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opensim-org / opensim-core

SimTK OpenSim C++ libraries and command-line applications, and Java/Python wrapping.
https://opensim.stanford.edu
Apache License 2.0
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building a dynamic walker example: complete file has asymmetric mass properties #3871

Open carmichaelong opened 3 months ago

carmichaelong commented 3 months ago

The mass for the two shanks are different (right = 1 kg, left = 0.1 kg).

If both changed to 0.1 kg, the documentation should be updated too.

aymanhab commented 3 months ago

@MichaelHabib04 Let me know if you need help setting this up and testing

MichaelHabib04 commented 3 months ago

@aymanhab set both shanks to 0.1 kg with this starting config, walker gets almost a half step sl opensim_video.webm

Also, starter code for the walker-building exercise uses the Model method getGroundBody(), which should be replaced with getGround() sl2

Should I try making the walker functional?

nickbianco commented 3 months ago

Should I try making the walker functional?

If you're interested, go for it! I think it would great to have this example functional again.

carmichaelong commented 3 months ago

Thanks @MichaelHabib04! I updated the instructions with getGround() and the masses for the shanks updated.

Agreed that it would be good to see if you could adjust the initial conditions (joint positions and velocities, ramp slope) to make it take a few steps to know if this is possible with the updated shank masses. Now that I think about the exercise more, I think it's good that the completed model out of the box cannot walk very far, and then it's up to the user to update the initial conditions to make it work (even for a few steps only).

MichaelHabib04 commented 3 months ago

Ok, I will work on that.