FC: Matek H743-Slim-V4
In Guided or Auto Mode, I set the takeoff to 3 meters relative to home, and at 3 meters, I get the event not_landed, which means takeoff is complete. But for some reason, the drone increases altitude by another 25+ meters. In waypoint_auto.bin, I set the waypoint to have an altitude of 2. You can see that the drone’s takeoff overshoots and then it descends to 2 meters to reach the waypoint.
Do you have any idea what’s going on?
@Leonardthall @rmackay9 Do you have any idea what’s going on?
You have not even attempted to tune your craft - and still tried to fly a managed mode.
All PIDs are at defaults, PID responses look like this (these should not oscillate clearly, especially the proportional part, and should not normally exceed 0.1 when not doing anything crazy):
and motor outputs like this (not clipping from either above or below, should be normally quite similar to each other when hovering, with some noise maybe 100 PWM wide):
so there is nothing to talk about. Tune the machine. Sorry for the burst of anger, but it’s a really bad idea to fly autonomously before completing basic tuning.
You need to set:
ARMING_CHECK,1
plus complete the initial parameters like voltage monitoring and failsafe actions.
The tuning is non-existent and motor outputs are oscillating badly, often hitting minimum PWM.
I think you’ll find the copter is rising in an attempt to maintain stability - throttle has to go to ZERO for the copter to descend.
I would say you need to fit an RC receiver and complete all tuning before revisiting this issue. Once the copter flies perfectly with an RC transmitter and receiver in all situations and failsafes are tested, then proceed with guided-only operation.
EDIT: Maxim replied while I was working on my answer 
I was looking at this too but didn’t see what @MaxBuzz and @xfacta highlighted until after they posted as I was trying to work out why it was climbing further than it should. Thank you both!
This all looks a little strange but the truth is with your current tune you are lucky you didn’t crash.
I am happy to look at this again once you have the aircraft tuned and flying safely.
Thank you for the feedback! I’m restarting from scratch and attempting a flight in stabilize mode. All motors spin in the right direction and all props were mounted in the correct direction.
But every time I increase throttle, the back right motor lags (or doesn’t generate enough lift) and the drone flips. Here’s one example: video and bin file. Here’s another: video and bin file. The back of the drone faces the camera, so the right motor that is visible is motor 4/B and the left visible motor is 2/C. Launching off the LiPo is super unstable and could damage it, so that could be the cause. Another hypothesis is that my ESC isn’t passing enough throttle to the back right motor.
Here are my updated params. What do you think is causing this behavior?
The primary cause, 99% likely, is the default D values for roll and pitch PIDs, 0.0036, which are way too high for this machine in its current state. They do this:
and quickly saturate the entire control bandwidth. For a new agile machine, I would start with a value of about 1/30 of that, say, 0.0001. While this will not give you sharp control, this should get you to something resembling a sensible hover.
(It looks as if someone, maybe me, has to make a video with typical Ardupilot quad behaviours with PIDs radically mistuned in different ways, to aid the initial tuning towards the “basically flyable” (c) state)
This will not be the end, just the beginning, there is a lot of things yet to be configured correctly on this machine, so please post the logs and videos of further tests. Maybe to direct messages, so that we don’t pollute the global blog space.
And one more: With a quad, please don’t try to punch an untuned machine to leave the ground sooner, this most often does not help. It does help with some other designs, but with quads you can start gently, and this approach would save you some time and money on repairs.
@Aidan_Kwok use ArduPilot methodic configurator software to fix this parameter mess in the correct sequence.
