Transitional Buckling Model for Active Bending fukushima/pub/amam2013...Fig1. Transitional Buckling Model (TBM) Fig2. Simulation model Fig3. Simulation result Fig4. Vaulting height

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  • Fig1. Transitional Buckling Model (TBM)

    Fig2. Simulation model Fig3. Simulation result

    Fig4. Vaulting height Fig5. Map of height

    Transitional Buckling Model for Active Bending Effect in Pole Vault*Toshihiko Fukushima, Satoshi Nishikawa, Kazutoshi Tanaka, Yasuo Kuniyoshi

    Intelligent Systems and Informatics Laboratory, The University of Tokyo

    Intelligent Systems and Informatics Lab. http://www.isi.imi.i.u-tokyo.ac.jp/

    Abstract Tool-use enables us to achieve tasks that would be otherwise impossible to complete. That will be able to say in robotics. Pole vault is a method to exchange vaulters horizontal energy to vertical energy. Well-trained athlete actively bends a pole while pole planting phase and flying phase, so he get higher. However, previous pole vault model is not include the active bending effect. Therefore, in this study, we proposed Transitional Buckling Model which accounted for athletes active bending on the pole by combining Eulers buckling model and previous model. In addition, we found out how the robot should actuate the pole.

    Introduction Tool-use enables robot to achieve tasks that would be otherwise impossible to complete. Pole vault can exchange horizontal kinematic energy to vertical potential energy. Athletes active bending has a large effect to enhance vaulting height.

    Proposed Model

    Experiments & Results

    Conclusion Transitional Buckling Model was able to account active bending effect. Input bending moment improved the vaulting performance. We presented one of the way to use skillfully the flexible and complex tools.

    Advantage of Active Bending

    Treat active bending effect by varying end support coefficient C

    (phase-1) Planting phase: active bend -> increase C(phase-2)Straightening phase: negative bend -> decrease C

    2D simulation by solving equation of motion. Compare TBM with previous model - Compare the vaulting height at each initial velocity Analyze bending strategies for vaulting higher - Explore timing and speed of changing bending direction

    Skill of Active BendingActive bending improved performance of pole vault.

    Usage of hysteresis:Change virtual spring constant in pole bending and straightening

    Timing:when pole was bent maximally

    Rate:like a step inputTiming l [m/s]

    Rat

    e C(

    u)

    ramp

    step

    Vaultingheight [m]

    0

    6.8

    7.0

    7.2

    7.4

    7.6

    -5 5.

    .

    6 6.5 7 7.5 8 8.5 95

    6

    7

    8

    Vau

    lting

    hei

    ght H

    v [m

    ]

    Initial velocity v0 [m/s]

    PreviousTBM

    l + l0

    0

    l0

    fs

    v0

    x

    y

    O

    u

    h0

    m

    0-1-2-3-40

    1

    2

    3

    4

    x [m]

    y [m

    ]

    trajectory velocity

    fs

    C = 1C < 1

    fs fs

    C > 1 C = 2

    fs

    positivebend

    negativebend

    pinedsupport

    (phase-1) (phase-2) fixedsupport

    end-s

    uppo

    rt con

    dition

    Eulers buckling modelC = 1

    fs

    pinnedsupport

    C = 2

    fs

    fixedsupport

    previous pole vault model