Servers by jDrones

'EKF Primary changed' in-flight ... Is this a problem?

(dave flood) #1

Hi guys. This is my first ever post on a forum.

I have a hex running a pixhawk (with latest firmware).

I have been getting quite a few EKF Primary changed messages occurring while I’m in the air (Err.EKF_Primary-1 & Err.EKF_Primary-0 in the log) I don’t know if this is normal or an indication of something sinister brewing. I can’t find much info online.

A week ago I got a lot of these in a flight and seemed to partially lose control of my drone. I was also getting ‘Inconsistent compass’ warnings on the ground prior to the flight so assuming the two were related I re-calibrated my accelerometers & compasses.

I flew again this weekend albeit on a very windy day. The inconsistent compasses issue has gone but I still got a few ‘EKF Primary changed’ messages. Could wind gusts be causing these latest EKF messages?

I’ve attached the log file from my latest flight if anyone has a moment to look.

2017-03-04 14-03-51.bin (4.3 MB)

Thanks. Dave

(ranqingfa) #2

Got this problem too, there is 2nd GPS in my quadcopter, I dont know if this is caused by the switching of GPSs

(Ash) #3

Hey There, I saw the same message as I’m analyzing a BAD crash.
Below is the plot of NKF5.HAGL, NKF5.rng and RFND.DIST1 plots. HAGL is the “estimated height above ground level (m).” The other two are range finder data.
As you can see the error occurred as the HAGL spiked and the drone crashed. the NKF5.rng and RFND.DIST1 have both spiked before but did not cause any reaction by the drone.
Prior to that, the drone was hovering at wasite height using optical flow and sonar. As I gave a pitch input, the drone dashed forward, smashed into the ground and then dragged itself into a wall. Very exciting.
I’m still analyzing the log, but this looked like a problem.
Anyone else with the same experience? Is this a known bug? How do you avoid it?