Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Possible bug in models.py #157

Open
OmidRezayof opened this issue Jun 26, 2024 · 2 comments
Open

Possible bug in models.py #157

OmidRezayof opened this issue Jun 26, 2024 · 2 comments

Comments

@OmidRezayof
Copy link

Hi,
Great job with this amazing library!
I wanted to inform you about a possible bug in models.py

J = self.get_global_link_geometric_jacobian(link, q)

        # Transform jacobian to given base link
        R = self.get_global_link_rotation(base_link, q).T
        O = cs.DM.zeros(3, 3)
        K = cs.vertcat(
            cs.horzcat(R, O),
            cs.horzcat(O, R),
        )
        J = K @ J

In line 1340 and when trying to transfer a Jacobian matrix from the world link to a desired link, matrix 'K' (also known as the Adjoint of the Transformation between the world and the desired link) should look something like this:

image

which made me think there might be a bug in the code. If you're using a different logic, please accept my apology and let me know.
Thanks.

@cmower
Copy link
Owner

cmower commented Jun 26, 2024

Hi @OmidRezayof, many thanks for your interest in optas and raising this issue. It is possible there is a bug however I don't remember noticing any issues with this functionality in the past. Have you noticed any incorrect results in any controllers/planners using optas?

@OmidRezayof
Copy link
Author

I have not. I was looking at your library and noticed this typo :)
I'm not sure if we're using the same logic behind this transform but I would encourage you to take another look into it since with my knowledge that might have problems when you actually use it to transform Jacobians from space to another frame.
Just wanted to raise this to your attention.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants