Bendesarts

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These are replies submitted by Bendesarts

That's interesting.

However, i would like to have dynamic equations from the model expressed as a DAE because the choice of coordinates have been "absolute coordinates".

In fact, i would like to have in a symbolic form the DAE equations which are for the planar pendulum theses equations :

Similary to your method, I try to use commands for dynamics : GetDynEQs() or GetSysEQs(). But, with these commands, it seems that no option like with "GetFrameMotion" exist to ask to have the result with "absolute coordinates". So, i'm afraid that maybe it isn't so easy to obtain the dynamic equations with "absolute coordinates". It's a pity because many books dealing with "Multibody dynamics" used absolute coordinates in their formalism.

Thank you for your help.

 

 

OK.

I have check the help section you told me but unfortunately, i found nothing about that.

msim_whitepaper.pdf

I don't find any model or comment on that subject (modeling system with absolute coordinates with maplesim) except this pdf.

In this pdf, they explain that MapleSim can deal with DAE which is very good and thet explain also that DAE can come very quickly. They give the example of a planar pendulum which gives DAE if it is modeled with "absolute coordinates".

So, it is very interesting and gives me hopes. However, i would like know how i can model a system with absolute coordinates ?

Thank your help.

OK.

I have check the help section you told me but unfortunately, i found nothing about that.

msim_whitepaper.pdf

I don't find any model or comment on that subject (modeling system with absolute coordinates with maplesim) except this pdf.

In this pdf, they explain that MapleSim can deal with DAE which is very good and thet explain also that DAE can come very quickly. They give the example of a planar pendulum which gives DAE if it is modeled with "absolute coordinates".

So, it is very interesting and gives me hopes. However, i would like know how i can model a system with absolute coordinates ?

Thank your help.

It's good.

In fact, i should define the parameters before in main subsystem defauft settings and after i can use the parameters.

Thanks for your help

It's good.

In fact, i should define the parameters before in main subsystem defauft settings and after i can use the parameters.

Thanks for your help

To complete my last question, in fact, in the section "Parameter and Variable Manipulation (optional)", i don't see for example the parameters of mass of the different bodies of the slidercrank mechanism

I still do not have an answer!!!

Thank you for your help.

OK. Thank you for your help.
But there is always a issue of values!!! 
The values with the different methods are still different.

Here the calculation

You perfectly answer to my question. Great!
However, how do you find this code ? Indeed, i haven't see this code anywhere in the help section.
Thank you for your help.

You perfectly answer to my question. Great!
However, how do you find this code ? Indeed, i haven't see this code anywhere in the help section.
Thank you for your help.

Here the detail of the equation eq1pp

eq1pp := R(t) = -(-sin(theta[0]+phi)*Isup-sin(theta[0]+phi)*L[fixe]^2*M[fixe]-sin(theta[0]+phi)*L[r]^2*M[r]-sin(theta[0]+phi)*L[sup]^2*M[sup]+cos(theta[0]+phi)*a*sin(phi)*L[fixe]*M[fixe]+cos(theta[0]+phi)*a*sin(phi)*L[r]*M[r]+cos(theta[0]+phi)*a*sin(phi)*L[sup]*M[sup])*(diff(theta(t), t, t))/(a*sin(phi))+Ctheta*sin(theta[0]+phi)*(diff(theta(t), t))/(a*sin(phi))+Ktheta*theta(t)*sin(theta[0]+phi)/(a*sin(phi));

Thank you for you help

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