HI everyone,
I am using an APM2.5 with ArduCopter3.X. I am controlling the copter with my laptop keyboard using a 3DR radio telemetry, MAVproxy and a DroneAPI code.
Every thing used to work fine, until the last test: normally I control my copter in LOITER mode, and I have noticed that the drone will start taking off when throttle reaches 1550 (this seems to be logic), but troubles started last time when I was increasing the throttle and the drone took off strangely at Throttle=1150!!!!
So I removed the propellers and retested with MAVproxy commands:
-----------------
rc 3 1050
mode loiter
arm throttle
rc 3 1150
rc 3 1200
rc 3 1400
rc 3 1500
rc 3 1580
disarm
--------------------
I have repeated this test several times but the results were extremely random:
the motors speed increases at 1150 or 1500 randomly!! I can't not figure out why this is happening!
I reloaded a verified param file and got the same results.
Can anyone tell me please why this is happening, and how to correct it.
Thank you,
Safwen
Replies
Takeoff and hover issues tend to happen when not taking-off in "STABILIZE" mode. There are a couple commands that set the throttle mid-point based on copter weight (either manually or automatically).
TRIM_THROTTLE will automatically calculate the hover mid-point when starting flight in "STABILIZE" mode (that's why it's recommended to do so).
The other way to set throttle mid-point is through the THR_MID setting. However, to determine this setting you must perform a hover in "STABILIZE" mode, then review your log file to see what the throttle percentage was to maintain a hover, then input this data to THR_MID. When this setting is wrong, you will get really crazy throttle response in "non-stabilize" flight modes. And if your copter weight changes, and you don't either first fly in STABILIZE mode, or don't have the right THR_MID setting, your throttle response will be wacky too. I found this out through trial and error (and a couple erratic flights). Now my Pix flies as nice as my NAZA.
See this link for more info:
http://copter.ardupilot.com/wiki/ac_throttlemid/