I have a Pixhawk, GPS and 433 MHz telemetry from 3DR ( bought over a year ago), Spektrum DSM2 with DX9, running ArduPLane V3.5.0. I use either Mission Planner or APM Planner2, latest versions.
Airframe is a FunCub but my problem is present even when the electronics are not mounted on the plane.
While in Manual, FBWA or B, Autotune all is well. However, as soon as I’m in Guided or RTL, I get sometimes brief servo movements on my ailerons and rudder ( but not other servos) of sigificant amplitude ( 40 to 60° moves) and the occasional long servo move which evidently resulted in a crash during my test flights.
The graph of Channel 1 ( aileron) RC in and out is below. Elev moves on the RC and tilting the plane have the expected behaviour butwhen all is stationary, you can see the short glitches and a long one.
[attachment=0]PH4 Ch1 glitches.JPG[/attachment]
I have tried:
2 different Pixhawks, 2 different GPS, default plane parameters and my parameters, with or without telemetry, 1 or 2 compases, etc.
When you say
"my problem is present even when the electronics are not mounted on the plane"
what does that mean exactly? Are you saying without the pixhawk you have the problem?
Below is a graph of the signals coming in from the receiver. You can see the spikes. So unless your moving the sticks briefly at those times your receiver/transmitter is providing spikes to the autopilot which isn’t great.
Thanks, Grant.
[quote=“gmorph”]When you say
"my problem is present even when the electronics are not mounted on the plane"
what does that mean exactly? Are you saying without the pixhawk you have the problem?
Below is a graph of the signals coming in from the receiver. You can see the spikes. So unless your moving the sticks briefly at those times your receiver/transmitter is providing spikes to the autopilot which isn’t great.
Thanks, Grant.
[attachment=0]figure_1.png[/attachment][/quote]
I removed the electronics from the plane, and am testing the Pixhawk without the plane.
And yes, all my receiver input is intended - to see how the output follows input.
Channel 1 is normally aileron not elevator. Is that what you meant?
So, as I said previously I think your transmitter/receiver is providing occasional spikes for some reason. At least that’s what the graph says. Is it possible it could be some interference coming through the receiver electronics?
Thanks, Grant.
[quote=“gmorph”]Channel 1 is normally aileron not elevator. Is that what you meant?
So, as I said previously I think your transmitter/receiver is providing occasional spikes for some reason. At least that’s what the graph says. Is it possible it could be some interference coming through the receiver electronics?
Thanks, Grant.[/quote]
my mistake on the graph… its not elev but aileron.
no, I am not getting receiver spikes - thats the first thing I looked at as a possible problem. The radio input is totally clean - when i move aileron on the radio the output tracks perfectly, when i tilt the plane the output is correct but when I do nothing, i get frequent glitches on the aileron.
If you look at the log files, the receiver seems totally clean.
