• Title/Summary/Keyword: Wheels

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A Study On Steering System for Mobile Robot with Permanent Magnet Wheels (영구자석 바퀴를 이용한 이동 로봇의 조향 시스템 연구)

  • Kim Jin-Gak;Yi Hwa-Cho;Han Seung-Chul
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.311-312
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    • 2006
  • In this paper, steering systems for mobile robot with permanent magnet wheels are discussed. The mobile robot with permanent magnet wheels can have three different types of steering and driving configurations; two-wheels, three-wheels, four-wheels. By a Two-WD(Wheel Driving) system, driving and steering characteristics are controlled by ratio of each wheel speeds. Three-WD system is steered by a front wheel and driven by rear wheels. Four-WD system has better stability than two wheel system. Usually the permanent magnet wheel has nearly none slip. Thus turning radius of the mobile robot with three-WD and four-WD System will be increased and the steering and driving system will be complicated. To solve this problem, two magnet wheels with two dummy wheels are used in this study. fuming radius of the developed mobile robot is small and the structure of the robot is simple. It is possible to move forward, backward, to turn left and right, and to rotate freely with two-WD. This study proved that two-WD system is very suitable fur the mobile robot with permanent magnet wheels.

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A Study on the development of wheels' direction indicator (자동차 바퀴 방향 지시기 개발에 관한 연구)

  • Cho, Chong-Duck;Shin, Seung-Sik
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.76-82
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    • 2006
  • Wheels' Direction Indicator, an electronic direction displaying system, provides a driver with information of wheels' direction in real time. The purpose of this study is to develop the system showing on LCD and LED with measuring steering wheel's movement. This system that applies a steering wheel's movement to the data process part will reduce inconvenience that confirms wheels' direction before throughout the open window before driving a car in parking lot.

The characteristic of low pressure casting AZ91D Magnesium alloy wheel (저압주조방식에 의한 AZ91D 마그네슘 휠 특성)

  • Kim, Kwang-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.4963-4967
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    • 2012
  • In this study, 18-inch wheels, magnesium alloy AZ91D was developed and we compared overseas go on sale magnesium wheels and same specifications of the aluminum wheels mechanical properties. Prototype 18-inch magnesium wheels by a low-pressure casting method to achieve the same specifications of aluminum wheels and reduced 26% of the weight, the new edition of magnesium wheels compared to the same level of elongation, tensile strength, hardness. Casting and heat treatment process to improve future need to improve the yield strength is expected.

STUDY ON THE ATTITUDE CONTROL OF SPACECRAFT USING REACTION WHEELS (반작용휠을 이용한 위성체 자세제어 연구)

  • 두주영;최규홍;이상욱
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.245-250
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    • 1998
  • Attitude determination and control of satellite is important component which determines the accomplish satellite missions. In this study, attitude control using reaction wheels and momentum dumping of wheels are considered. Attitude control law is designed by Sliding control and LQR. Attitude maneuver control law is obtained by Shooting method. Wheels momentum dumping control law is designed by Bang-Bang control. Four reaction wheels are configurated for minimized the electric power consumption. Wheels control torque and magnetic moment of magnetic torquer are limited.

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A Study on the Grinding Characteristics for Various Grinding Wheels in the Cylindrical Grinding (원통연삭시 연삭휠의 종류에 따른 연삭 가공특성에 관한 연구)

  • Lee, Choong-Seok;Chae, Seung-Su;Kim, Taeck-Su;Lee, Sang-Min;Park, Hwi-Keun;Lee, Jong-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.1
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    • pp.3-8
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    • 2008
  • This paper reports some experimental results of cylindrical external grinding using CBN wheels. Many experimental studies for surface grinding have been done, but not for the cylindrical grinding due to the difficulty of grinding force measurement. In this paper a new experimental device has been proposed for the grinding force measurement in cylindrical grinding. The cylindrical grinding experiments were carried out at various grinding conditions with several CBN grinding wheels. The experimental results indicate that the CBN wheels with smaller grains result in the higher grinding forces in both SCM415 and STD11 workpieces. The grinding forces of all wheels were proportional to the infeed speeds and the difference of each wheels was prominent at high infeed speed for SCM415.

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A Study on the Steering Wheel Vibration affected by the Fastening Torque of the Wheel Mounting Hub Bolts of Steel Wheels (스틸휠의 체결력에 따른 조향휠 진동에 관한 연구)

  • 안세진;정의봉;유완석;김명규
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.4
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    • pp.189-195
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    • 2003
  • The steel wheels are widely used in the passenger cars because of their low cost of production although the aluminum wheels have many advantages in their performance and appearance. It is known that the steering wheel vibration with steel wheels is generated more often than one with aluminum wheels. Both the constant velocity driving test and the m up test are carried out in this study to analyze the causes and path of the steering wheel vibration generated from the steel wheels. And this study shows that the steering wheel vibration is affected by the fastening torque of the wheel mounting bolts between the steel wheel and the suspension disk.

Motion Control of an Omnidirectional Mobile Robot with Steerable Omnidirectional Wheels

  • Byun, Kyung-Seok;Song, Jae-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.37.6-37
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    • 2002
  • Omnidirectional mobile robots are capable of arbitrary motion in an arbitrary direction without changing the direction of wheels, because they can perform 3 degree-of-freedom (DOF) motion on a 2-dimensional plane. In this research, a new class of an omnidirectional mobile robot is proposed. Since it has synchronously steerable omnidirectional wheels, it is called an omnidirectional mobile robot with steerable omnidirectional wheels (OMR-SOW). It has 3 DOFs in motion and one DOF in steering. One steering DOF can function as a continuously variable transmission (CVT). CVT of the OMR-SOW increases the range of velocity ratio from the wheel velocities to robot velocity, which may improve...

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Time Optimal Attitude Maneuver Strategies for the Agile Spacecraft with Reaction Wheels and Thrusters

  • Lee Byung-Hoon;Lee Bong-Un;Oh Hwa-Suk;Lee Seon-Ho;Rhee Seung-Wu
    • Journal of Mechanical Science and Technology
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    • v.19 no.9
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    • pp.1695-1705
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    • 2005
  • Reaction wheels and thrusters are commonly used for the satellite attitude control. Since satellites frequently need fast maneuvers, the minimum time maneuvers have been extensively studied. When the speed of attitude maneuver is restricted due to the wheel torque capacity of low level, the combinational use of wheel and thruster is considered. In this paper, minimum time optimal control performances with reaction wheels and thrusters are studied. We first identify the features of the maneuvers of the satellite with reaction wheels only. It is shown that the time-optimal maneuver for the satellite with four reaction wheels in a pyramid configuration occurs on the fashion of single axis rotation. Pseudo control logic for reaction wheels is successfully adopted for smooth and chattering-free time-optimal maneuvers. Secondly, two different thrusting logics for satellite time-optimal attitude maneuver are compared with each other: constant time-sharing thrusting logic and varying time-sharing thrusting logic. The newly suggested varying time-sharing thrusting logic is found to reduce the maneuvering time dramatically. Finally, the hybrid control with reaction wheels and thrusters are considered. The simulation results show that the simultaneous actuation of reaction wheels and thrusters with varying time-sharing logic reduces the maneuvering time enormously. Spacecraft model is Korea Multi-Purpose Satellite (KOMPSAT)-2 which is being developed in Korea as an agile maneuvering satellite.

The Study on the Fatigue Life Prediction on Wheels through CAE (CAE를 이용한 자동차용 휠(wheel)의 피로수명 예측기법 연구)

  • 김만섭;고길주;김정헌;양창근;김관묵
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.2
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    • pp.117-122
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    • 2004
  • The fatigue life in wheels was predicted by simulating the experimental method using Finite-Element analysis. Based on a high frequency fatigue property, calculations of the stresses in wheels were performed by simulating the rotating bending fatigue test. Wheels made of an aluminum alloy(A356.2) were tested using a bending fatigue tester. Results from bending fatigue test showed a linear correlation between bending moment and stress amplitude. Consequently, Finite-Element calculations were performed by a linear analysis. In order to find stress-cycles curves, spoke parts of wheel were tested using a rotary bending fatigue tester. Also, highly accurate Finite-Element analysis requires regression lines and confidence intervals from these results. In conclusion, if the fatigue data related to the material and manufacturing procedure are reliable, the prediction on fatigue lift in wheels can be carried out with high accuracy.

Vehicle Dynamic Characteristics according to the Coherence of Road Roughness between Left and Right Wheels (좌우 바퀴 노면 거칠기 상관도가 차량 운동 특성에 미치는 영향)

  • Choi, Gyoo-Jae;Jang, Bong-Choon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.6
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    • pp.120-126
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    • 2006
  • Vehicle dynamic simulation has been carried out using the coherence of road roughness between left and right wheels. The generated twin tracks with the coherence of road roughness between left and right wheels are in good agreements with the measured coherence relation of left and right wheels. And these tracks reflect well on the roughness characteristics of real roads. Using the generated roads and multibody dynamic simulation program, vehicle dynamic simulation is performed. The vertical and roll motion analysis of a vehicle are carried out using the realistic road profiles with the coherence between left and right wheels and the results are in good agreements with the dynamic characteristics of a vehicle.