simmechanics simulation seem to slow, like if subject to friction.

Dear all,

I am trying to model a triple pendulum with simmechanics. The solution I obtain doesn't coincide with the simulation I have done on matlab. Actually, the simmechanics model seems to moove to slowly, as if it was damped. I didn't put any friction so I don't understand why it behaves like that. I attached the simulink file. Does anyone know what the problem is'

Thanks a lot in advance.

Answer 1

[Steve Miller]

I looked at your model. It is nicely built, and you made good use of masks. Without the MATLAB Code, we cannot see the difference. Looking at the dynamics, it is clear that there is no damping whatsoever, for the pendulum does not seem to lose energy.

I am pretty certain the reason your models are different is because you entered values of centimeters in your masks, but the Simscape Multibody blocks (Solid blocks, Rigid Transform blocks) are set to meters. I have made the units consistent and the model behavior is much different now. The adjusted model is attached (TripleInvertedPendulum_fixed_centimeters.mdl).

--Steve