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$100 to the person who solves this.

Posted by Michael King on May 15, 2013 at 8:44am

I posted this a few days ago.

http://diydrones.com/forum/topics/altitude-loss-in-auto

I am getting a little desperate here.

This application is for US/Mexico Border security. We have a sensor system in place and the hexacopter is launched on alert, with 2.8.1 we were flying great. We upgraded to 2.9.1b and we can't fly auto and it is killing our progress because we are stuck on this darn problem.

I have a background in UAV development specializing in PID tuning so while I am new to the Arducopter APM I am not new to the field. This problem is making me crazy and I need some new eyes to look at it.

This is a real offer.

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Replies

Michael King May 15, 2013 at 7:05pm

I actually just did that. Then we crashed into the shop and lost a LiPo
T3

Richard Boyhan May 15, 2013 at 6:59pm

Also, when all else fails format C. LOL. With regards to the APM, Reset, erase and reload firmware. Be sure to save your parameters and when you reload, use compare and be selective on what parameters you reload. Might not hurt to recalibrate everything while you're at it, radio, ESCs.
Michael King May 15, 2013 at 6:57pm

I am leaning that way rapidly. I just want to be on the same page as everybody else.
T3

Richard Boyhan May 15, 2013 at 6:54pm

If 2.8.1 worked why not use it?
Michael King May 15, 2013 at 6:29pm

Nope, that's not the problem. I can repeat the above probl inside or outside. It screws up in auto and after being in auto.
Manfred Dickgiesser May 15, 2013 at 5:49pm

If you switch to Auto does the quad turn in to a certain heading?

If yes read this

The mysterious AltHold problem .... solved
Michael King May 15, 2013 at 3:01pm
Below are the logs

Here was the test.
1. launch manual - Stabilize
2. Switch to Atlitude hold (Functioned perfect (with sonar))
3. Stabilize
4. Altitude hold - same results
5. Stabilize
6. AUTO- immediate decend
7. Stabilize
8. Altitude hold - Rapid ascend
9. Stabilize - landed copter.
This is very repeatable. If I go into AUTO mode, altitude hold tries to put the copter into orbit.

Any clues here?

2013-05-15 14-47 1.kmz

2013-05-15 14-47 1.log

2013-05-15 14-47 1.log.gpx
Michael King May 15, 2013 at 1:46pm

Here are some flight logs. speed of aircraft was 7 on this flight but has never been a problem before,

In this test I manually launched and turned it over to the APM. The craft flew west descending rapidly. I then took it back and tried to figure out what direction it was facing as th KML file shows.

2013-05-13_17-38_3.kmz

2013-05-13_17-38_3.log
Michael King May 15, 2013 at 1:42pm

This is what happens when a Hexacopter attacks your arm. This happened this morning!
Gary McCray May 15, 2013 at 1:07pm

Just a thought,

You said it flies well in stabilize and alt hold so I have to presume you are trying to fly at least to test this at approximately the same speed you would be flying in auto.

If flying in alt hold is holding the altitude when you try to fly manually at approximately inter-waypoint speed, I don't think that the speed of air movement can be the problem. (If it does descend, then local air movement is the problem).

Assuming it isn't, is it possible that some how your actual waypoint altitude is not set correctly or at least, as you expect.

There is also a waypoint option bitmask that among other things allows altitude to be set relative or absolute, I think it defaults to realtive which is OK but if it is set to absolute that could be a problem.