• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.521-528
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• 2018

Military vehicles use run-flat wheels for emergency situations. Run-flat wheels can run required distance in a defined duration with the pressure loss tire. For the application of a run-flat system, wheels are designed in 2 pieces, including an inner rim and outer rim. These rims are assembled using clamping bolts. Clamping bolts determine the durability of military vehicle wheels because fracture of clamping bolts account for most wheel failures. For improving wheel durability, clamping bolt durability must be improved. In this study, wheel test conditions and bolt design were investigated. Existing test standards are not sufficient to conduct endurance tests. Supplementary conditions were investigated. Using these modified test conditions, the durability of wheels including clamping bolts was tested and verified. Results found the durability of wheels improved more than 168%. This study also proposes improvements in the design process of clamping bolts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1395-1400
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• 2007

Tire flat spot is a deformation which occurs around the contact patch during long-period parking and does hardly recovered even after driving. The deformation makes a tire self-excited and ride comfort gets worse. In this study, it is shown that the flat spot can be evaluated by measuring change in radial run out or force. Its effects on vibration at vehicle floor and steering wheel are also revealed. Finally it is shown that the flat spot is likely to occur if the inflation pressure is low and the tire is suppressed by a heavy load at a high temperature.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.185-195
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• 2000

This pacer studied on the lateral motion and yaw motion of the gantry crane which is used for the automated container terminal with two driving wheel types. Though several problems are occcurred in driving of gantry crane, they are solved by the motion by the operators. But, if the gantry crane is unmanned, it is automatically controlled without any operation. There are two types, cone and flat t y pin driving wheel shape. In cone type, lateral vibration and yaw motion of crane are issued. In flat type, the collision between wheel-flange and rail or the fitting between wheel-flanges and rail is issued. Especially, the collision between wheel-flange and rail is a very critical problem in driving of unmanned gantry crane. To bring a solution to the problems, the lateral and yaw dynamic equations of the driving mechanism of gantry crane with two driving wheel types are derived. Then, we investigate the driving characteristics of gantry crane. And this study used PD(Proportional-Derivative) Controller to control the lateral displacement and yaw angle of the gantry crane. The simulation result of the driving mechanism using the Runge-Kutta Method is presented in this paper.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.3
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• pp.17-26
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• 2004

In this paper, power transmission systems converts the shaft power of a Turbo-shaft Engine with Free Power Turbine into the generator power and be composed of a method being supplied in the thrust motor driving a propellers. Being used this, Gas turbine engine works to flat rating about 110 kw (147 shp) that the thrust motor be extremely supplied from the engine of 317shp. In this test equipment, the engine is installed with the flywheel being able to the damping function when happen to the varying load between gas turbine engine output-shaft and generator. Then if the flywheel of inertial moment be not considered, the generator and motor not get the required power from the engine for raising the load. Also it is certified that the engine works the abnormal operation. Hence the flywheel of inertial moment is determined the required range to do the performance analysis with the dynamic transient from the given and tested engine data. This system is able to get the required power after a mounting test with the redesigned flywheel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.545-550
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• 2001

This paper studied on the lateral motion and yaw motion of the gantry crane that is used for the automated container terminal. Though several problems are occurred in driving of the gantry crane, they are solved by the motion by the operators. But, if the gantry crane is unmanned, it is automatically controlled without any operator. There are two types, cone and flat type in driving wheel shape. In cone type, the lateral vibration and yaw motion of crane are issued. In flat type, the collision between wheel-flange and rail or the fitting between wheel-flanges and rail is issued. Especially, the collision between wheel-flange and rail is a very critical problem in driving of unmanned gantry crane. To bring a solution to the problems, the lateral and yaw dynamic equations of the driving mechanism of two driving wheels are derived. Then, we investigate the driving characteristics of gantry crane. In this study, the proposed controller, based on Model Based Controller, is used to control the lateral displacement and yaw angle of the gantry crane. And the availability of the proposed controller is showed through the comparison with the result of the proposed controller and PD controller. The simulation results of the driving mechanism, using the Runge-Kutta Method that is one of the numerical analysis methods, are presented in this paper.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.74.1-74.1
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• 2016

미국 텍사스 주 맥도날드 천문대에 위치한 2.1m 망원경에 부착된 SQUEAN (SED Camera for QUasars in EArly uNiverse)은 2010년부터 운용되고 있는 CQUEAN을 바탕으로 개발된 적외선 영역 광학기기이다. 20개의 필터 장착이 가능한 필터 휠 제어 시스템을 가지고 있는 SQUEAN 시스템은 SMOP (SQUEAN Main Observation software package), KFC82 (KHU Filter wheel Control software package for McDonald 82 inch Telescope), KAP82 (KHU Auto-guiding software Package for McDonald 82 inch Telescope) 등으로 구성되어 있다. 그러나 대형 필터 휠을 제어하는 모터의 토크부족과 감속기의 백래시(Backlash)의 영향으로 오프셋의 오차가 커서 초기위치의 재설정 없이 하룻밤 이상 관측을 지속하는데 어려움이 있었다. 토크가 크고 인코더가 장착된 모터 교체와 제어 프로그램 등을 변경하고, 백래시의 영향을 최소화할 수 있도록 소프트웨어로 보정하였다. 또한, SMOP로부터 네트워크 통신을 통해 초기화용 필터 마스크(Initial Filter Mask:IFM)를 제작하여 돔 플랫 이미지에서 정확한 필터의 위치를 측정하는 기능을 도입하였다. 이 발표에서는, 개선된 하드웨어 및 소프트웨어의 내용과 테스트한 결과에 대해 보여준다.