First drone build and newbie drone pilot. Relying heavily on Claude for assistance (with quite a few mistakes from him/it), it’s been a fun journey but finally hit bit of a brick wall.
Frame: TBS Source One V5 deadcat, QuadX
FC: Matek H743-SLIM V4
Firmware: ArduCopter 4.6.3
ESC: iFlight BLITZ E55 4-in-1
Motors: ECO 2807 1300KV, 7" props
Battery: DOGCOM 5000mAh 6S Li-ion
Receiver: ExpressLRS on Serial7 (CRSF)
GPS/compass: Holybro Micro M10
I established a stable Stabilize hover at ~6.7m with throttle stick at 1099 (well below AltHold/Loiter deadband center). I switched to Loiter with the stick still at 1099. What happened next:
CTUN.DAlt captured at 7.61m
Within 1 second, DAlt jumped to 8.09m and began climbing rapidly
Aircraft climbed from 6.68m to 48.80m in ~8.5 seconds
My throttle stick was at 991-994 (absolute minimum) for the entire climb
Motors averaged 1200-1330µs (hover throttle)
Only recovered when I engaged RTL
This is not the first time this has happened. Multiple flights show the same pattern: mode change from Stabilize into an altitude-controlling mode (AltHold or Loiter) results in DAlt rising above current altitude and the aircraft chasing it regardless of throttle stick position. I have already increased EK3_ALT_M_NSE and EK3_GND_EFF_DZ to protect against baro spikes, but the behavior persists even at healthy altitude (not close to ground).
Am I missing something obvious in configuration? Is this a known behavior with a specific fix?
things that maybe relevant are that it is part built and there is a camera, gimbal and some more electronics to go on it so it is currently quite light and I am using the 5000mah battery as a weight rather than test with something smaller as initial flights struggled with the quad wanting to hover at almost minimum thrust.
another I have noticed that seems like it could be very relevant is that MOT_THST_HOVER doesn’t seem to be learning (I haven’t had many successful hovers but it should have learnt by now). The interesting thing I have just noticed is that on Claude’s advice I manually set this to .25 and have checked that this setting survives a reboot (and power down). but it seems to reset to .125 after a flight (need to do a short test flight to confirm (I have seen it reset on at least three occasions though) but I live in a no fly zone and cant get out to test for a while).
any help or ideas to diagnose appreciated. Thank You
Did you at some point configured the altitude controller?
From your description you never correctly learned the hover thrust and you have a high powered vehicle, so you need to learn it manually.
Claude will not help you, it has not enough training on how to configure ArduPilot vehicles. But following the steps of the ArduPilot methodic configurator software will. It will fix that issue and other issues you have not encountered yet.
Typical with default parameters. Massive output oscillation. Claude didn’t tell you that? Didn’t think so. Not even the Initial Tuning Parameters set. This craft was not ready to leave the ground.
I have done Avery brief test and it appears OK now.
I have another issue where I can’t get telemetry from my Blitz E55 4-in-1 ESC though so sorting that out is my current priority. I’ll get back to the configurator when I can get past that roadblock
No serial telemetry on that ESC so it will have to be Bdshot. You are not using the Bdshot firmware on the Flight Controller. And of course the ESC firmware has to support it. Old Blheli_32, AM32 or if it’s BLHeli_s flash Bluejay to it.
The SERVO parameters in the log you posted is misconfigured in any case.
The configurator has vehicle templates of correctly configured BDshot systems.
Use them as inspiration: Create a new vehicle directory based on one of them, then compare the contents of that vehicle directory with the contents of your vehicle directory.
The more people that use claude, the dumber it gets lol.
@Paul_Sanderson regarding the 0.125 MOT_THST_HOVER. If I recall correctly that’s the bare minimum ardupilot allows. So your value does seem to be learning but its just learning the floor and not the true value. I have some overpowered 5" that have the same issue, but I do not have the symptom you’re experiencing.
So, I agree with the other input. I haven’t even looked at your log, I just see that there’s a lot of upfront work to do before worrying about the altitude hold symptom. Whether you use methodic configurator or not, the documentation does provide a workflow. I eventually learned enough to be dangerous by reading through the documentation on the ardupilot project site. Though, admittedly, it took me many many tries before learning anything.
These are redundant if the Motor Type is set and BLH_AUTO, 1 is used. And if you have since installed the Bdshot version of firmware, the BDshot mask parameter for the Motor outputs.
SERVO_BLH_MASK,15
SERVO_BLH_OTYPE,6
