Adding the drakeSimulator class and a working example of drake_walking.ipynb

[akhilsathuluri]

This is a draft PR for the newly added class which are bindings of CoMoDo with drake and an example showing how it works.
The class follows almost exactly the same design of the mujocoSimulator class.
I also added a helper class that bridges between any one coming from a different platform to make their URDFs compatible with drake and simplifies loading. However, this needs the odio_urdf from my repo: https://github.com/akhilsathuluri/odio_urdf and some additional dependencies, which needs to be handled seperately.

For the sake of a common structure, I added the example in Jupyter too, but it is not comfortable to maintain it (especially when the JSON fails due to git merge issues). An alternative is: https://github.com/mwouts/jupytext

In the next push, I will have modified include files to add the angular_momentum and contact_force_regularisation tasks sclaed by robots mass.
(I changed the includes for faster prototyping.)
I have observed the same things as you mentioned today, that the robot falls down after a couple of steps in mujoco too.

[traversaro]

However, this needs the odio_urdf from my repo: https://github.com/akhilsathuluri/odio_urdf and some additional dependencies, which needs to be handled seperately.

As odio_urdf mantainer are not replying, could we do a friendly fork of it called amo_urdf (the italian joke, "odio" means "I hate", "amo" I love) so that we can depend on it without problems?

[akhilsathuluri]

However, this needs the odio_urdf from my repo: https://github.com/akhilsathuluri/odio_urdf and some additional dependencies, which needs to be handled seperately.

As odio_urdf mantainer are not replying, could we do a friendly fork of it called amo_urdf (the italian joke, "odio" means "I hate", "amo" I love) so that we can depend on it without problems?

@traversaro, please let me know what to do about this.

[CarlottaSartore]

I tested also on my machine and everything works fine ! Thank you really much @akhilsathuluri for the PR !
Few comments needs to be addressed before merging, I would also ask you if you can generally clean up the code from comments that do not document the code, and open issues if there is anything you would like to implement in the future or features you would like to have in comodo ! Thanks

[traversaro]

However, this needs the odio_urdf from my repo: https://github.com/akhilsathuluri/odio_urdf and some additional dependencies, which needs to be handled seperately.

As odio_urdf mantainer are not replying, could we do a friendly fork of it called amo_urdf (the italian joke, "odio" means "I hate", "amo" I love) so that we can depend on it without problems?

Ok, in the end we did this, currently private repo available at https://github.com/ami-iit/amo-urdf .

fyi @akhilsathuluri @DanielePucci

[akhilsathuluri]

@CarlottaSartore : I modified some of the methods based on the comments. Do have a look and let me know.

[CarlottaSartore]

Ciao @akhilsathuluri , Thank you, and sorry for the delay.

Most of the comments have been implemented! I would kindly ask you to address this comment on the hardcoded feet collision, before merging!
If you can add some reference also for the other hardcoded values it will be great! Thanks!

[akhilsathuluri]

Hello @CarlottaSartore, here are the changes:

• removed hardcoded feet collisions (x and y values for the boxes)
• added argument names for collision properties (foot/ground dissipation and stiffness)
• Added comments for other hardcoded numbers (RGBA values for visual and collision meshes for the ground plane)

Please let me know if you think more changes are necessary. Also, apologies for the delay 😅

[CarlottaSartore]

Everything looks in place, thanks for your contribution @akhilsathuluri :)