Hi Mr. "Walker"
Sorry it took me so long to post this, I had to go to the doctor to get some antibiotics to kick this sinus infection in the butt.
As I was starting to make some sense out of the third example in the first post you made with the graphs when I ran across something else that caught my attention pretty hard (that part was in the .csv files you posted).
But first, in that third example where the Phantom inverted in flight, the motor load going low at the same point as the spikes made sense because the motor commands had made some large dips at that same point. But, those dips weren't present in the acceleration graph that was just above the graph with motor load, motor speed and motor command.
The acceleration spikes would only make sense if the wind was gusty enough to cause them and even then it's questionable. Maybe it was sheer coincidence that the spikes lined up like that.
The motor speed didn't jump enough to cause such sharp and brief spikes like that. I mean we're looking at very small fractions of a second. According to the .csv files, it was fairly windy but I didn't notice anything that would suggest that there were turbulent gusts of wind present.
The following observations make me wonder if the data is reliable.
I was doing some simple page by page comparisons when I noticed that the Phantom was powered up almost 5 1/2 minutes before the motors were started. I began to look for signs that the GPS had been calibrated and found that it had been calibrated (by studying the amount that the compass had turned and the amount that it had rotated on various axis).
I saw where a CSC had been performed by the controller and that was verified by the motor command signals, the motor speed and the fact that the flight clock started at "0" at that point. All seemed to be fairly normal so far.
It used to be that after a compass calibration, we were supposed to cycle the power off and back on again before takeoff but according to the manual, that's not the case anymore (That seems to only apply to my S800 and S1000, I don't know about others).
Have a look at this screenshot:
Sorry, I wrote CSC Command, duh, the last C in CSC stands for command, it was a senior moment and I didn't feel like taking the time to go back and change it. Lol
Then, 6 seconds later the motors were shut down by lowering the throttle stick all the way to the bottom.
I'm not sure why the motors were shut down just 6 seconds after they were started but according to the .csv file, they were.
All still seemed fairly normal though.
Have a look at this next screenshot:
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Now, "THIS" is where things get really weird or strange or alarming or however you would like to describe it.
When I scrolled down to find when the motors were started again, I noticed right away that the motors did start (according to the .csv file) but "Without" "ANY" input signals from the remote control.
The motor commands were there but no command from the remote control, no CSC, nothing..........it was 6 seconds after they were shut down the first time (it took 1 second for the CSC to cycle).
Checkout this next screenshot!!!
This would mean that the motors actually started by themselves "IF" the .csv file is correct.
This sort of thing is what makes me wonder if and when the .dat files and the subsequent .csv files are correct.
You say this Phantom went inverted and flew into the ground. Did the files become corrupt as a result of the crash, or........was there something seriously wrong with the flight system before the crash and was the "cause" of the crash to begin with. If the FC or whatever was already faulty, isn't it possible that the data is wrong as a direct result of the faulty FC or other component??
The flight was just over 14 minutes and I didn't notice the motors slow down any again until the last couple of seconds of the flight, then they slowed down from an average of 4500 rpm to around 1300 rpm.
The voltage at the end of the flight was still 14.5 volts (average of 3.64 volts per cell)
The motors starting with no control signal (CSC) from the remote is a real mystery to me (if they actually did start without performing a CSC). Maybe a CSC was performed to start the motors but the .csv file doesn't show it?
Many of the other numbers indicated a fairly normal flight in windy conditions but there were a few that indicated serious problems, either there were real problems with the Phantom, or a problem with the files.........or both?
Am I missing something here??
I just can't help but believe that there were some serious issues with both the Phantom and the files but that's just my take on it.
Anyone care to shed more light on this one? I've been through it a few times and I keep coming up with the same conclusion.
Thanks!
Joe
