• Title/Summary/Keyword: body tilting

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Characterization of the Tilting Link Mechanism for the Tilting Train (틸팅차량용 틸팅 링크메커니즘의 특성연구)

  • Kim Nam-Po;Kim Jung-Seok
    • Journal of the Korean Society for Railway
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    • v.8 no.1
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    • pp.34-40
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    • 2005
  • This study presents parametric studies for design of a tilting mechanism to be used in 180km/h tilting train. The tilling mechanism is composed of 4 links, a lilting bolster old an electro-mechanical actuator. The movements of the tiling center, CG of the train body, coupler center and tilting actuator along variation of upper and lower span length have been verified by the kinematic analysis. Moreover, the inclination angle and the stroke of the tilting actuator according to the variation of the tilting angle from +8 degrees to -8 degrees have been investigated. From this study, the relation between the movements of the CG of the train body, coupler center and tilting actuator and the height of the tilting center could be evaluated.

The Study on the Kinematics of Carbody Tilting Mechanism for Railway Vehicles (철도차량용 차체틸팅기구의 기구학적 특성연구)

  • 김정석;김남포;고태환
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.384-388
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    • 2004
  • This study presents parametric studies for design of tiling mechanism to be used in 180km/h tilting train. The titling mechanism is composed of 4 links, a tilting bolster and an electro-mechanical actuator. First we have determined the installation height of tilting actuator using 3D tilting bogie modeling. Secondary, we verified movements of the tiling center and train body CG along variation of upper and lower span length. From this study, we obtained the upper and lower span length to minimize the lateral and vertical motion of CG of train body. Finally, we evaluated the tilting actuator force and power required to tilt the train body to $\pm$8$^{\circ}$.

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Dynamic Analysis of a Bogie Tilting Mechanism (대차 틸팅 기구의 동적 해석)

  • 구동회;김남포;한형석
    • Journal of the Korean Society for Railway
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    • v.6 no.4
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    • pp.300-307
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    • 2003
  • Using a conventional railway, a tilting train was applied as a means of improving vehicle speed curve negotiation without any modification of infrastructure. In order to achieve the optimal car-body position control through the tilting mechanism, a dynamics analysis was required after the kinematics analysis of the tilting mechanism. For this, the geometric relationship of the linkage-type tilting mechanism was defined. Then, the equations of motion for the half car-body were derived. With the derived equations, the effect of the parameter change on performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational conditions in which the tilting vehicle is applied.

Lumbar Spine Kinematics during Anterior and Posterior Pelvic Tilting in Supine and Prone Positions

  • Park, So-Hyun;Yuk, Goon-Chang;Ahn, Sang-Ho;Lee, Dong-Gyu;Choi, Jin-Ho;Oh, Hyun-Ju;Park, Kwan-Yong
    • The Journal of Korean Physical Therapy
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    • v.23 no.6
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    • pp.9-14
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    • 2011
  • Purpose: The pelvic tilting exercise is a well recognized rehabilitation maneuver. However, little information is available on the changes of lumbar segmental motion during pelvic tilting. This study was conducted to measure the kinematics of the pelvic tilting exercise on the supine and prone positions via fluoroscopy. Methods: A total of 10 female subjects were enrolled. During anterior, neutral, and posterior pelvic tilting, radiographs were taken in each exercise via fluoroscopy (ARCADIS Orbic, Siemens, USA). Images were sent to the picture archiving communication system (PACS), and the digitized images were analyzed using LabVIEW software (National Instruments, USA). Lumbosacral lordosis and the intervertebral body angle, intervertebral disc angle, and intervertebral displacement were analyzed. Results: The results of lumbar kinematic analysis during three tilting postures in the supine and prone positions demonstrated that lumbosacral lordosis and the intervertebral body angle and intervertebral disc angle were significantly higher when the pelvis was tilted anteriorly (p>0.05). However, there was no significant difference between anterior and neutral tilting in the intervertebral disc angle at the L3/4 level in the prone position (p>0.05), and there was no significant difference among tilting positions in intervertebral body displacement in the prone position (p>0.05). Conclusion: This study provides scientific evidence about the pelvic tilting exercise in lumbosacral segmental motion. Depending on the pelvic tilting exercise, kinematic changes were demonstrated in both positions, especially in the supine position. It is suggested that the supine position is effective for mobility, but it should be used carefully for the LBP (Low back pain) patient with hypermobility.

Static Walking Algorithm for a Quadruped Robot using Tilting (틸팅을 이용한 4족 보행 로봇의 정적 보행 알고리즘)

  • Lee, Sun-Geol;Jo, Chang-Hyeon;Kim, Byeong-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.8
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    • pp.675-679
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    • 2001
  • This paper presents walking algorithm for a quadruped robot that does not have an upper body. Tilting motion is added to the planned walking trajectory instead of using an extra body segment that is independent on walking trajectory. Area and tracking algorithms are proposed as tilting method and compared with that of off-line tilting and that of no tilting. Computer simulation shows that stability of tilted walking is more improved than that of the usual walking algorithm for general walking paths. It also shows that the tracking method guarantees stability and best mobility.

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The Differences of Shoulder Muscle Activity Onset Time according to Body Tilting Angle in Push-up Exercise (Push-up 동작 시 신체기울기에 따른 견관절 주변근의 수축 개시시간 변화)

  • Cho, Yong-Ho;Kim, Sung-Ok;Choi, Jin-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.2
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    • pp.55-61
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    • 2015
  • PURPOSE: The purpose of this study was to investigate recruiting order and onset time around shoulder muscle during the push-up according to the body tilting angle. METHODS: Twenty healthy young adult subjects were recruited for this study. They had no neurological and musculoskeletal disease. We used the sEMG for recording onset time of shoulder muscles. Shoulder Muscles were anterior deltoid(AD), posterior deltoid(PD), pectoralis major(PM), upper trapezius(UT). Body tilting angle were measured at 0 degree, 30 degree and 60 degree by using tilting table. Muscles contraction onset time were set by the push-up performed 3 times respectively. Mean of 3 measurements were used. And initiate onset time was decided by the Mean ${\pm}2$ SD in the threshold, more than 25ms. RESULTS: There were significant difference at 0 degree, 30 degree and 60 degree(p<.05). Muscles onset time were same order at 0 degree, 30 degree. UT occurred first of all contraction at 0 degree and 30 degree. And then contracted AD, PD, PM. But, at 60 degree, AD was the first contraction, and PM, UT, PD. CONCLUSION: Muscle recruitment order and onset time according to the body tilting was shown the difference when you do push-up. Therefore, this result, shoulder muscle recruitment pattern of according to the body tilting is different and it has to make effective shoulder exercise program.

Static and Fatigue Fracture Assessment of Hybrid Composite Joint for the Tilting Car Body (틸팅차량용 차체의 Hybrid 복합재 접합체결부의 정적 및 피로 파괴 평가)

  • Jung, Dal-Woo;Kim, Jung-Seok;Seo, Sueng-Il;Jo, Se-Hyun;Choi, Nak-Sam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.2 s.257
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    • pp.166-173
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    • 2007
  • Fatigue fracture behavior of a hybrid bolted joint was evaluated in comparison to the case of static fracture. Two kinds of specimens were fabricated for the mechanical tests; a hybrid bolted joint specimen for the shear test and a hybrid joint part specimen applied in the real tilting car body for the bending test. Characteristic fracture behaviors of those specimens under cyclic toads were obviously different from the case under static loads. For the hybrid bolted joint specimen, static shear loading caused the fracture of the bolt body itself in a pure shear mode, whereas cyclic shear loading brought about the fracture at the site of local tensile stress concentration. For the hybrid joint part specimen, static bend loading caused the shear deformation and fracture in the honeycomb core region, while cyclic bend loading did the delamination along the interface between composite skin and honeycomb core layers as well as the fracture of welded joint part. Experimental results obtained by static and fatigue tests were reflected in modifications of design parameters of the hybrid joint structure in the real tilting car body.

Effects of Design Conditions in Five Pad Tilting Pad Bearing on the Lateral Vibration Characteristics of Small Gas Turbine (5패드 틸팅 패드 베어링의 설계 조건 변화가 소형 가스터빈의 횡진동 특성에 미치는 영향)

  • Ha, Jin-Woong;Myung, Ji-Ho;Suk, Jhin-Ik;Lee, An-Sung;Kim, Young-Cheol
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.8
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    • pp.752-760
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    • 2011
  • In tilting pad bearing design process, the selection of the proper configuration type of either a load-between-pad(LBP) or load-on-pad(LOP) as well as preload and pivot offset conditions is to be carefully considered. Also the bearing needs to be designed in order to be suited for the rotor-bearing system and operating condition. In this paper, it is observed that the dynamic characteristics in a five pad tilting pad bearing for the LBP and the LOP configurations are influenced by the variation of preload and pivot offset. In this context, rotor dynamic analysis of the 5 MW industrial gas turbine supported by the tilting pad bearing at the front and roller bearing at the rear is carried out based on the dynamic coefficients of the tilting pad bearing investigated. The result shows that two rigid body critical modes experience various changes according to the influence of the tilting pad bearing uniquely applied to one side of this machine. Mainly, the second critical speed, the rigid body mode of conical shape with high whirling in the tilting pad bearing, is significantly changed by preload and pivot offset regardless of the LBP and LOP configurations. And, the first critical mode, the rigid body mode of conical shape with high whirling in the roller bearing, is sensitively affected by preload applied to the LOP configuration and by its asymmetric dynamic properties.

Effects of Design Conditions in Five Pad Tilting Pad Bearing on the Lateral Vibration Characteristics of Small Gas Turbine (5패드 틸팅 패드 베어링의 설계 조건 변화가 소형 가스터빈의 횡진동 특성에 미치는 영향)

  • Ha, Jin-Woong;Myung, Ji-Ho;Suk, Jhin-Ik;Lee, An-Sung;Kim, Young-Cheol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.425-432
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    • 2011
  • In tilting pad bearing design process, the selection of the proper configuration type of either a Load-Between-Pad (LBP) or Load-On-Pad (LOP) as well as preload and pivot offset conditions is to be carefully considered. Also the bearing needs to be designed in order to be suited for the rotor-bearing system and operating condition. In this paper, it is observed that the dynamic characteristics in a 5 pad tilting pad bearing for the LBP and the LOP configurations are influenced by the variation of preload and pivot offset. In this context, rotor dynamic analysis of the 5MW industrial gas turbine supported by the tilting pad bearing at the front and roller bearing at the rear is carried out based on the dynamic coefficients of the tilting pad bearing investigated. The result shows that two rigid body critical modes experience various changes according to the influence of the tilting pad bearing uniquely applied to one side of this machine. Mainly, the second critical speed, the rigid body mode of conical shape with high whirling in the tilting pad bearing, is significantly changed by preload and pivot offset regardless of the LBP and LOP configurations. And, the first critical mode, the rigid body mode of conical shape with high whirling in the roller bearing, is sensitively affected by preload applied to the LOP configuration and by the its asymmetric dynamic properties.

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Design of a Two-wheeled Balancing Mobile Platform with Tilting Motion (횡방향 틸팅 기능을 갖는 이륜 밸런싱 모바일 플랫폼 설계)

  • Kim, Sangtae;Seo, Jeongmin;Kwon, SangJoo
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.1
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    • pp.87-93
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    • 2014
  • Conventional two-wheeled balancing robots are limited in terms of turning speed because they lack the lateral motion to compensate for the centrifugal force needed to stop rollover. In order to improve lateral stability, this paper suggests a two-wheeled balancing mobile platform equipped with a tilting mechanism to generate roll motions. In terms of static force analysis, it is shown that the two-body sliding type tilting method is more suitable for small-size mobile robots than the single-body type. For the mathematical modeling, the tilting-balancing platform is assumed as a 3D inverted pendulum and the four-degrees-of-freedom equation of motion is derived. In the velocity/posture control loop, the desired tilting angle is naturally determined according to the changes of forward velocity and steering yaw rate. The efficiency of the developed tilting type balancing mobile platform is validated through experimental results.