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KumarRobotics / kr_mav_control

Code for quadrotor control
BSD 3-Clause "New" or "Revised" License
105 stars 42 forks source link

Should be able to send feed-forward moments in quadrotor_msgs:SO3Command #50

Open justinthomas opened 8 years ago

kartikmohta commented 7 years ago

See d335e018c05069a22f2470ad58aa134aaec5b6ba, we can cherry-pick the commit to master if this is really useful for multiple people.

justinthomas commented 7 years ago

Sweet! This is great, but perhaps we could include snap in the PositionCommand and update so3_control accordingly before fully merging?

kartikmohta commented 7 years ago

So demanding! 😐

justinthomas commented 7 years ago

Sorry :-/ Feel free to merge :-P

kartikmohta commented 7 years ago

Now you've put the snap idea in my head, cannot merge without it 😛

jsvacha commented 7 years ago

What would snap be used to compute? Desired angular accelerations? Is our onboard attitude controller even capable of taking those?

justinthomas commented 7 years ago

@kartikmohta hehe, gotcha!

@jsvacha, yes, angular accelerations. They are required to compute feedforward moments. In the current state, the SO(3) controller doesn't include them but it is a fairly straightforward extension. I'm happy to send some derivations along if that would help.

sytang commented 7 years ago

https://xkcd.com/356/

jsvacha commented 7 years ago

This makes sense. I'd just check the scaling factor on the moments. I made the scaling factor so that the moments would be what I expected to see caused by drag during forward flight, and I'm fairly confident that you want a larger range than that, especially if you want to do flips and such.

justinthomas commented 7 years ago

Ahh, yes. Good point. Since the scaling factor is particular to the hummingbirds, we can determine the full range on the moments, so that should help.