• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.140-147
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• 2015

In this paper, we propose a state feedback robust controller of 2-axis gimbal system which have bounded parametric uncertainty. The proposed controller is robust against dynamics variations of gimbal system and contains a dynamic compensator in order to improve a steady state error and a transient response. The stability of the closed-loop system is proved by Lyapunov approach. The performance of the proposed method is demonstrated by simulation on a 2-axis gimbal system.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.468-469
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• 2008

항공기, 차량, 고속의 비행체 등과 같은 동적인 플랫폼에서 표적을 추적하기 위한 영상 추적 시스템은 시선을 안정화하는 외부의 추적루프와 내부의 안정화 루프를 포함하는 구조로 되어 있다. 2축 김발을 사용하는 영상 추적 시스템의 추적루프는 크게 영상 추적기, 추적 제어기, 안정화 루프 등으로 구성되어 있다. 본 논문에서는 영상 추적 시스템의 추적 제어기를 설계하여 성능을 분석하고, 또한 설계된 제어기를 적용하여 영상 추적기의 시간지연에 의한 추적 루프 특성을 분석하였다. 마지막으로 설계된 추적 제어기를 영상 추적 시스템 시뮬레이터에 적용하여 고기동 고속의 비행체 환경에서 추적 루프 성능을 분석하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.3
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• pp.187-194
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• 2019

The off-axis Infra-Red(IR) seeker is mounted on the nose cone side of the anti-air high speed missile to alleviate thermal shield effect due to aerodynamic heating. The seeker output can not be regarded as the Line-of-Sight(LOS) rate any more as missile's roll motion to keep the target tracking is associated. In this paper, we propose a method to calculate the LOS rate for off-axis seeker on a 2-axis gimbal. Firstly, true LOS rate equations are analytically derived but not implementable because boresight error rate is not measurable. And then the first order lag approximation to obtain boresight error rate is proposed. The proposed LOS rate calculation method can compensate the coupling effect by considering the rotations of missile and gimbal. The performance of the proposed method is verified via full nonlinear 6-DOF(Degree of Freedom) simulations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.162-165
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• 2004

A layout of regenerative liquid rocket engine using turbo pump has been designed for development of high performance liquid rocket engine. each components of engine system was placed by considering assembly and characteristic. first stage engine system is controled by one plane of axis gimballing and composed of four engine assembly to cluster with launch vehicle. second stage engine system is controled by two plane of axis gimballing and composed of one engine assembly. assembly and disassembly processes and required program have been developed. various shape of instruments were also developed for carrying out assembly and disassembly process efficiently

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.303-304
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• 2007

항공기, 차량, 유도탄 둥과 같은 동적인 플랫폼에서 표적을 추적하기 위해서 시선을 안정화하는 외부의 추적 루프와 내부의 안정화 루프(또는 속도 루프)가 있고, 또한 표적을 추적하기 전 표적을 지향하고 포착하기 위해 김발을 동체에 대해 일정한 각도로 유지하기 위한 위치 루프도가지고 있다. 일반적으로 안정화 루프는 각속도를 측정하기 위한 검출기로 자이로를 사용하고, 위치 루프는 김발각을 제어하기 위한 위치 검출기를 사용한다. 그러나 안정화 루프에 사용되는 자이로는 루프 성능을 최적으로 하기 위해서 고성능/고가의 자이로가 사용되는 단점이 있다. 따라서 본 논문에서는 위치 루프에 사용되는 위치 센서인 리졸버를 사용하여 고성능/고가의 자이로 센서 없이 안정화 루프를 설계하였고, 리졸버를 사용하여 설계된 안정화 루프가 동적인 플랫폼에 사용될 수 있는지 시뮬레이션 결과와 실험 결과를 통해 분석하였다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.1932-1934
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• 2001

In this paper, a horizontal LOS(line of sight) rate estimator for conventional sea skimming ASM(anti-ship missile) is proposed. A LOS rate dynamics model in 2 axis gimbal system and in homing geometry is derived. And a new LOS rate estimator is proposed by applying a Kalman filter theory to the LOS rate dynamics model. The proposed filter can estimate LOS rates with taking roll motions into account. Simulation results show the proposed filter produces smaller estimation errors than a conventional method.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.4
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• pp.508-519
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• 2018

This paper concerns on stabilization control of a gyro-stabilized 2-axes gimbal system which is mounted on a moving vehicles such as automobiles, armored vehicles, ships, flying vehicles, etc. A target image acquisition system is attached on the inner gimbal, and the gimbal systems are required to retain high stabilization accuracy in the absolute coordinate in order to provide fine target image while vehicle is moving. The stabilization control performance is hardly depended upon disturbance rejection ability of control, and disturbance feedforward compensation is effective because feedforward compensation reduce the amount of disturbance before the disturbance disturbs the systems. This paper suggests an experimental method which can estimate system parameters and disturbance torques by using 3-axes accelerometer mounted on the inner gimbal. Furthermore, a simple disturbance identification method which can be applied to any slanted base conditions has been suggested to identify mass unbalance vector and friction torques of each gimbal simultaneously. By using the estimated parameters, a feedforward compensation has been applied to the gyro-stabilized 2-axes gimbal system. The experimental results showed that the feedforward compensation based on the identification method suggested is effective to improve stabilization performances.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2386-2391
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• 2011

Tracking and detecting targets by the millimeter wave seeker is affected by moving of platform. In order to perform the tracking performance, stabilization of a millimeter wave seeker which consists of 2-axis gimbals was considered in this study. The feasibility of the analysis and the 2-axis gimbal servo system modeling design were verified along with some simulation results.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.1024-1030
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• 2001

In this paper, a horizontal LOS(line of sight) rate estimator for conventional sea skimming ASM(anti-ship missile) is proposed. A LOS rate dynamics model for a 2-axis gimbal system and the homing geometry is derived. A new LOS rate estimator is proposed by applying the Kalman filter theory to the LOS rate dynamics model. The proposed filter estimates LOS rates by taking roll motions into account. Simulation results show that the proposed filter produces smaller estimation errors than a conventional method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.5
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• pp.65-73
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• 2004

CMG(Control Momentum Gyro) is a control device being used for spacecraft attitude control constructing relatively large amount of torque compared to conventional body-fixed reaction wheels. The CMG produces gyroscopic control torque by continuously varying the angular momentum vector direction with respect to the spacecraft body. The VSCMG(Variable Speed Control Momentum Gyro) has favorable advantages with variable speed to lead to better control authority as well as singularity avoidance capability. Attitude dynamics with a VSCMG mounted on a two-axis gimbal system are derived in this study. The dynamic equation may be considered as an extension of the single-axis counterpart. Also, a feedback control law design is addressed in conjunction with the dynamic equations of motion.