Copter 4.7.0b7 - Strange behaviour in PosHold-Mode (solved with 4.7.0b8)

ArduCopter Copter 4.7
1

Hello

I tried today 4.7.0b7 and identified a strange behaviour in PosHold-Mode. When I push the stick in a position the copter first moves quickly into that direction but immediately levels itself and then starts finally to move into the desired direction. I moved back to firmware 4.6.3 with the same parameters and the behaviour is “normal”.

BR

Harald

2

Why use Position Hold anyway? It was superseded by Loiter years ago. It gives you 7 parameters to configure how you like it.

3

Hi Dave

I prefer the PosHold Mode. Would be great to restore it in 4.7 how it was working in 4.6.3

BR

Harald

4

Hi @Harald,

Thanks for the testing and reporting back. There should be any significant changes to PosHold between 4.6 and 4.7.

TBH, I don’t understand the report. In particular the difference between “that direction” and “desired direction”.

When I push the stick in a position the copter first moves quickly into that direction but immediately levels itself and then starts finally to move into the desired direction

I gave PosHold a test in SITL and it seems fine. Perhaps if you could provide some clarification and/or and onboard log file that would be great.

5

I push the stick slightly into forward direction, the drone starts to move forward. After 500ms it levels again (stops moving forward) shortly and then afterwards starts to move forward constantly.

This behaviour I do not have with the same parameters on 4.6.3

I can make a video to clarify but fot that I need to reinstall b7.

6

Hi @Harald,

thanks for the clarification. An onboard log would be really helpful too, even more important than the video is a log.

7

I have reproduced this behavior in SITL and opened a GitHub issue for it here:

Copter: PosHold desired attitude briefly reverses during sustained roll or pitch input · Issue #33588 · ArduPilot/ardupilot

It includes SITL reproduction steps, current master vs Copter-4.6.3 comparison plots, and logs.

8

Hi

Your description is exactly what I observed in real flight. I am excited how you could reproduce it in simulation. Is there somewhere a good description how a newbie like me can also use the simulation?

Br

Harald

9

@zbr3550,

Nicely done! I’ll have a look, txs!

10

OK, I’ve reproduced the issue in SITL and it appears that it was caused by this PR https://github.com/ArduPilot/ardupilot/pull/30358

before-vs-after-pitch
before-vs-after-pitch1204×1146 74 KB

I’ll talk to @Leonardthall and I’m sure we can get it resolved soon possibly using @zbr3550’s PR. Txs!

11

Thanks for narrowing the regression down to PR #30358. I’m happy to help with any further debugging or SITL testing, and to update my PR as needed.

12

Hi @Harald,
You can find a helpful guide on the official ArduPilot documentation. It covers everything you need to get started with the SITL simulator:

https://ardupilot.org/dev/docs/sitl-simulator-software-in-the-loop.html

Hope this helps

13

thank to all because I also use poshold for precision movement, I havn’t tried 4.7 but I love Poshold when I will pass to 4.7, I use loiter for more speed and uniform forward flight like waypoint automatic but in manual, but poshold is essential in wind condition and precision movement; excuse for bad english

14

Hello to the developers

I tested 4.7.0b8 and the problem is solved. Thanks very much for the great work.

BR

Harald