Avata 2 Suddenly Lost Throttle Control

[dev_willis]

Hello!
I'm cross-posting this from the DJI forums. There doesn't seem to be an AvataPilots forum so I chose this one.

I just recently bought an Avata 2. I've been flying Inspires and Mavics for years now but this is my first FPV drone. I'm still using the Motion Controller because I haven't bought a real controller yet.

Today, I was flying around the house (it's raining here) for only the second time. I was just taking it easy, learning the ropes. Everything was going well until I flew into my bedroom and over my bed. As soon as it got over my bed, the drone just stopped and started drifting. I was able to turn but it didn't want to move. With the throttle trigger fully engaged I was able to reverse the drift and slowly creep forward. I was trying to fly back out of the room but when I turned toward the door, the drone kept drifting in its original direction. It eventually bumped the wall and kinda stuck there. I couldn't get it off the wall so I tried to just land, which didn't really work. The drone somehow flipped over, fell to the ground, and the props shut off. Thankfully, nothing was damaged.

Can someone help me understand what happened? It wasn't like I lost connection to the drone because I was still getting video feed, I could still turn, and the drone would respond to the throttle but only at full and only barely. I don't think this drone has obstacle avoidance so I don't think there could be an issue related to that. It could well have lost GPS signal in the bedroom but I kinda doubt it had much signal anyways indoors on a rainy day. And surely losing GPS wouldn't cause the drone to become unflyable, would it? I brought the drone out of the bedroom and took off without power cycling and it flew normally again, although I didn't go back in the bedroom. What could have happened? I'm stumped.

Here's an annotated video from the incident:

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Any insight is appreciated!

David

 

[gleavitt513]

I would have originally said the VPS stopped responding due to lack of light in the dark room, which would explain the drifting. But that wouldn't explain the lack of pitch/roll control. With no GPS or VPS, The drone should switch to Attitude mode, which means there is no stable hovering/automatic braking. But yet again, you should have pitch/roll control. My advice would be to try to recreate the situation, and figure out what is going on. Try it with the lights on in the room vs lights off, and in different modes. (sport, normal, maybe manual for full control.)

 

[dev_willis]

I would have originally said the VPS stopped responding due to lack of light in the dark room, which would explain the drifting. But that wouldn't explain the lack of pitch/roll control. With no GPS or VPS, The drone should switch to Attitude mode, which means there is no stable hovering/automatic braking. But yet again, you should have pitch/roll control. My advice would be to try to recreate the situation, and figure out what is going on. Try it with the lights on in the room vs lights off, and in different modes. (sport, normal, maybe manual for full control.)

I think you may be on to something about the VPS. I flew it into the bedroom again with similar lighting a little bit ago and something similar happened. It wasn't as pronounced, but throttle control definitely became sluggish. I don't think I can put it into manual mode while using the Motion Controller but I just bought the FPV Remote Controller 3 and it should be here tomorrow so I'll test it then.

Thanks!

 

[msinger]

Can you share your TXT flight log? You can upload it here.

If needed, you can find instructions for locating your TXT flight logs near the bottom of that page.

 

[GerdS]

The Avata 2 cannot be controlled in Atti mode by the Motion Controller. And in this case there was a quite dark room and no GPS, so the Avata went into Atti mode. I avoid flying both my Avata 2 and Neo indoors with using the Motion Controller and always use the RC3. And for such situations I also have mounted a LED light to the Avata, see https://makerworld.com/en/models/544673.

 

[msinger]

The Avata 2 cannot be controlled in Atti mode by the Motion Controller

Have you come across any official DJI documentation on this issue? It seems like an important mention that should be included in the Avata 2 manual, yet I haven't been able to find any references to it.

I did find it mentioned in several forums, including these:

• Change to ATTI in dark and no GPS
• Avata 2 uncontrollable in ATTI mode with Motion Controller

The Reddit thread recommends using the Firehouse Technology spotlight kit. There may be other kits available, but attaching any kind of light is likely going to require some type of 3D printed mount.

Interestingly, DJI staff responding in the official DJI forum simply advise people to "carefully control" the drone to manage drifting. However, that isn't really feasible if the functionality has been disabled while using the Motion Controller.

Although it's not common for ATTI mode to engage during daytime outdoor flights, it would be a concerning situation if your Avata was high in the sky and drifting uncontrollably, or drifting toward obstacles. This "feature" seems like it could potentially cause more harm than good.

 

[GerdS]

Have you come across any official DJI documentation on this issue?

You're right, DJI should mention this clearly within the manual.
The problem is, that you don't have full control over all three axis and throttle as is required for safe operation in Atti mode and supported by RC3. The idea behind the motion controller is steering a drone which is always aware of its actual position and heading. This is not the case in Atti mode.

 

[dev_willis]

Can you share your TXT flight log? You can upload it here.

If needed, you can find instructions for locating your TXT flight logs near the bottom of that page.

Sorry about the delay. Here's the log: DJI Flight Log Viewer - PhantomHelp.com

I notice there are a LOT of warnings about ambient light being too low and the vision system not being available. The warnings were occurring throughout the entire flight though. I've looked through the logs for other flights as well and every time I've flown indoors there have been hundreds of these warnings but only once have I had this issue so IDK how useful that is.

 

[msinger]

Thanks for sharing!

I don't see any warnings around the area where the incident occurred. At about 80 seconds, the drone abruptly stopped, and the throttle value suddenly shifted to 1024, which corresponds to the center stick position on a standard remote controller, even though you likely didn't stop giving it throttle at that point.

 

[dev_willis]

Thanks for sharing!

I don't see any warnings around the area where the incident occurred. At about 80 seconds, the drone abruptly stopped, and the throttle value suddenly shifted to 1024, which corresponds to the center stick position on a standard remote controller, even though you likely didn't stop giving it throttle at that point.

View attachment 181141

That's a cool graph!