• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.863-868
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• 2015

In this paper, the vibration of a single-wheel mobile robot is minimized by designing a filter. An AHRS (Attitude and heading reference system) sensor is used for measuring the state of the robot. The measured signals are analyzed using the FFT method to investigate the fundamental vibrational frequency with respect to the flywheel's speed of the gimbal system. The IIR notch filter is then designed to suppress the vibration at the identified frequency. After simulating the performance of the designated filter using the measured sensor data through extensive experiments, the filter is actually implemented in a single-wheel mobile robot, GYROBO. Finally, the performance of the designed filter is confirmed by performing the balancing control task of the GYROBO system.

• 항공우주기술
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• 제2권1호
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• pp.153-163
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• 2003

전자 장비들은 전자파 간섭을 통해 다른 시스템에 영향을 주어서 오작동을 야기할 수도 있고 혹은 다를 시스템에 의해 자신이 오작동을 일으킬 수도 있다. 따라서 전자 장비들은 다른 시스템이 오작동을 일으키지 않는 범위에서 전자파 간섭을 주고 다른 시스템에서 전자파 간섭을 일으켜도 오작동을 일으키지 않도록 설계되어야 한다. 전자 장비들이 이러한 조건을 만족하는지를 확인하기 위해서는 전자파 환경시험을 하여야 한다. 본 논문에서는 KSR-III 김발엔진 구동 시스템에 있는 전자 장비들의 전자파 환경 규격과 시험 절차 및 결과를 소개하고자 한다.

• International Journal of Aeronautical and Space Sciences
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• 제8권1호
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• pp.105-114
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• 2007

This article presents the details of a designed control moment gyroscope (CMG) with a constant speed momentum wheel and one-axis-gimbal, and its experimental results performed at Korea Aerospace Research Institute. The CMG which is able to produce a torque of lOO mNm per each, is mounted in a pyramid configuration with four SGCMGs. Each CMG test and a single axis maneuver test with four-CMG cluster configuration are performed to confirm their performance on a ground-test facilities consisted of three major parts: a vibration isolation system, a dynamic force plate (Kistler sensor), and a DSP board. These facilities provide the accurate data of three axial and torques from the control moment gyro. Details of the CMG experimental results are presented with discussion of the experimental errors. The experimental data are compared with theoretical results and both results are used to verify their performance specifications.

• 대한기계학회논문집
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• 제18권6호
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• pp.1399-1411
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• 1994

A model helicopter has more versatile flight capability than the fixed-wing aircraft and it can be used as an unmaned vehicle in hazardous area. A helicopter, similar to other aircrafts, is an unstable, multi-input multi-output nonlinear system exposed to strong disturbance. So it should be controlled by robust control theories that can be applied to multivariable systems. In this study, motion equations of hovering are established, linearized and transformed into a state equation form. Various parameters are measured and calculated in other to obtain the stability derivatives in the state equation. Hovering flight controller is designed using the digital LQG/LTR(Linear Quadratic Gaussian/Loop Transfer Recovery) control theory. The designed controller is tested by the nonlinear simulations and implemented on an IBM-PC/386. Experiments were carried out on a model helicopter attached to the 3-DOF gimbal. The designed controller showed satisfactory hovering capability to maintain the hovering for more than 40 seconds.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.917-923
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• 2001

This paper presents the fabrication and testing results of a dual stage microactuator system for fine positioning of magnetic heads in hard disk drives. An electrostatic rotary microactuator was newly designed and fabricated. The microactuator was integrated into the head gimbal assembly of a disk drive system and its dynamic characteristics were investigated. Experimental results show that natural frequency and voltage gain of the microactuator are 4.3 KHz and 25 nm/V and the dual stage microactuator system achieves the tracking accuracy of 30 nm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.344-348
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• 1992

This paper describes a procedure to design a hovering flight controller for a model helicopter using LQG theory. Parameters of the model helicopter in hover are obtained using direct measurements and calculations proposed by other research. A feedback co is by using digital LQG theory. First, a full state feedback controller is designed to the discretized system taking desirable transient response and other assumptions into account. Then a full-state estimator is designed and revised until desirable response is obtained while global stability is maintained. Performance of the controller is tested by computer simulations. Experiments have been performed using a 3-degree-of-freedom gimbal that holds the model helicopter, and the controller exhibited stable hover capability.

• 센서학회지
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• 제5권4호
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• pp.47-56
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• 1996

속도제어루프내에서 외란의 각속도를 감지하여 짐발을 안정화시키기 위해 사용하는 동조자이로스코프에 대한 기본원리 및 특성을 분석하였다. 또한 비례모드 자이로스코프의 모델을 정확하게 제시하였으며, 제시된 모델은 공진 특성을 가지고 있기 때문에 기존에 사용하고 있는 2차 시스템 모델보다 실제 시스템의 특성과 유사하므로 일반적인 비례모드 자이로스코프에서도 적용 가능하다. 실제 시스템인 전자광학추적기에 사용할 경우 발생되는 문제점을 알아보고 그 해결 방안을 제시하였다.

• 한국정밀공학회지
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• 제13권5호
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• pp.30-37
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• 1996

The objective of this research is to explore the analysis and test method for the reliable design and fabrication of a high precision dynamically tuned gyroscope. The tuning frequency is decided by the calculation of mass moment of inertia of rotor and gimbal and the stiffness of flexures. Due to the complex geometry of the flexure, calculation of the stiffness of the suspension flexure is difficult. In this paper, three analytical methods for obtaining the stiffness of the flexure are porposed and a special testing method is used for checking the accuracy of the computed results.

• 항공우주기술
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• 제6권2호
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• pp.236-244
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• 2007

스마트무인기의 기본 비행성능 파악과 비행제어 알고리즘의 검증을 위하여 40% 축소형 비행체를 개발하였다. 축소형 비행체는 실물기와 유사한 형태의 짐발 허브와 드라이브 장치를 채택하였으며 강제 공랭 방식의 왕복엔진을 장착하였다. 축소형 비행체 주요 부품에 대한 다양한 시험을 수행하였고 조립된 축소형 비행체의 지상시험 및 호버링 시험을 통하여 주요 성능과 기계적 내구성을 확인하였다.

• 대한기계학회논문집A
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• 제33권8호
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• pp.760-766
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• 2009

In the manufacturing process of HDD, ball swaging method is commonly used to joint the Head Gimbal Assembly(HGA) with the arm of the actuator. The hub on the HGA is placed into the hole of the actuator arm, and the hub and arm is bonded by the pressure of steel ball. The pressure for plastic deformation on the baseplate causes the undesirable deformation on HGA, such as tilting, flying height change of head. After obtaining the key parameters that have large sensitivity on the swaging process, the optimal shape of baseplate is proposed to increase the static performance during swaging process. Contribution of the proposed design for the swaging performance is verified by contact simulation with elasto-plastic deformation.