Weird thing happened to me yesterday......or "ESC Error"

[Barbara]

Got to fly i na gymnasium yesterday with the local RC Aircraft Club yesterday. Different, kinda fun. No GPS, Atti mode forced.

Flying at 3-4 m (15 feet) or so mostly. Demonstrated the forward obstacle avoidance a few times to those interested. Nothing out of the ordinary. Tried Sport mode, too fast for me, walls come up mighty fast.

Back to Normal mode and lets try flying low, say 1 m (2 - 3 ft). As I approach the wall (perpendicular) Sparkie suddenly accelerates, seriously accelerates. Hit the wall, not hard because I got off the sticks. Tried it a few more times at low altitude, same thing. (Didn't hit the wall anymore though). As I get close to the wall the aircraft suddenly accelerates forward.

Checked the logs, snippet below:


Battery low, couldn't try again at higher altitude.....Any ideas?

 

[I B Spectre]

I'm sure others here can better analyze the log data, but I'm curious about the "Not Enough Force/ESC Error" message. ESC, I presume to pertain to Electronic Speed Control that governs the motors, but the "Not Enough Force" thing is foreign to me. The "Compass Error" might have been influenced by the ferrous (iron/steel) in the gymnasium. A miscompare between GPS and magnetic heading (compass) could be expected to generate a compass error. Will be interesting to get more knowledgeable input.

 

[nilanjan118]

I have had the ESC error appear in my logs a couple of times. But the drone never misbehaved in my case like you explained. So I brushed it aside thinking it may be just a minor blip arising in the ESC due to sudden gusts of wind. I will be following this thread to see if anyone else has experienced it.

 

[Haggi]

I would be worried about ESC errors..
I've searched through my 300+ flightlogs, not a single ESC incident.

It could be debris/dust in one of the engines.
It could be a slightly tight prop-axl.
It could be corrosion/water damage on the ESC board.
It could be a corrupt firmware update.
It could be .... bla bla

I would still be worried.
Is'nt it possible to check engines and stuff in DJI Assistant on a computer?

ESC errors has to be something like:
Main computer say to one of the engines "Give me 11024 rpm", esc board report back "I can give you 10500 rpm", which is outside permitted deviation.

 

[Barbara]

Spectre, I agree, the compass errors I believe to have been caused by the metal in the structure of the building. As for the log files, all I got was the "Notifications" info, the Flight Player in the Airdata UAV web site said there was no actual flight data. Again, possibly because I was indoors and had no GPS?

The ESC error might have been when I bumped the wall. The aircraft trying to right itself? One thing I do find curious is the altitude data. I was flying at a constant altitude and it suddenly shows 0.1 meters, even a minus 0.1 meter altitude. Didn't happen, so what gives.

Oh, took Sparkie outside for a quick flight in the backyard this morning. All normal. Proper forward obstacle avoidance behavior, flight data recorded. Did not try a low altitude run at anything.

A theory - the spark uses IR sensors for distance measurement I believe. the gymnasium walls are flat and possibly reflective to IR. As the drone approaches the wall at speed, it is tilted forward. Could the forward IR beam be reflecting off the wall, then the floor and then get picked up by the bottom sensors thus confusing the altitude reading? Just a thought.

 

[RotorWash]

The ESC error might have been when I bumped the wall. The aircraft trying to right itself? One thing I do find curious is the altitude data. I was flying at a constant altitude and it suddenly shows 0.1 meters, even a minus 0.1 meter altitude. Didn't happen, so what gives.

As you surmise, I agree the wall bump was most likely the cause of the ESC error and the reflectivity or even pattern of the floor can throw off the downward sensors and give out altitude readings like you describe.

 

[Barbara]

Guess I'll have to chalk this incident up to "unknown". Got back to the gym last night and tried to replicate the original conditions. No sudden acceleration, regardless what altitude I approached the wall. Obstacle avoidance kicked in as expected and stopped the bird short of a collision.?