I armed the copter in POS hold and gave it throttle to take off. It immediately started flying away banking left. It went into LAND flight mode but was still gaining altitude and flying away before actually landing. I would like to know what went wrong so i can prevent this in the future.
https://drive.google.com/drive/folders/1LjoGF7cQn8j0qfZ7FGg2k8BvkKy49H_4?usp=sharing
Has this copter been tuned?
Default parameters. Vibration compensation was activated, not necessarily from vibration. Hope no one was hurt with this craft that should not have left the ground in this state of tune.
Pretty exciting flight! I find your Magnetometer traces curious. You might take a look at Mag0 and Mag1. Is your GPS on in the same direction as the autopilot? Did you calibrate your magnetometer? Given the wild roll and pitch early in the flight and the settled behavior as the flight progressed, I would think itâs the navigation and not the control. So, I would redo the calibration, especially the mags. Iâm curious to know how you resolve this.
You should start by flying in âStabilizeâ mode to handle any emergencies.
If the copter behaves strangely due to GPS issues, take manual control immediately instead of letting it drift away.
Use ArduPilot Methodic Configurator to configure the vehicle. Start at the beginning and do not skip any step.
Users that follow all the steps by the letter get great working vehicles very fast.
Users that do not get vehicles that sometimes behave like yours.
I was gonna do autotune with that exact flight but it took off before i had the chance. I did 3 flights in stabilize beforehand. Flight was really shaky but it didnât fly away.
Again, start at the very begining and follow the steps. Your vehicle will work fine once you do it.
Whether or not youâve completed 3 stabilized flights isnât the main point.
Please carefully consider what Iâm saying.
In any emergency, always switch to AltHold or Stabilize mode, as I mentioned in my previous post.
Even with a well-tuned copter, factors like physical GPS signal loss due to vibration (which Iâve experienced with a large hexacopter) or other unexpected issues can create dangerous situations.
Truth_T - I have taken to relying on Alt-hold mode as âbackupâ. With the EK3 nominally primary set to BARO, I have assumed that this will remove the difficulties of a bad nav solution (from a bad magnetometer or other sensor problem) and leave me without the task of controlling the altitude. Flying in stabilize mode keeps attitude stable, but I have found the âleadâ that I must input to control altitude difficult - especially if you have other problems to deal with. Any thoughts?
Also, Rasmus, I see that the mag messages show realignment after an âAnomalyâ right after lift-off, followed by EKF3 lane switches, and then an IMU0 and IMU1 emergency reset right after the switch to Land mode. Sure looks like a magnetometer calibration problem.
I have no difficulty controlling the âStabilizeâ mode. If youâre having trouble with modes like this, you might need more practice. (Most beginners here struggle with controlling in multiple directions and modes.)
Stabilize mode reduces risk because when you lower the throttle, the prop almost turns off. In Altitude Hold mode, if the copter flips upside down, the blades can spin even faster. While the disarm button serves the same purpose, engaging Stabilize mode is simpler. You can also check your copterâs weight-thrust ratio through throttle engagement, allowing you to âfeelâ the copter.
In older flight controllers, vibrations could cause the copter to shoot up due to z-axis estimation problems, but this doesnât happen in Stabilize mode.
If youâve flown a VTOL, youâll find that Stabilize mode is excellent for fast takeoffs, landings, and moving platforms. Youâll notice that QStabilize landings are ten times faster than QLoiter mode, which helps conserve battery life. The people I know who develop flight controllers all have excellent control skills, especially with Stabilize mode.
If you feel the need to rely on Altitude Hold mode (or feel âleadâ to use it), it might suggest you are less experienced or a beginner.
In this case, the post author mentioned that he has already flown in Stabilize mode, so I donât think itâs an issue for him.