Hi,
I am trying to use the sonar (Maxbotix LV-EZ0)
As soon as I enable the altitude mode, the quadcopter starts to bounce up and down, won't stay still.
I can see the sonar readings in the mission planner and they seem good (connected to a PC with no battery attached)
Looks very similar to what's on this link:
http://diydrones.com/profiles/blogs/sonar-alt-hold-issue?xg_source=activity
which I haven't tried yet.
My question is... is a sonar indispensable for altitude hold? Can I trust the barometer alone?
Will also try disabling the sonar to see what happens, but I wanted to hear your opinion.
Thanks.
Tono
Replies
The baro hold is very good in the new software 2.91/9.1b.
It will drift slowly with time, but typically no more than a foot in an entire flight time.
Where sonar wins massively, is doing low altitude terrain following.
Sonar gives faster altitude updates, so if your altitude gains are close to oscillating, switching to sonar can trigger oscillation.
Since it also turns it's gain up when a reflection is not seen, it can do silly things like picking up the undercarriage, when you move over areas with poor ultrasonic reflectivity (mossy lawns for example).
Best Wishes