although probably not what you want to hear. I think I’m biting off more than anyone else has ever chewed before: autonomous (self-contained) flight control. I was watching a normal guy’s first flight of his DIY quad. I’ve no idea of it’s build, but the first test flight was in his 4m x 4m lounge (my estimate) full of furniture, and it went better than Phoebe had ever achieved.
Then I started thinking back through all the other YouTube videos of quads in flight, and they all share the same piece that I am missing – an external PID feedback system whether it’s a human with a transmitter or the external monitoring system as shown by Raffaello D’Andrea’s video.
So I started looking at quadcopter PID images on Google, and they show the same thing: they all have an external feedback system (usually a user with an RC transmitter) where I have my velocity PIDs. This is why I’m having so much trouble with drift control: untuned acceleromer integration to produce drift feedback simply cannot work due to offset / gain inaccuracies; for completely autonomous control, the accelerometer tuning with trend lines to incorporate temperature shifts may well be the only solution until drift becomes large enough for GPS to take over.
I think I may have to return to the tedious trend line tuning to get better trends and hence better drift control.
Still, it’s motivationally exciting to think I may be breaking new ground. Shame it’s taken me so long to come to this conclusion.
Here is some motivation for your autonomous quadcopter. As expected, they are using more than accelerometer and gyroscope data. http://www.engadget.com/2014/05/22/project-tango-equipped-drone-wont-be-deterred/
Thanks Jeremy – I’ll be including this amongst others in my next post.