Hi, our quadcopter used to fly very stably. However, without any changes, during an autonomous mission, it flipped over right after arming without taking off. After the crash, we replaced the damaged motors and slightly reduced the size of the vehicle. When we resumed test flights, we noticed that in Stabilize mode, it again tried to flip over (positive pitch). However, we do not experience this issue in Loiter or Auto mode. But sometimes, during hover or takeoff in Loiter mode, the quadcopter stays slightly tilted. There is our initial parameters and BIN files:
https://drive.google.com/drive/folders/1oYUCO_cKZRJqHZyoETejCrK8brIb6JtU?usp=sharing
Sounds like an IMU gone bad, I’ve got an old Pixhawk like that.
You can redo the Accel calibration and leave it plugged in to USB and MissionPlanner for extended periods to see if the HUD starts tilting.
You may just need a new flight controller.
I have replaced the Pixhawk before, but the same error persists. As you mentioned, when I connect the Pixhawk to Mission Planner, I do not encounter any issues on the HUD screen or graphs. Autotune has not been set up on the vehicle yet. Could this be the reason? Honestly, I am afraid that if the error is caused by something else, the vehicle might crash during the autotune process.
If you have the same issue on two different FCs then it is most probably a configuration issue.
Are you willing to use ArduPilot methodic configurator software to get it right on the first attempt?
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Did you analysed the reason of this crash?
Did you only checked and changed the motor?
What was the damage of this motor. Maybe this also causes a damage of the ESC. Did you check this?
I tried to create a parameter file with Methodic Configurator. There wasn’t much difference compared to the file I created through Mission Planner.
Yes, we investigated the cause of the crash, but we couldn’t find a definitive reason. Unlike previous flights, we experienced issues with both the RC and telemetry connections during that flight. We suspected that the problem might have been caused by this or that one of the motors had been damaged without us noticing. Unfortunately, we didn’t have the means to perform a thrust test, so we couldn’t test the motors individually. We replaced all the motors that were damaged in the crash. Our motors are Hobbywing X8, so we ended up replacing both the motors and the ESCs. Additionally, to ensure that the motors were not damaged, we swapped motors 1 and 2, as well as motors 3 and 4 (i.e., we exchanged the clockwise-rotating ones among themselves and the counterclockwise-rotating ones among themselves). The vehicle continued to tip over in the same direction (forward).
How many steps of the configurator did you followed? Can you post the resulting files?
Am I right, you changed after the crash nearly everything, the FC, the ESCs and the motors and the behaviour is still unchanged.
So see what is common to all this trials since the crash.
So it looks like the frame itself. As the system can handle this during the “automated” modes it seems to be a kind of “misstrim”
So one point is to run again a full configuration as @amilcarlucas recommended and check the frame for some damages
@Juergen-Fahlbusch I doubt that @clksevvall correctly completed the mandatory minimal configuration.
But we will know better once @clksevvall posts the files.