• 제목/요약/키워드: Angular Velocity

검색결과 917건 처리시간 0.025초

실린더의 회전 주파수 진동이 Taylor 와류에 미치는 영향 (EFFECTS OF OSCILLATING FREQUENCY ON TAYLOR VORTICES)

  • 강창우;양경수
    • 한국전산유체공학회지
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    • 제14권3호
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    • pp.95-105
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    • 2009
  • We study time-periodic Taylor-Couette flow with the outer cylinder at rest and the inner one oscillating with a mean angular velocity. Varying the frequency of inner cylinder, we investigate the change of Taylor vortices at a given amplitude and a mean angular velocity. With a small frequency of modulation, we find that Taylor vortices appear and disappear periodically. With a higher frequency, Taylor vortices do not disappear, but the intensity of Taylor vortices modulates periodically. As the frequency increases, Taylor vortices modulate harmonically.

핸들조향속도를 고려한 4WS 제어방법에 관한 연구 (A Study on the 4WS Control Method with the Effect of Steering Wheel Angular Velocity)

  • 이영화;김석일;김대영;김동룡
    • 한국자동차공학회논문집
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    • 제4권3호
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    • pp.168-175
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    • 1996
  • Except the collision avoidance performance related to the rapid lane change, the 4WS vehicle has better dynamic stability and handling performance than the conventional 2WS vehicle which has close relation with the driver's safety, a 4WS conrol method with the effect of steering wheel angular velocity is proposed based on the fact that the driver steers abruptly the steering wheel to avoid the collision. And the effects of the proposed 4WS control method are investigated on the dynamic stability and handling performance by using the ISO lane change test code.

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Backstepping 제어기법을 이간한 위성체 선회기동의 비선형 제어기법 (Nonlinear Control Law for Spacecraft Slew Maneuver using Backstepping Control Law)

  • 김기석;김유단
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.4-4
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    • 2000
  • In this paper, the backstepping control method that is useful for cascade systems is applied to the slew maneuver of the spacecraft. The quaternion is used for representing the attitude of the spacecraft, because the reference trajectory of angular velocity has simple mathematical form. The conventional backstepping control has severa] problems such as slow convergence, trivial cancelling of nonlinear terms, and excessive control input. To overcome these problems, the modified backstepping control method which is redesign of Lyapunov function is proposed. To design a tracking function for angular velocity, it is necessary to estimate the process of maximum angular velocity, and therefore the estimation procedure using Bellman-Gronwall inequality is developed. To verify the effectiveness of the proposed control law, numerical simulation is performed and the results are compared with the exiting control scheme.

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이동체의 각속도를 이용한 위성수신안테나의 트레킹 알고리즘 (A Tracking Algorithm of Satellite Antenna Using Angular Velocity of Vehicles)

  • 민상희;우광준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.669-672
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    • 2003
  • This paper proposes a tracking algorithm for receiving satellite signal. Tracking algorithm uses the angular velocity of vehicle and the slope of received satellite signal for searching the maximum level of signal. The tracking algorithm is composed of two parts. One is the routine to maintain the acceptable signal in spite of the variation of angular velocity. The other is the fine tuning routine to search the maximum signal level by giving the weight factors to the slope of signal. Experimental results show that the proposed algorithm is efficient and stable.

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유체유동을 갖는 회전 외팔 파이프의 동특성에 미치는 끝단질량의 영향 (The Influence of Tip-mass on Dynamic Characteristics of Rotating Cantilever Pipe Conveying Fluid)

  • 윤한익;최창수;손인수
    • 대한기계학회논문집A
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    • 제27권11호
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    • pp.1824-1830
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    • 2003
  • The vibrational system of this study is consisted of a rotating cantilever pipe conveying fluid and the tip mass. The equation of motion is derived by using the Lagrange equation. The influences of the rotating angular velocity and the velocity of fluid flow in a cantilever pipe have been studied on the dynamic characteristics of a rotating cantilever pipe by the numerical method. The effects of a tip mass on the dynamic response of a cantilever pipe are also studied. The tip-amplitude and maximum tip-deflection of each direction are directly proportional to the tip mass of the cantilever pipe in steady state. It identifies that the influence of the fluid velocity and the rotating angular velocity of the cantilever pipe give much variation the bending tip-displacement of steady state and the bending tip-displacement of non-steady state, respectively. The influence of the rotating angular velocity gives much the deflection of axial direction.

임베디드 보드 기반의 교육용 차동 구동 로봇 플랫폼 개발 (Development of Embedded Board-based Differential Driving Robot Platform for Education)

  • 최현주;이동현
    • 대한임베디드공학회논문지
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    • 제17권2호
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    • pp.123-128
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    • 2022
  • This paper proposes a mobile robot platform for education that can experiment with various autonomous driving algorithms such as obstacle avoidance and path planning. The platform consists of a robot module and a remote controller module, both of which are based on the Arduino Nano 33 IoT embedded board. The robot module is designed as a differential drive type using two encoder motors, and the speed of the motor is controlled using PID control. In the case of the remote controller module, a command to control the robot platform is received with a 2-axis joystick input, and an elliptical grid mapping technique is used to convert the joystick input into a linear and angular velocity command of the robot. WiFi and Zigbee are used for communication between the robot module and the remote controller module. The proposed robot platform was tested by measuring and comparing the linear velocity and angular velocity of the actual robot according to the linear velocity and angular velocity commands of the robot generated by the input of the joystick.

레이저 계측기를 이용한 축의 비틀림 진동에 관한 실험적 기초 연구 (The Experimental and Basic Study on Torsional Vibration of Horizontal Rotating Shaft using a Laser Measuring Equipment)

  • 박일수
    • 동력기계공학회지
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    • 제13권1호
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    • pp.33-38
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    • 2009
  • In this study, the nose of cam in the automobile engine was modelled into circular disk to analyze the torsional vibration of the cam shaft. The distance between disks was fixed, but the diameter of disks was changed. The torsional vibration of the cam shaft was studied experimentally by the motion of the modelled disk with changing the disk diameter. And the sizes of the modelled disk were selected not to show the natural frequencies over all the experimental ranges. The torsional vibration meter used in this study has a laser system with non-contact measurement method, which can measure both torsional angular vibration velocity and torsional angular vibration displacement simultaneously. The Experimental analysis shows that the characteristics of the torsional vibration in the horizontal rotating shaft can be considerably affected by the arrangement of the modelled disks.

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유체유동 회전 외팔 파이프의 안정성에 미치는 끝단질량의 영향 (Influence of Tip Mass on Stability of a Rotating Cantilever Pipe Conveying Fluid)

  • 손인수;윤한익;김동진
    • 한국소음진동공학회논문집
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    • 제17권10호
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    • pp.976-982
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    • 2007
  • In this paper the vibration system is consisted of a rotating cantilever pipe conveying fluid and tip mass. The equation of motion is derived by using the Lagrange's equation. The system of pipe conveying fluid becomes unstable by flutter. Therefore, the influence of a rotating angular velocity, mass ratio, the velocity of fluid flow and tip mass on the stability of a cantilever pipe by the numerical method are studied. The critical flow velocity for flutter is proportional to the angular velocity and tip mass of the cantilever pipe. Also, the critical flow velocity and stability maps of the pipe system are obtained by changing the mass ratios.

스키 시뮬레이터 운동 시 하지 운동특성 분석 및 관성센서 파라미터를 이용한 스키 숙련도 평가 (Kinematic Analysis of Lower Extremity and Evaluation of Skill of Skier Using Parameters of Inertial Sensors During Ski Simulator Exercise)

  • 김정윤;안순재;박선우;신이수;김규석;김영호
    • 대한의용생체공학회:의공학회지
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    • 제35권3호
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    • pp.35-41
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    • 2014
  • In this study, joint angles of the lower extremity and inertial sensor data such as accelerations and angular velocities were measured during a ski simulator exercise in order to evaluate the skill of skiers. Twenty experts and twenty unskilled skiers were recruited for the study. All expert skiers held the certificates issued by the Korea Ski Instructors Association. A three-dimensional motion capture system and two inertial sensors were used to acquire joint movements, heel acceleration and heel angular velocity during ski simulator exercises. Pattern variation values were calculated to assess the variations in ski simulator motion of expert and unskilled skiers. Integral ratio of roll angular velocity was calculated to determine the parallel alignment of the two feet. Results showed that ski experts showed greater range of motion of joint angle, peak-to-peak amplitude(PPA) of heel acceleration and PPA of heel angular velocity than unskilled skiers. Ski experts showed smaller pattern variations than unskilled skiers. In addition, the integral ratio of roll angular velocity in ski experts was closer to 1. Inertial sensor data measurements during the ski simulator exercises could be useful to evaluate the skill of the skier.

HIGH ANGULAR RESOLUTION [Fe II] λ1.644 μ SPECTROSCOPY OF YSOS WITH SUBARU TELESCOPE

  • PYO TAE-SOO;HAYASHI MASAHIKO;NAOTO KOBAYASHI;TERADA HIROSHI;TOKUNAGA ALAN T.
    • 천문학회지
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    • 제38권2호
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    • pp.249-252
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    • 2005
  • We present results of the velocity-resolved spectroscopy of the [Fe II] $\lambda$1.644${\mu}m$ emission toward outflow sources with the Subaru Telescope at the angular resolution of 0.apos;16 ${\~}$ 0.apos;5 arcseconds. The observed sources are L1551 IRS 5, DG Tau, HL Tau and RW Aur, which are located in the Taurus-Aurigae Molecular Cloud, one of the closest star forming regions (0.apos;1 = 14 AU). We were able to resolve outflow structure in the vicinity of the sources at a scale of a few tens of AU. The position-velocity diagram of each object shows two velocity components: the high velocity component (HVC: 200 - 400 km $s^{-l}$) and the low velocity component (LVC: 50 - 150 km $s^{-l}$), which are clearly distinct in space and velocity. The HVC may be a highly collimated jet presumed from its narrow velocity width and high velocity. The LVC, on the other hand, may be a widely opened disk wind inferred from its broad velocity width and low velocity. The spectrum taken perpendicular to the L1551 IRS 5 outflow at its base shows that the LVC has a spatially wide subcomponent, supporting the above interpretation. We demonstrated that the [Fe II] 1.644 $\mu$ spectroscopy is a very powerful tool for the studies of fast jets and winds that directly emanate from star-disk systems.