[Scilab-users] Bicycle Dynamics

[Dang, Christophe]

Hello, 

> De : De la part de Gona
> Envoyé : mardi 13 mai 2014 13:30
>
> I was referring to this wiki article from the beginning. 
> http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics

OK, that clarifies a bit.
I guess we can trust the Wikipedians (and have no time to make the calculation myself).

> That is true for the rotational equilibrium.

Yes, I thought about it just after clicking "send", we are here in dynamics.

> In the second picture what I have shown is the impulse response of the 
> system ( The out put theta to the impulse input delta)

OK.

I just wonder what you call l.

If it is the height of the center of gravity when the bike is upright, then it is not the length that is in the moment of inertia. Your bike+biker is not a uniform rod.

You may define a radius of gyration for the body about its center of gravity, then apply the Huygens-Steiner theorem where we find l.

But this is rather complicated as you don't have the radius of gyration. You might keep I as a parameter itself.
But this is just a proportional factor and should not have a qualitative influence.

Then: when you calculate the torque of the forces, it seems to me it should be
mg*l*cos(theta) - (mv^2/r)*l*sin(theta)
and not the contrary.

Or?

-- 
Christophe Dang Ngoc Chan
Mechanical calculation engineer

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