What does the externalForce matrix Fext represent

I would like to know what the entries of the Nx6 external force matrix (Fext) exactly mean.

I know that Fext represents the Torques/Forces applied to the EEF by an external wrench.

But how would I compute Fext from the wrench on paper?

Thank you for your help!

[Asvin Kumar]

What paper are you talking about? What is Fext? What is EEF?

What have you tried so far? Are you running into any errors?

I'm just asking clarifying questions so that the community can help you better. Your question provides too few details at the moment.

Answer 1

[Karsh Tharyani]

I think you are referring to externalForce's output "fext".

"N" in the N-by-6 is the degrees of freedom of your robot (it is the number of non-fixed joints in "rigidBodyTree" the way it is currently modelled). You can typically associate each row with a corresponding body in the "rigidBodyTree" and the 6 element row vector as the external wrench acting on the body.

Can you state which paper are you referring to?