First off thank you again to everyone working on this!
After months of set up and bad weather, I was able to get a few flights in today. I had good performance after making small adjustments to NAV ROLL I, Crosstrack Gain & Xtrack entry angle via APM Planner.
Very impressed to say the least!
I'm using an EasyStar with ailerons and a small brushless out runner, definitely not a hot rod but stable and I can get long flight times with a 2800mah Lipo.
While operating in AUTO mode at the prescribed altitude, theoretically if a waypoint is directly upwind and the wind is blowing at 10ms headwind, should the plane not move across the ground since the APM is attempting to maintain 10ms AIRSPEED? I would assume in this example GROUND speed would be zero. I may have missed it but is there a way to enable Airspeed logging in the eeprom log?
Also can someone explain the 1.9 scaling in reference to airspeed?
Thanks again,
Joe
Replies
Yes, you are correct. If you set an airspeed of 10m/s and have a headwind of 10m/s then you will not make forward progress. Be forewarned, our navigation code does not handle this situation well at all. Any time that your ground speed gets very low expect to have severe difficulties with navigation.
Airspeed is logged in EEPROM using the NTUN message. The CTUN and NTUN messages are very helpful for tuning. I use CTUN, NTUN, GPS, PM, MOD, and CMD as my default set.
The 1.9XXX number is a calculated value accounting for the constants in the theoretical equation converting pitot pressure to airspeed, as well as accounting for the sensor sensitivity, supply voltage and ADC resolution.