ActiveTrack: How does it handle elevation change?
7364 27 2018-3-29
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HighMesa
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I found a spine ridge out in the desert that is spectacular. I'd like to ride up the trail while using ActiveTrack.

Studying the situation with GE, the trail distance is about 300 feet with a rise of 80 feet with a maximum 30% grade. There are lots of rocks and big cacti to avoid meeting.

So, ActiveTrack will need to increase its altitude in both Profile and Trace mode.

Wait, does it do that?

Analyzing a previous ride with GE, it does not:

Profiles

Profiles

Above: The rider descends, the aircraft stays level in Profile mode

Here is the video:

In this case the video looks good despite the fact that the aircraft stays level while the rider descends the trail. The size of the rider reduces by about half (see thumbnails above), but that's not a big problem. And there were no obstacles to avoid.

Of course, riding uphill is another matter: the aircraft could plow into the ground if it started out at low altitude.

The good news is that Profile and Trace modes allow full manual intervention. So I could have adjusted the flight above.

This was the first time I used ActiveTrack with another rider and I was not even aware of the limitation. Lots to learn.

Anyway, the MA may not have enough onboard memory and compute to handle target elevation changes without assistance.





2018-3-29
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MWitarsa
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As far as I know, only the "Terrain follow" mode automatically changes the height (and only to increase altitude)
2018-3-29
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A CW
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MWitarsa Posted at 2018-3-29 10:05
As far as I know, only the "Terrain follow" mode automatically changes the height (and only to increase altitude)

That's correct and it doesn't decrease altitude as you rightly say
2018-3-29
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B1houdini
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Just the other day we were discussing that same question. If Active track followed the terrain or not.
Was to windy to try so I am glad for the answer.

HighMesa Thanks for asking.
2018-3-29
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B1houdini
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Oops ,
Forgot to say that I enjoyed the video.
2018-3-29
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Wachtberger
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Great video indeed! Being a freestyle trial dirver myself (quad, not motorbike) I can imagine that you had a lot of fun :-)
2018-3-29
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OldFaflyers
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My video is lame compared to yours
2018-3-29
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HighMesa
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B1houdini Posted at 2018-3-29 12:02
Just the other day we were discussing that same question. If Active track followed the terrain or not.
Was to windy to try so I am glad for the answer.

Glad to help, thanks for the feedback, and glad you enjoyed the video
2018-3-29
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HighMesa
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Wachtberger Posted at 2018-3-29 12:12
Great video indeed! Being a freestyle trial dirver myself (quad, not motorbike) I can imagine that you had a lot of fun :-)

Thank you. This really brought home the benefit of a skyline behind the subject in Profile mode, in this case the Pacific.
2018-3-29
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OldFaflyers
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I mean to post my YouTube clip of me riding my bike down the hill. It flew at level flight and lost track of me and went ahead..until I hit RTH
2018-3-30
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OldFaflyers
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Here is the clip..elevation change is gradual, you can see at certain height it stopped and tried locking me again but could not but continued looking.  Then went into hover mode until I hit the rth.

https://youtube.com/watch?t=19s&v=ljdzezsSkDo
2018-3-30
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HighMesa
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OldFaflyers Posted at 2018-3-30 23:44
Here is the clip..elevation change is gradual, you can see at certain height it stopped and tried locking me again but could not but continued looking.  Then went into hover mode until I hit the rth.

https://youtube.com/watch?t=19s&v=ljdzezsSkDo

Yes, it loses you at 1:58

Thanks for sharing!
2018-3-31
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HighMesa
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A CW Posted at 2018-3-29 11:24
That's correct and it doesn't decrease altitude as you rightly say

Yesterday I was out riding and it finally occurred to me that one ActiveTrack mode DOES change altitude!

The Trace mode will follow you UP a hill maintaining distance and thus increasing the aircraft altitude to compensate for elevation gain.

Here is an example, from an Airdata.com KML, showing the flight profile changing by 220 feet over roughly 2000 feet:



This is from the rock slope in this video:

2018-0309_ActiveTrack_Trace_Uphill.JPG
2018-4-6
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A CW
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That's interesting - does it decrease in altitude too?
2018-4-6
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SparksBird
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That is very interesting I mean I guess it would if it is not that steep.  Always thought active track would not and only terrain follow would.  Good data to prove otherwise.  I assume like I said a very gradual increase/decrease it would as it seems.
2018-4-6
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SparksBird
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A CW Posted at 2018-4-6 11:51
That's interesting - does it decrease in altitude too?

Looks like according to the very end of his graph it did.
2018-4-6
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HighMesa
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A CW Posted at 2018-4-6 11:51
That's interesting - does it decrease in altitude too?

Have not tried that yet
2018-4-6
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A CW
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HighMesa Posted at 2018-4-6 11:56
Have not tried that yet

I know terrain follow will adjust its elevation up to a 20% gradient but will not decrease in altitude back down the hill. Will be interesting to see if it decreases in active track on the MA.
2018-4-6
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A CW
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SparksBird Posted at 2018-4-6 11:55
Looks like according to the very end of his graph it did.

Yeah, I noticed that. I'll try it tomorrow on my MPP.
2018-4-6
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Malakai_UK
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This guy is using the spark and it tracks altitude up and downhill.
2018-4-6
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SparksBird
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A CW Posted at 2018-4-6 12:03
Yeah, I noticed that. I'll try it tomorrow on my MPP.

Very cool looking forward to the results and a video if possible
2018-4-6
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maurom82
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wow a good video and good discussion, I'm following it, so interesting.
2018-4-6
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HighMesa
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A CW Posted at 2018-4-6 12:01
I know terrain follow will adjust its elevation up to a 20% gradient but will not decrease in altitude back down the hill. Will be interesting to see if it decreases in active track on the MA.

So I found a mountain bike ride where I descend a trail with the MA following behind.

Can't get to the Airdata.com KML right now but it is pretty clear the rider gets smaller and smaller.

So it appears Trace does not descend to keep a constant distance.
2018-4-6
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A CW
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SparksBird Posted at 2018-4-6 15:27
Very cool looking forward to the results and a video if possible

I only post stills on here as I don't have any video links to social media - I mainly focus on photography but I let you know how it goes for sure.
2018-4-6
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A CW
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HighMesa Posted at 2018-4-6 17:09
So I found a mountain bike ride where I descend a trail with the MA following behind.

Can't get to the Airdata.com KML right now but it is pretty clear the rider gets smaller and smaller.

OK - that makes sense - thanks for posting mate. I'll see what the MPP does later today though I'm aware AT on the MA is more advanced than the MPP
2018-4-6
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naxflight
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On this video, not mine. MA change altitude on Activetrack.
I think MA follow a subjet maintaining the size of subjet selected.

2018-4-7
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A CW
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The MPP does not descend in active track for sure (tested today) but does elevate when following the subject (me walking around a field for 2 minutes LOL) then I resumed flying Great thread.
2018-4-7
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HighMesa
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maurom82 Posted at 2018-4-6 15:36
wow a good video and good discussion, I'm following it, so interesting.

A little more data. I went out to the ridge line and rode it.

As you can see below, Trace starts out very level even though I am going up. It seems to be eyeing the Saguaros nervously. Maybe obstacle avoidance kicked in,



Then it looks like it does two "step functions" up the hill. But when I looked at the video I realized this is not true.

It was 91F and a hot wind had come up, blowing right across the gimbal and making it deflect 45 degrees.

AT bravely reached this point and then the aircraft hovered. I really think without the wind it might have followed me all the way up.



When I got to the top I took control and brought it up to the top in two vertical jumps.

Then I reset Trace, rode back down the ridge and... surprisingly it looks like the aircraft DID adjust altitude downward. This is surprising. I thought we had concluded it does not do this.

This is complex stuff. I had to rewrite the post a couple times as I looked more closely at the data. Still not sure I have the whole sequence right.

2018-4-9
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