• 대한기계학회논문집A
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• 제32권4호
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• pp.340-346
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• 2008

An unmanned surveillance robot consists of a machine gun, a laser receiver, a thermal imager, a color CCD camera, and a laser illuminator. It has two axis control systems for elevation and azimuth. Because the current robot system is mounded at a fixed post to take care of surveillance tasks, it is necessary to modify such a surveillance robot to be installed on an UGV (Unmanned Ground Vehicle) system in order to watch blind areas. Thus, it is required to have a stabilization system to compensate the disturbance from the UGV. In this paper, a simulation based design scheme has been adopted to develop a mobile surveillance robot. The 3D CAD geometry model has first been produced by using Pro-Engineer. The required pan and tilt motor capacities have been analyzed using ADAMS inverse dynamics analysis. A target tracking and stabilization control algorithm of the mobile surveillance robot has been developed in order to compensate the motion of the vehicle which will experience the rough terrain. To test the performance of the stabilization control system of the robot, ADAMS/simulink co-simulations has been carried out.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.473-480
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• 2005

A three axes marine satellite antenna has been developed. As a design step, a CAD model for the antenna has been created according to the design requirements. Kinematic analyses are carried out to insure design specification and to check collision detection of the CAD model. Marine satellite antennas experience base motions, and a relevant control system should control the three antenna axis to point to the satellites accurately. A sensor fusion algorithm and a PIDA (Proportional, Integral, Derivative, Acceleration) control algorithm are designed and implemented to control the yaw, level, and cross-level angle of a small size satellite marine antenna. Antenna stabilization control experiments are performed using a test simulator which gives the antenna base motions. Experimental results show small pointing errors, which is less than 0.2 degree for the level, cross-level, and yaw axis.

• International Journal of Aeronautical and Space Sciences
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• 제17권4호
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• pp.579-592
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• 2016

CNUSAIL-1, to be launched into low-earth orbit, is a cubesat-class satellite equipped with a $2m{\times}2m$ solar sail. One of CNUSAIL's missions is to deploy its solar sail system, thereby deorbiting the satellite, at the end of the satellite's life. This paper presents the design results of the attitude control system for CNUSAIL-1, which maintains the normal vector of the sail by a 3-axis active attitude stabilization approach. The normal vector can be aligned in two orientations: i) along the anti-nadir direction, which minimizes the aerodynamic drag during the nadir-pointing mode, or ii) along the satellite velocity vector, which maximizes the drag during the deorbiting mode. The attitude control system also includes a B-dot controller for detumbling and an eigen-axis maneuver algorithm. The actuators for the attitude control are magnetic torquers and reaction wheels. The feasibility and performance of the design are verified in high-fidelity nonlinear simulations.

• Journal of Advanced Marine Engineering and Technology
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• 제37권2호
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• pp.192-198
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• 2013

본 논문은 2축 구조를 가진 안정화 지향성 Pan-Tilt 시스템을 개발하기 위한 기초연구로서 2축 Pan-Tilt와 Pan-Tilt 구동 하드웨어 보드를 제작하고 표적 추적을 위한 제어기를 설계하는 내용이다. Pan-Tilt 시스템을 6 자유도 선박운동 시뮬레이터에 탑재하여 테스트 환경을 구축하고 RCGA를 이용하여 Pan-Tilt의 모델 매개변수를 추정한 다음, 추정된 모델과 RCGA에 기초하여 시뮬레이션과 실험을 수행함으로써 2 자유도 PID 제어기 동조의 유효성을 검토한다.

• 대한기계학회논문집A
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• 제36권11호
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• pp.1463-1471
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• 2012

본 논문은 3 축 영상 장치를 기존의 2 축 경계 로봇에 적용하는 설계안을 제시하고 이러한 기동형 경계 로봇의 영상 정보를 이용한 목표 추적 알고리즘을 제안하였다. 또한 가상 시뮬레이션을 이용하여 목표 추적 알고리즘을 검증하였다. 목표추적 알고리즘에서는 카메라 영상의 중심과 카메라 영상으로 포착된 목표물 중심 사이의 위치 에러를 이용하여 영상 장치의 목표 지향 벡터를 획득하고, 역기구학을 이용하여 획득한 목표 지향 벡터를 생성해 낼 수 있는 기동형 경계 로봇의 팬, 틸트 회전 요구 각도와 카메라 영상의 안정화를 위한 롤 회전 요구각도를 계산하였다. MATLAB 과 ADAMS 를 이용하여 기동형 경계 로봇의 가상 모델을 생성하고, 가상의 목표물의 움직임에 대한 가상 모델의 운동을 확인하여 영상 기반의 목표 추적 알고리즘을 검증하였다.

• International Journal of Aeronautical and Space Sciences
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• 제3권2호
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• pp.1-12
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• 2002

This paper considers the robust and optimal three-axis attitude stabilization of rigid spacecraft with inertia uncertainties. The attitude motion of rigid spacecraft described in terms of either the Cayley-Rodrigues parameters or the Modified Rodrigues parameters is considered. A class of robust nonlinear control laws with relaxed feedback gain structures is proposed for attitude stabilization of rigid spacecraft with inertia uncertainties. Global asymptotic stability of the proposed control laws is shown by using the LaSalle Invariance Principle. The optimality properties of the proposed control laws are also investigated by using the Hamilton-Jacobi theory. A numerical example is given to illustrate the theoretical results presented in this paper.

• 정보저장시스템학회논문집
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• 제5권1호
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• pp.14-18
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• 2009

This paper proposed an optimal plate spring design for the optical image stabilizer in mobile phones. The voice-coil motor (VCM) with plate spring is the smallest, lowest-cost solution for auto focus on the market today and it is also the simplest to implement. The VCM is selected in this paper for auto focusing. However, the design process is complex due to the many design variables coupled to each other and some constraints of each directional motion caused by the characteristics of plate spring. Because of the complex formulation of the design objective, a plate spring design is proposed through the design of experiments to find the optimal design satisfying design constraints.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.457-462
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• 2004

Active magnetic bearings (AMB's) have become practical in many industrial fields and numbers of studies for magnetic bearing systems have been reported. However, AMB systems are open-loop unstable and thus require feedback control for robust stabilization and performance. In this paper, first, a rotation of the rotor around the inertial axis is considered and a rigorous modeling of a magnetic bearing system in which the rotation of the rotor is on its axis of inertia is developed. Next, to stabilize the AMB system a PID controller is used and experimentally analyze its rotational response.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.426-430
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• 2005

통신해양기상위성(COMS)는 국내 최초로 개발되는 3축 안정화 복합위성으로 2008년에 지구정지궤도(GEO, Geostationary Earth Orbit)에 발사될 예정이다. 통신해양기상위성 추진시스템은 위성체의 지구정지궤도 진입, 자세 및 궤도 제어/조정을 위하여 요구되는 추력과 토오크를 제공한다. 본 논문은 통신해양기상위성 추진시스템의 시스템 설계 및 주요 부품의 성능에 관하여 기술하고자 한다.

• ETRI Journal
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• 제17권3호
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• pp.1-16
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• 1995

An advanced real-time satellite simulator (ARTSS) has been developed to support the ground operations activities of the ETRI satellite control system, such as testing of the system facilities, validation of flight control procedures, verification of satellite commands as well as training of the ground operators. The design of ARTSS is based on the top-down approach and makes use of a modular programming to ensure flexibility in modification and expansion of the system. Graphics-based monitoring and control facilities enhance the satellite simulation environment. The software spacecraft model in ARTSS simulates the characteristics of a geostationary communication satellite using a momentum bias three-axis stabilization control technique. The system can be also interfaced with a hardware payload subsystem such as Ku-band communication transponder to enhance the simulator capability. Therefore, ARTSS is a high fidelity satellite simulation tool that can be used on low-cost desk top computers. In this paper, we describe the design features, the simulation models and the real-time operating functions of the simulator.