• 한국소음진동공학회논문집
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• 제14권12호
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• pp.1347-1353
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• 2004

With respect to the researches of the optical flying head(OFH) , the head-gimbal assembly should be analyzed to guarantee the stable fabrication and the characteristics of shock resistance. The suitable design is proved through the Probabilistic analysis of the design parameters and material properties of the model. Probabilistic analysis is a technique that be used to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can find out how much the results of a finite elements analysis are affected by uncertainties in the model. Another factor is analysis of the dynamic shock analysis. For the mobile application, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes in contact with outer shock disturbance. the system gets critical damage in head-gimbal assembly or disk. This paper describes probabilistic and dynamic shock analysis of head-gimbal assembly in micro MO drives using OFH slider.

• 한국전자통신학회논문지
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• 제19권2호
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• pp.437-444
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• 2024

회전형 관성항법시스템은 IMU(: Inertial Measurement Unit)를 김블 위에 장착하고 김블을 규칙적으로 회전시켜 IMU의 오차를 상쇄시킴으로써 보다 정확한 항법 정보를 제공할 수 있다. 그러나 파도에 의해 자세 변화가 생기면 회전절차의 한 주기가 끝나는 시점에 자세 오차가 0으로 상쇄되지 않게 되어 큰 위치 오차를 유발한다. 본 논문에서는 이 문제를 고려하여 항체의 롤각 정보를 기반으로 외부 김블을 회전시켜 안정화를 시키는 방법을 제안한다. 시뮬레이션을 기반으로 파도에 의한 영향을 분석하고 외부 김블 안정화의 성능을 검증한다.

• 로봇학회논문지
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• 제17권3호
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• pp.288-295
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• 2022

This study shows a system identification method of a balancing loading device for a stair climbing delivery robot. The balancing loading device is designed as a 2-axes gimbal structure and is interpreted as two independent pendulum structures for simplifying. The loading device's properties such as mass, moment of inertia, and position of the center of gravity are changeable for luggage. The system identification process of the loading device is required, and the controller should be optimized for the system in real-time. In this study, the system identification method is based on least squares method to estimate the unknown parameters of the loading device's dynamic equation. It estimates the unknown parameters by calculating them that minimize the error function between the real system's motion and the estimated system's motion. This study improves the accuracy of parameter estimation using a null space solution. The null space solution can produce the correct parameters by adjusting the parameter's relative sizes. The proposed system identification method is verified by the simulation to determine how close the estimated unknown parameters are to the real parameters.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.189-194
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• 2004

As a disk drive becomes widely used in portable environments, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes In contact with outer shock disturbance, the system gets critical damage in head-gimbal assembly or disk. This paper describes analysis of a HGA(head-gimbal assembly) in micro MO drives to shock loading during both non-operating state and operating state. A finite element model which consists of the disk, suspension, slider and air bearing was used to find structural response of micro MO drives. In the operational case. the air bearing is approximated with four linear elastic springs. The commercially available finite element solver, ANSYS/LS-DYNA, is used to simulate the shock response of the HGA in micro MO drives. In this paper, the mechanical robustness of the suspension is simuiated considering the shock responses of the HGA.

• 융합신호처리학회논문지
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• 제14권2호
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• pp.117-123
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• 2013

서보 시스템에서 마찰과 같은 비선형 요소는 측정이 어려우며, 또한 정확한 예측이 어려워 보상하기가 쉽지 않다. 특히, 2축 안정화 짐벌 시스템에서 마찰은 큰 오차를 발생시켜 최종적으로 제어 성능을 만족시키지 못한다. 이와 같은 문제점을 해결하기 위해 관측기 등을 적용한 마찰 보상 연구가 많이 진행되어 왔으나 특정 조건에서만 적용되어 군수 분야에서 정밀도를 요하는 2축 안정화 짐벌 시스템에 적용하는데 제한적이다. 본 논문에서는 가장 일반적이면서 강인성이 입증된 PID 알고리즘을 변형시킨 PI-LEAD 알고리즘을 사용하여 모델링 및 시뮬레이션을 통해 마찰 보상 효과를 입증하고, 실제 2축 안정화 짐벌 시스템에 적용하여 효과를 검증한다. 성능시험을 통해 PI-LEAD 알고리즘이 마찰에 의한 오차를 최소화하여 정밀 서보 시스템에서 요구하는 성능을 만족하는 것을 검증하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.627-630
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• 2009

해상용 Multi Sensor Surveillance System은 다양한 기술의 복합체로서 본 과제에서 개발하고자하는 Gyro Sensor based Servo Motion Control 알고리즘은 선박의 6자유도운동을 분석하여 그에 대응할 수 있는 Motion Control 동요안정화제어장치를 개발하는 것이며, Nano Driving Precision Pan-Tilt/Gimbal System은 초정밀 초고속으로 감시용 디바이스를 적시에 정확한 동작을 수행하게 해주는 필수적인 장비이다. 최종적으로 개발하고자 하는 분야는 해상용 Nano Driving Multi Sensor Surveillance System 중 Nano Driving Precision Pan-Tilt/Gimbal의 최적설계 및 제작, 3-axis Gyro Sensor based Servo Motion Control 알고리즘 개발, 영상추적 Video Tracking Software 및 Hardware의 개발 및 각 세부주관에서 개발한 각각의 장비를 하나의 시스템으로 통합하는 시스템 Integration 및 시험인증으로 하나의 시스템을 완성 하였다.

• 대한임베디드공학회논문지
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• 제8권3호
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• pp.129-136
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• 2013

In this paper, a motion control system based on 2-axis gimbal system is designed and implemented to drive a high speed and precision. The proposed system consists of the RS-422 interface, 2-axis gimbal platform, servo control unit integrated with a high speed DSP chip-set, servo amplifier unit, potentiometer sensor unit, and resolver sensor unit. The servo control unit using the high speed DSP firmware is designed to get a fast response without an overshoot with step input and a RMS error of low probability with ramp input. The servo amplifier unit using a voltage control is designed to resolve the zero-crossing distortion for precise motion. To verify the performance and stability of the implemented system, experiments are performed through a measurement of the time and frequency domain response in a laboratory environment by using a PXI(PCI eXtentions for Instrumentation).

• 한국항공우주학회지
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• 제32권10호
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• pp.83-92
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• 2004

본 논문에서는 KSR-III 김발엔진 구동장치의 공진현상을 감쇠시키기 위한 서보필터 설계 결과를 제시하였다. 자세제어를 위한 김발엔진 구동장치를 엔진 지지구조물에 부착시켰을 때 저주파 영역에서 구조물과 구동장치 유압 모드간의 공진 현상이 발생하였고 이러한 공진현상을 감쇠시키기 위하여 서보필터의 설계가 요구되었다. 서보필터의 설계 과정으로 김발엔진 구동장치의 동특성 시험을 기반으로 서보필터 형상을 먼저 결정하고 보완 라그랑지안 공진화 기법을 이용하여 필터 파라미터의 최적값을 계산하였으며 최종적으로 비행용으로 적합한 서보필터를 결정하였다.

• 로봇학회논문지
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• 제11권4호
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• pp.262-269
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• 2016

Flight of an autonomous unmanned aerial vehicle (UAV) generally consists of four steps; take-off, ascent, descent, and finally landing. Among them, autonomous landing is a challenging task due to high risks and reliability problem. In case the landing site where the UAV is supposed to land is moving or oscillating, the situation becomes more unpredictable and it is far more difficult than landing on a stationary site. For these reasons, the accurate and precise control is required for an autonomous landing system of a UAV on top of a moving vehicle which is rolling or oscillating while moving. In this paper, a vision-only based landing algorithm using dynamic gimbal control is proposed. The conventional camera systems which are applied to the previous studies are fixed as downward facing or forward facing. The main disadvantage of these system is a narrow field of view (FOV). By controlling the gimbal to track the target dynamically, this problem can be ameliorated. Furthermore, the system helps the UAV follow the target faster than using only a fixed camera. With the artificial tag on a landing pad, the relative position and orientation of the UAV are acquired, and those estimated poses are used for gimbal control and UAV control for safe and stable landing on a moving vehicle. The outdoor experimental results show that this vision-based algorithm performs fairly well and can be applied to real situations.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권1호
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• pp.38-44
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• 2003

In this study, the balance beam control subsystem, new type of construction machinery using the mechanism of CMG (control moment gyro), for the attitude control of an unstructured object such as a beam carried by a tower crane, is designed and implemented. The balance beam controller consists of a wheel spinning at high speed and an outer gimbal for controlling the attitude of the wheel. Two motors, one for the wheel and the other for the gimbal, are used. Applying force to the spin axis of the wheel, as an input of the system, leads the torque about the axis because of the gyro effects. This torque is used to control the attitude of the unstructured object in this study. For the stabilizer function, in addition, holding the load at the current position, the attitude of the wheel is freed by cutting the power applied to the gimbal motor of the balance beam controller, which result in the braking force to stop the load by gyro effect. The works presented here include the mechanical system of the balance beam controller, the remote controller, the servo controller and the control software for the system. We also present experimental results to show that the system we proposed is useful as a new construction machinery which can control the attitude of the beam hanging from a tower crane.