EuRoC Forum

[mfaessle]

I was looking over the document "EuRoC_Call4Challengers_TechnicalAnnex_C3.pdf" and stumbled on to something sin section 4.3 "Helicopter Parameters".
There is an equation relating the rotor speeds to the the moments and thrust of the hexrotor. In there it seems to me that there is a mistake (by just looking at the units) in the "diag()" part with the k_n and k_m constants.

According to me, the "diag()" part should be:
diag( [ k_n*L; k_n*L; k_n*k_m; k_n ] )
or
diag( [ k_n*L; k_n*L; k_m; k_n ] )

What is actually used in the simulator?

Thanks

[markusachtelik]

Thanks a lot for spotting this, and sorry for the mistake!

The correct version is diag( [ k_n*L; k_n*L; k_n*k_m; k_n ] ). The simulator does not have this allocation matrix explicitly (gazebo does all the work), but thrust is implemented as n^2*k_n and moment around the rotor's z-axis is implemented as n^2*k_n*k_m .

We will update the technical annex accordingly.