Hi I'm new to APM, and have recently installed it on a 1720 wingspan pusher propeller plane. Currently it flies fine manually, but I haven't tried any of the auto modes yet. The wiki says xacc and yacc should be kept within -3~3,but I don't know how to tell between vibrations and actual movements.So could someone tell me if my data is ok, and how to distinguish them. Also, please take a look at my mag field and throttle graphs as well. Oh and i remember landing the plane in the middle of this log. Thx.
xacc and yacc values you listed are for multirotors as they are very sensitive to vibrations, perhaps you got the two wiki's mixed up, as I can't find any refrence to vibrations in the APM:Plane wiki.
While it is bad to have vibrations in a plane it won't have the same negative effect as in a multirotor.
As long as you don't have noticeable noise and vibration in the plane I wouldn't lose too much sleep over it. Vibrations on a plane can be checked, if you really want to, on the ground, the plane doesn't have to be in the air, just throttle up and down and look at the log later, you'll be able to see when you throttled up and you want to check the variance between 2-3 peaks and troughs. You can balance your prop if need be to make it as smooth as you can.
Try FBW_A mode first as any problems in an auto mode will show up in FBW_A. Be ready and get used to switching back between modes at any time.
Triple check on the ground in FBW_A that right aileron goes up when you roll the plane left and that elevator goes up when you nose down the plane before testing in the mode, I still do this before every flight.
The part on vibrations is in the diagnosing problems using logs section. I did notice a lot of the plane wiki seems to be directly copy-pasted from the copter wiki. thanks for your advice, I'm still messing with the PID settings to make FBWA feel more comfortable.