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gfraulini17-Peridot
17-Peridot
May 13, 2024
Question

Solve equations system for motion law

  • May 13, 2024
  • 3 replies
  • 1875 views

Hi folks,
it has been passed some years from my last use of mathcad...
I want to solve a system of equation by using the Solve Blok to find the coefficients for the displacement and velocity of a m otion law with "pure" traphezoid shape of the acceleration.
I don't understand where I'm wrong.
n. equations = n. of variables

    3 replies

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    ppal_25568718-Opal
    18-Opal
    May 14, 2024

    ppal_1-1715658075824.png

     

     

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    gfraulini17-PeridotAuthor
    17-Peridot
    May 14, 2024

    ra is the time the acceleration need to reach the max.

    gfraulini_0-1715659693368.png

     

    It is unknown and, by means of mu, it is inside every funzion of v or s.

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    Werner_E25-Diamond I
    25-Diamond I
    May 14, 2024

    Because you assume a symmetrical trpezoid, as I see it you only have three independent variables: a.max, r.a and TT !?

    But basically you have only one equation: s(T)=s.max with T= 4*r.a+2*TT and s(t) being the integral of the integral of a(t) from 0 to t.

    Because of symmetry we could also use s(T/2)=1/2*s.max

    So we should expect an infinite number of solutions (as Prime also says) and the 14 variables which you introduce would be highly dependable on each other, I guess.

    W
    Werner_E25-Diamond I
    25-Diamond I
    May 14, 2024

    I created  function d for displacement with the three parameters r.a, TT and a.max.

    You can choose any (reasonable) value for two of them and can derive the value of the third one so the max displacement is a given value (1 meter in the examples below):

    Werner_E_0-1715690175730.png

    Prime 10 worksheet attached

     

    A
    anursinghCommunity Manager
    Community Manager
    May 27, 2024

    Hi @gfraulini,

     

    I wanted to follow up with you on your post to see if your question has been answered. 
    If so, please mark the appropriate reply as the Accepted Solution. 
    Of course, if you have more to share on your issue, please let the Community know so that we can continue to help you. 

     

    Thanks,
    Anurag

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