle's navigation results, navigation results with high rate can be obtained. Due to the time-delay of the navigation results of the vehicle in the EOTS and scale factor errors of the EOTS IMU in high-speed and high dynamic operation of the vehicle, it is much more difficult to have accurate navigation results. In this paper, an integrated navigation system of EOTS which compensates time-delay and scale factor error is proposed. The proposed integrated navigation system consists of vehicle's navigation system which provides time-delayed navigation results, an EOTS IMU, an inertial navigation system (INS), an augmented Kalman filter and integration Kalman filter. The augmented Kalman filter outputs navigation results, in which the time-delay of the vehicle's navigation results is compensated. The integration Kalman filter estimates position, velocity, attitude error of the EOTS INS and accelerometer bias, accelerometer scale factor error, gyro bias and gyro scale factor error from the difference between the output of the augmented Kalman filter and the navigation result of the EOTS INS. In order to check performance of the proposed integrated navigation system, simulations for output data of a measurement generator and land vehicle experiments were performed. The performance evaluation results show that the proposed integrated navigation system provides more accurate navigation results.

• 한국군사과학기술학회지
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• 제26권1호
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• pp.72-82
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• 2023

The EOTS(Electro Optical Tracking System) must have stabilization performance to provide high-quality images under disturbance environment. In this paper, we present a controller that can minimize the LOS error and has a simple structure. Hence, to evaluate the performance of this controller, analysis in the frequency domain and LOS error measurement are performed. In order to measure the LOS error without a 'rate table' that requires a lot of facility investment, we propose a design method for disturbance model that considers the operating environment of the EOTS. Finally, the performance of the stabilization algorithm is evaluated by the proposed disturbance model.

• 센서학회지
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• 제7권1호
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• pp.23-30
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• 1998

본 논문에서는 전자광학추적기(Electro-Optical Tracking System:EOTS)에 사용되어지는 영상센서의 시간지연으로 인한 영향이 추적루프성능에 주는 영향을 분석하였다. 이에 대한 해결책으로 Smith예측기를 사용함으로서 시간지연을 가지는 시스템의 안정성과 각종성능지수를 향상시킬 수 있음을 모의실험을 통해 보였다. 또한 실제적인 유용성을 확인하기 위하여 최근 개발된 EOTS에 적용하여 그 유용성을 확인하였다.

• 한국항공우주학회지
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• 제37권3호
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• pp.240-247
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• 2009

전자광학추적장치의 공력특성연구를 위한 풍동시험을 수행하였다. 특히 실제 EOTS 작동중 관측부의 회전을 위한 작동기의 충분한 파워 측정을 위한 공력토크 특성을 조사하였다. EOTS의 관측창의 영향을 조사하기 위해 반구와 실린더로 이루어진 단순 모형 실험결과와의 비교를 수행하였다. 단순모형과 EOTS모형의 표면 압력을 비교한 결과를 통해 관측창의 위치에 따라 급격한 압력계수의 변화와 회전 관측부의 토크 특성에 많은 영향을 미치는 것을 발견하였다.

• 제어로봇시스템학회논문지
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• 제19권10호
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• pp.873-878
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• 2013

An EOTS (Electro-Optical Tracking System) provides stabilized images while tracking a moving target. This paper presents a novel concept of driving the outer gimbal first for improving the maneuverability of an EOTS, contrary to the conventional inner gimbal mode. It has the advantages of faster positioning performance and stable operation in Nadir-point. Analysis of frequency responses reveal that the present scheme results in a wider control bandwidth and larger gain margin, compared to those of the previous one. The actual experimental results confirm that the maneuvering is stable although the input command has a large angular acceleration.

• 한국군사과학기술학회지
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• 제16권1호
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• pp.89-94
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• 2013

Electro Otical Tracking System(EOTS) is required for a rapid movement as well as the stabilization of Line-Of-Sight(LOS). In order to achieve these two goals, this paper presents a position and velocity driving profile generation method from the constant acceleration and deceleration profile according to the current state, enabling a fast and smooth trajectory even if the target position changes during the movement of LOS. Simulation and experimental results reveal that the settling time could be reduced significantly by adopting the present position control scheme.

• 항공우주시스템공학회지
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• 제16권4호
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• pp.60-67
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• 2022

일반적인 항공기의 전자광학추적장비(Electro-Optical Tracking System, EOTS)는 EO/IR, 레이저 센서 등의 구성품으로 구성된다. 표적 획득 시 요구되는 표적 좌표는 내부 구성품인 관성측정장비(Inertial Measurement Unit, IMU)에서 측정되는 자세와 가속도 측정값을 이용하여 획득된다. 특히 무장시스템을 운용하는 항공기의 경우, 무장 발사를 위한 표적 좌표를 얼마나 신속하고 정확하게 획득하는가에 따라 무장시스템의 성능이 좌우된다. 무장시스템에서 요구하는 좌표 정확도를 충족하기 위해서는 IMU가 정렬 완료 상태에서 운용되어야 하므로 신속하게 자세와 가속도를 측정하여 IMU 초기 안정화 시간을 단축하여야 한다. IMU의 정렬은 IMU의 자세 오차를 해소하여 초기 자세를 결정하는 과정이며, 항공용 EOTS와 같은 임무장비의 IMU는 항법용 GPS/INS의 속도 정보를 기준으로 하는 속도정합 전달정렬을 수행한다. 본 논문에서는 이러한 속도정합 전달정렬 시간 단축을 위해 항공기와 임무장비의 자세 변화를 통한 전달정렬 성능 개선방안을 제시하였다. 먼저 전달정렬 모델과 시뮬레이션 결과를 통해서 EOTS의 전달정렬이 지연되는 요소가 방위각 오차임을 식별하였다. 그리고 EOTS의 방위각 오차 해소를 위해 항공기의 가속도 기동 및 EOTS의 자세 변화가 요구됨을 확인하였다. 최종적으로 OOO 항공기 체계에 적용한 비행시험 결과, 항공기 가속도 약 0.2g 이상이 발생하면서 EOTS가 6.7deg/s 각속도로 고각 운동 시 그렇지 않을 때보다 5배 이상 빠르게 정렬이 완료되어 전달정렬 성능이 개선되었다.