• Title/Summary/Keyword: Handling stability

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Development of Tire Lateral Force Monitoring Systems Using Nonlinear Observers (비선형 관측기를 이용한 차량의 타이어 횡력 감지시스템 개발)

  • 김준영;허건수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.4
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    • pp.169-176
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    • 2000
  • Longitudinal and lateral forces acting on tires are known to be closely related to the tract-ability braking characteristics handling stability and maneuverability of ground vehicles. In thie paper in order to develop tire force monitoring systems a monitoring model is proposed utilizing not only the vehicle dynamics but also the roll motion. Based on the monitoring model three monitoring systems are developed to estimate the tire force acting on each tire. Two monitoring systems are designed utilizing the conventional estimation techniques such as SMO(Sliding Mode Observer) and EKF(Extended Kalman Filter). An additional monitoring system is designed based on a new SKFMEC(Scaled Kalman Filter with Model Error Compensator) technique which is developed to improve the performance of EKF method. Tire force estimation performance of the three monitoring systems is compared in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with the combined-slip Magic Formula tire model. The built in our Lab. simulation results show that the SKFMEC method gives the best performance when the driving and road conditions are perturbed.

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Electrostatic Suspension and Transportation Device of Glass Panels (정전기력을 이용한 유리 판넬의 비접촉 지지 및 반송)

  • Jeon Jong-Up
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.3 s.180
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    • pp.76-85
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    • 2006
  • In the manufacture of liquid crystal display devices, there is a strong demand for contactless glass panel handling devices that can manipulate a glass panel without contaminating or damaging it. To fulfill this requirement, an electrostatic transportation device for glass panels is proposed. This device can directly drive a glass panel and simultaneously provide contactless suspension by electrostatic forces. To accomplish these two functions, a feedback control strategy and the operational principle of an electrostatic induction motor are utilized. The stator possesses electrodes which exert electrostatic farces on the glass panel and are divided into a part responsible for suspension and one for transportation. To accomplish dynamic stability and a relatively fast suspension initiation time, the structure of the electrode for suspension possesses many boundaries over which potential differences are formed. In this paper, an electrode pattern suitable for the suspension of glass panels is described, followed by the structure of the transportation device and its operational principle. Experimental results show that the glass panel has been transported with a speed of approximately 25.6 mm/s while being suspended stably at a gap length of 0.3 mm.

CHARACTERIZATION AND CLASSIFICATION BY NEAR INFRARED SPECTROSCOPY OF WAXES USED IN DAIRY TECHNOLOGY

  • Barzaghi, Stefania;Giardina, Claudia;Cattaneo, Tiziana M.P.;Giangiacomo, Roberto
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1252-1252
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    • 2001
  • The aim of this study was to evaluate the possibility to characterize and classify waxes applied on some type of cheeses to obtain good stability during handling and transportation. Generally, waxes are obtained from the petrochemical industry, nowadays there is the possibility to also use biodegradable waxes produced from microorganisms. Preliminary studies were carried out to optimize sample presentation in NIR analysis, such as melting conditions (influence of temperature) and coat thickness of wax. 12 waxes (biodegradable or not) were analysed by using an InfraAlyzer 500 (Bran+Luebbe). The sample size was performed cutting pieces of 1.5 cm (height) x 1.5 cm (width) x 1.5 mm (thickness), previously melted at 9$0^{\circ}C$. NIR spectra were collected at room temperature, and data were processed by Sesame Software (Bran+Luebbe) to evaluate qualitative differences among samples by cluster analysis. Waxes were gathered on the basis of their origin (petrochemical or microbial). To better understand the significance of the NIRS bands discriminating among waxes, a two-dimensional correlation with FT-IR spectra, collected by a FT-IR/ATR 420 (JASCO) instrument, was made using 2DCORR program (Galactic Industries). On the basis of its classification power, NIRS appears to be a promising tool when used in routine analysis for a qualitative control of raw materials.

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A Study on Future Container Cranes (차세대 컨테이너크레인에 대한 고찰)

  • Jung Hyun-Soo;Lee Suk-Jae;Hong Keum-Shik
    • Journal of Navigation and Port Research
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    • v.29 no.3 s.99
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    • pp.291-298
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    • 2005
  • In this article. the specifications of a future container crane for a 18,000 TEU megaship are investigated After studying the transitions of containerships through the past half century, the characteristics of the past and current container cranes are outlined. together with various research trends throughout the world Upon these results, the size and performance of the container crane that will be used beyond the year 2014 are forecast. Specifically, the structure, trolley and hoist mechanism, control method, outreach. backreach, rail gage, loading capacity, stability, durability, and others are summarized.

A Study for the Prediction of a Tire Cornering Characteristics using a Finite Element Method (유한요소법을 이용한 타이어 코너링특성 예측에 관한 연구)

  • 김항우;조규종
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.1
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    • pp.151-162
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    • 1998
  • During a straight driving and cornering maneuver by a vehicle various forces and moments are exerted on the tire's footprint. A cornering properties, handling and stability performances of vehicle can be predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted using a finite element method. Contact area of the tire between bead and wheel are fixed to simplify of a finite element model. Lateral force is exerted on the rigid surface as a real load with Coulum friction after inflate and load vertically. Then, rotate the tire's axle to simulate a free rolling untill taken the equilibrium of a aligning torque. Also, experimental observations are made to test a reliability of a FE analysis conducted in this study. The finite element analysis said that good agreement was obtained with experimental results of these cornering properties, giving confidence within about one percent. So it os recommended that a finite element analysis can be used as a good tool to predicted the tire cornering properties.

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Preparation and Properties of W/O Emulsion by D Phase Emulsification (D상 유화물을 이용한 W/O 유화물의 제조와 특성)

  • Kim, H.J.;Jeong, N.H.;Yun, Y.K.;Park, K.S.;Nam, K.D.
    • Journal of the Korean Applied Science and Technology
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    • v.15 no.2
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    • pp.25-32
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    • 1998
  • The emulsion stability of W/O emulsion prepared by D phase emulsification during storage and handling is studied by using phase diagrams. The process of D phase emulsification begins with the formation of isotropic surfactant solution, followed by formation of oil-in-surfactant (O/D) gel emulsion by dispersion of octamethylcyclotetrasiloxane(OMCS) in the surfactant solution. Polyols were essential components for this purpose. To understand the function of polyols, the solution behavior of nonionic surfactant/oil/water/polyol systems were investigated by the ternary phase diagrams of polyoxyethylene oleyl ether/OMCS/propylene glycol(PG) aqueous solutions. The addition of PG increased the solubility of oil in the isotropic surfactant phase. D phase emulsification method has been applied to a new type of cosmetics. By using this emulsification technique, O/W emulsion were formed without a need for adjust of HLB. Fine and stable W/O emulsions were prepared by D phase emulsion.

Structure Analysis of the Light Robot Manipulator Capable of Handling Heavy Payloads (고가반 하중 이송가능한 경량 로봇 매니퓰레이터의 구조해석 연구)

  • Choi, Hyeung-Sik;Cho, Jong-Rae;Hur, Jae-Gwan;Chun, Chi-Kwang
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.2
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    • pp.318-324
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    • 2010
  • In this paper, the structure of the gravity compensator has been designed and applied to a light structure of a new 6-axis robot manipulator to enhance its torque performance. Also, analyses on the kinematics and inverse-kinematics of the manipulator have been performed. An FEM analysis has been performed on the structure of robot links to have an excellent performance of delivering 25 kg payload despite of 30kg weight, which is very light compared with other manipulators. Through the FEM analysis, the stability on the vending or fracture of the links of the robot manipulator has been verified.

Integrity Evaluation of Agitating Axis and Blade in the Organic Waste Reactor (유기성 폐기물 반응기 내부 교반 축 및 블레이드 건전성 평가)

  • Yun, Yu Seong
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.1-6
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    • 2017
  • Modern society has been experiencing by population growth and urbanization that bring, a change of eating habits which has occurred a various types of waste in a large amount. Even though these wastes are required an immediate treatment with difficulties unsanitary handling and existing waste treatment method are by incineration, fermentation, drying and etc. however a bad smell occurs after the treatment that need's a lot of energy in processing organic wastes with high moisture contents and wasteful and inefficient problem. The strength assessment of the organic waste agitating vessel is required in terms of safety due to the differences of loading on the shaft that was treated by agitating the mixture of food waste. The damage of agitating axis is depended on steam pressure, temperature condition and the force moment that exerted by the food waste. Thus the strength assessment and stability evaluation are very important, especially to handle a hard waste. In this study the rotation capacity of agitation is about 5 tons considering general structural rolled steel pressure vessel strength and steam pressure. The purpose is to estimate the safety and strength evaluation for a agitator axis and impellers according to the rotating angle of the axis under the condition of the 3.2 ton capacity reactor.

Development of Tire Lateral Force Monitoring System Using SKFMEC (SKFMEC를 이용한 차량의 타이어 횡력 감지시스템 개발)

  • Kim, Jun-Yeong;Heo, Geon-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.7 s.178
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    • pp.1871-1877
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    • 2000
  • Longitudinal and lateral forces acting at tire are known to be closely related to the tractive ability, braking characteristics, handling stability and maneuverability of ground vehicles. However, it is not feasible in the operating vehicles to measure the tire forces directly because of high cost of sensors, limitations in sensor technology, interference with the tire rotation and harsh environment. In this paper, in order to develop tire force monitoring system, a new vehicle dynamics monitoring model is proposed including the roll motion. Based on the monitoring model, tire force monitoring system is designed to estimate the lateral tire force acting at each tire. A newly proposed SKFMEC (Scaled Kalman Filter with Model Emr Compensator) method is developed utilizing the conventional EKF (Extended Kalman Filter) method. Tire force estimation performance of the SKFMEC method is evaluated in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with a combined-slip Magic Formula tire model.

The Operation Experience of the Concentrated Waste Drying System with Variation in the Mole Ratio of Boron to Sodium (방사성 폐액중의 붕소와 나트륨의 몰비 변화에 따른 농축폐액건조설비 운전 경험사례)

  • 김영식;김세태;안교수;박진석;박종길
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.220-225
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    • 2003
  • Generally, liquid radioactive wastes generated in nuclear power plant exist in powder form which do not contain moisture through the evaporating process of the Liquid Waste Management System and drying process of the Concentrated Waste Drying System. This powder form wastes are blended homogeneously with paraffin solidification agent and packed in metal drum to ensure its stability during handling and disposal. However, it was experienced that the powder form wastes were not blended homogeneously and separated into two layers in metal drum, on the other hand, a Portion of powder was adhered and solidified to the Inside parts of facility during the blending process. And the flaw of blending process above would come in case the mole ratio of Boron to Sodium in liquid radioactive wastes exceeds 0.2.

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