Running voxl-reset-qvio in mid-flight

[hmlow]

Hi devs

Before i actually test it myself (carefully.....), would anyone be able to advise what is going to happen to the aircraft if it were in Position mode, relying on VIO, and then i force a reset using voxl-reset-qvio:
-when it is moving
-when it is stationary

[hmlow]

Tested it. Wasnt pretty but lucky i had the aircraft tethered.

Just wondering if there are any updates coming along to handle mid-flight resets?

[m1baldwin]

Just thinking about this a bit; if you reset your qvio mid-flight, then you are violating a fundamental rule of an odometric stream, i.e. it must be continuous and differentiable. So, I would not recommend forcing a reset during operation, i.e. flight, as this usually causes the PX4 EKF to reset, and unless you can re-localize you now have a new odometric origin which is random and not tracked.

If you instead want to perform systematic "software refresh" of the qvio - which can make sense if you are landed and resetting the drone, and may be good from a software engineering viewpoint - then that is "less bad". When you need your odometry to work, you should avoid resetting it unless you plan carefully.

[hmlow]

That depends I guess.

If I merely use the drone for indoor navigation purely by tele-oportation (as opposed to waypoint navigation) then I'm guessing resetting qvio mid flight while moving (and causing a shift in the origin of the reference frame) wouldn't really matter.

Unless I'm mistaken, PX4 uses a velocity controller while moving in Position flight mode. Only when it is stationary does PX4 uses it's position controller (and velocity controller) and that's when a reset of the reference frame origin will really screw things up.

Would love to hear from the devs though