Terrain following problem

Hii every one,

so I updated to version 4.1.3 and I got a new problem. when I switch to auto mode the drone falls like 1m and then going to the mission someone know about this something ? maybe parmters ?

pixhawk 4
4.1.3
with out sensor like range finder.

Send on-board log (*.bin file of the flight, located in SD card).

Do not post in the wrong topic.

https://drive.google.com/file/d/1Ex6OnjpnnlzCo4XKRysp7z7UvJUvURzN/view?usp=sharing
there is a log…

It upends just when I try to do a mission with terrain maps

I need to take a close look at the log file when I’m free.
The first thing I saw is you took off with terrain altitude 30.
Also, your home and origin alt differs by almost 2 meters.
Also, PSC acts like this at the first mission item.

how I can fix this?
I have 2 drones and its the same problem

There is something strange going on with the takeoff command in AC4.1. I also noticed a similar issue, but only when I use the terrain altitude frame. It is probably related to your home and origin altitude differing by 2 meters.

Some home terrain changes just got merged to master. You might want to try that and report back to us?

I did some SITL testing with ArduCopter V4.3.0-dev (0ca48fa9) and the sudden jump problem seems to be fixed, but I noticed another issue. If you have a mission starting with a takeoff command in terrain frame, it doesn´t progress to the next command (waypoint) if the current above home altitude is lower than terrain AGL.

I update again 4.1.3 let’s see if it’s work.

You need to use ArduCopter V4.3.0-dev (0ca48fa9) to test these fixes. ArduCopter 4.1.3 hasn’t this fixes.

I need something stable, I have a few drones…
did you know if there is the same problem with 4.1.0?

Do you really have to take off with terrain alt?
Why not relative alt?
This is only happening during takeoff AFAIK…

Just backport the relevant source code patches from master to whatever version you want to use.
This is not simple, but will get exactly what you want.
Be prepared for a steep learning curve.

Do you really have to take off with terrain alt?
Why not relative alt?

It makes sense if you use the takeoff command to climb to a certain altitude on the spot (after actually taking off and flying around).

Just backport the relevant source code

Already done. Check here for a download link and source code: Sudden jump when switching to auto - #9 by Hoehenarbeit

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I have similar problem. were you able to fix it?

https://discuss.ardupilot.org/t/land-surface-tracking-problem-terrain-agricultural-drone/100845/2

This problem has been fixed with newer firmware.