TShiro
 lvl.1
Flight distance : 2538550 ft
United States
Offline
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I think I may have found an idea of what's going on with Air Data regarding the "Not Enough Force / ESC Error" message that has been occurring. I believe Air Data has only recently added this notification in, as people are only seeing it and discussing it now (your post was the first one ever that discussed this exact notification), whereas if it shown up more frequently in the past, there would've likely been a post made about it.
Anyway on to what I think is the answer.
After doing a flight with my iPad's screen recording feature and flying my drone in sport mode (somewhat aggressively), I was able to achieve that message that we are all trying to figure out. Using my screen recording, I crosschecked the time stamp on my recording to the first instance of the "Not Enough Force / ESC Error" notification, this happened at about 1:33 into the flight (As shown in my screenshot). I checked what happened during that time in the screen recording, which showed a "Max Motor Speed" notification at the top of the screen, (blurred for privacy). I am almost certain that the "Not Enough Force" notifications correlate directly with the "Max Motor Speed" message on the DJI app.
I double checked this by checking other instances of the "Not Enough Force" message at different times, all of which displayed "Max Motor Speed"
With that information, I took the .DAT files from my aircraft, and loaded them up in CsView to view other information gathered by the aircraft during that flight. I closely inspected my motor speeds since a maximum motor speed was obviously reached, based on the message from the DJI Go App. I have attached the motor speed graph below. The x-axis is in seconds while the y-axis is in RPM.
Something to note here is that Air Data starts a log everytime the motors on the craft are started while CsView starts a log everytime the aircraft is powered on, so the reasons why my motors start at 121-seconds is because I had a flight previously. To calculate the time difference, you would just subtract 104 - 32 = 88-seconds. Thus, the CsView graph has timestamps that are 88-seconds ahead of the Air Data timestamps, so this needs to be kept in mind.
Anyway, Air Data states that I had a "Not Enough Force" notification at 1:33 or about 93-seconds. Adding 93seconds + 88seconds = 181seconds (give or take a couple seconds since timestamps are not down to the exact second).
Looking at the CsView plot, we can see that around 180-ish seconds, the motors reached a peal speed of 10,057 RPM, hence the "Max Motor Speed Reached" message through the DJI Go app. However, I could not find a consistent speed at which the motors will yield that message, sometimes it displayed at 9300 RPM, other times at 9600 RPM, however, I noticed that the "Not Enough Force" message would only be present when the motors exceeded an RPM of around 9300 or so.
So with all this information, it seems that the ESC is telling the motor to spin faster, however the motors have reached a physical limitation in speed (which could be caused by air density, aerosols within the air which you are flying, or other variances), and cannot spin any faster, therefore throwing an ESC error through Air Data. (it's hard to explain over text)
Using CsView, I was also able to see the Pulse Width Modulation (PWM) Motor information, and how it correlates to the motor speeds, I noticed that extremely high RPM's also directly correlated with PWM values that were >95%.
This above statement may not make sens to everyone, slight research about Pulse Wide Modulations and their connection with ESC's is necessary.
So question to the DJI folks: Is there a definitive number at which a "Max Motor Speed Reached" message will display?
Or will the Max Motor speed vary based on weather condition such as air density, density altitude, pressure, etc?
(I would assume it does)
Overall, with the information I have attached, and the correlations that have been identified, it may not be a physical error, but rather one caused by environmental effects or aircraft limitations. |
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