Odd Flight Behavior with Litchi

[boykintom]

Flying the P4P yesterday morning with Litchi, I noticed some odd behavior during the flight. For the outbound flight, all appeared normal, but shortly after I turned back to the southeast (inbound), I began to notice regular, short intervals of slowing down and speeding up, even though the elevator remained in the same position. Airdata shows 50+ mph wind gusts, but I don't believe that is true, I think the program interpreted the loss of speed as due to wind, but I believe there must have been some other cause. I would like to upload the flight log, but apparently .csv files cannot be uploaded on this forum, since I just tried and got the message that the extension was not allowed. Does anyone know how to do this? A flight a few minutes later with the same craft and a different battery, but flying with Go 4, showed no such anomalies, and maximum wind gusts were only about 8 mph. Thoughts from the group?

 

[Mark The Droner]

Sounds to me like you had an intermittent control signal for whatever reason...

 

[Newt59]

If it happens again, turn around and fly backwards and see if it behaves better. Flying directly into the sun has caused some obstacle avoidance issues for me. The strong UV was faking out the sensors. At least that’s my take on it. Also, try shutting down obstacle avoidance sensors and see what that does for you. Just don’t forget to restore them if you are accustomed to flying with them.

 

[boykintom]

Obstacle avoidance as the culprit never occurred to me, but it really makes good sense as a logical explanation, as the problem didn't start until I turned southeast, more or less directly into the early morning sun. I will try to recreate the flight soon and will turn off obstacle avoidance if I see the same problem then see what happens. If that makes no difference, I'll turn around and see what that does.

Sounds to me like you had an intermittent control signal for whatever reason...

Not according to Airdata, at least not at the points in the flight where this was occurring.

 

[RodPad]

@boykintom

Upload your .csv here.
DJI Flight Log Viewer

Rod

 

[Newt59]

I complained about “starting and starting” to a friend and more experienced pilot. He told me about the UV issue. Just last weekend I was returning to home point into the setting sun and had the issue. Flew backwards with no issues.

 

[boykintom]

@boykintom

Upload your .csv here.
DJI Flight Log Viewer

Rod

I did this, but I was surprised to see that the viewer showed so little of the data as compared to the .csv file itself. It doesn't show the compass heading or the stick parameters, just to name a couple of missing items. Is there a way to choose a more detailed view?

 

[RodPad]

Well yes, if you share your results, copy paste the url of your flight log here.

Rod

 

[boykintom]

While I don't mind sharing my results, I'd also like to use the log viewer to see more details myself. Can you tell me how to do that?

 

[RodPad]

While I don't mind sharing my results, I'd also like to use the log viewer to see more details myself. Can you tell me how to do that?

With out seeing your results, I, we don't know what you see.

Check out this ongoing thread, This was based on a missing Phantom when he finally posted his mission then things started to happen, his data log was not much use because it was to short.

Phantom 3 drone down

Rod

 

[RodPad]

OK, well took a look at this thread..

Professional - P3P drops into sea. Help with flight log

Rod

 

[ftttu]

I have a terrible memory, but I think what may be happening is that you have your cruising speed and your maximum flight speed the same or very close together. If you get a tailwind, which naturally speeds up your bird, it will try to slow down to that max speed you have set in your mission settings. I normally fly at 28 mph during my waypoint missions, but set my maximum speed at or above 35 mph so a problem like yours doesn't happen.

 

[boykintom]

I have a terrible memory, but I think what may be happening is that you have your cruising speed and your maximum flight speed the same or very close together. If you get a tailwind, which naturally speeds up your bird, it will try to slow down to that max speed you have set in your mission settings. I normally fly at 28 mph during my waypoint missions, but set my maximum speed at or above 35 mph so a problem like yours doesn't happen.

Thanks, but that was not the case this time, as I was not flying a waypoint mission but FPV instead. I'm now almost sure that the problem had nothing to do with Litchi, but was caused by flying into the early morning sun with obstacle avoidance on. I tried the same flight at about the same time yesterday morning with obstacle avoidance turned off, and I had no problems. However, as soon as I turned obstacle avoidance back on, still facing the sun, the P4P slowed down and came to a halt, just like it was doing before. So now, I'm about 99% sure that flying into the early morning sun is messing up the sensors, fooling the craft into thinking there is an obstacle. Looking at the details in the .csv file, I see distance numbers showing up for front obstacle distance during those periods of slowing down and stopping, but nowhere else.