Simple mission flight

Info and discussion about the original AQ v6 flight controller

Simple mission flight

Postby qalid » Wed Jan 22, 2014 7:03 pm

Hi All,

I want to preform this simple mission within next 1-2 days.. I looked over and couldn't find direct explanation to this..

I don't know the take-off point (which is the same as landing), from the pic attached, how is it possible to program AQ to the following mission, for now:

0; Take-off - could be any point! - simply, its just the point from where I will arm the copter to take-off.
1; WP1 - this point is exactly 25-30 meter (or say even 10 for starting) above the take-off point. No need to go anywhere, just straight up!
2; LoiterTime - is this is the correct waypoint to select if I want to stay at 1, which is on top of 0, for say certain time at certain altitude?
3; Land - come back to the take-off point and dis-arm!

in short, horizontal mission! is it too difficult? Can anyone help on this please?
Thanks
Attachments
Screenshot (13).png
simple mission points
qalid
 
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Re: Simple mission flight

Postby JussiH » Wed Jan 22, 2014 8:24 pm

For what you want to do, you only need 2 mission steps. Takeoff and landing.

If you set a Takeoff command with an altitude of 25m and a loiter time of 20 seconds and a max climb of 2 m/s, the copter will takeoff and climb 25 meter up at 2 m/s and wait there for 20 seconds before going to the next step.

In your case all you then need is to set a landing step with a reasonable descend rate and the copter will come down on the spot and land.

The beauty of this is that you dont even need to set a absolut coordinates, since takeoff and landing commands is relative to crafts current position, so if you want to repeat it at a another position, all you have to do is to move the copter there and repeat the mission.
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Re: Simple mission flight

Postby qalid » Thu Jan 23, 2014 11:17 am

WOW.. this awesome! Sounds even easier than what I thought!

-What is the coordinate frame for the takeoff/land command in this case?
-I assume I will leave x,y and z coordinates as default values?
-Waypoint reaching radius (as in QGC) in meters is 25 m.

And in land command - what would be the max horizontal/vertical speed you think..

Please see attached. Thanks Jussi!
Attachments
2step-mission.jpg
qalid
 
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Re: Simple mission flight

Postby JussiH » Thu Jan 23, 2014 1:02 pm

I use 2 or 3 meter radius in most cases.

Not sure about the coordinate frame. You´ll have to do some trial and error there.

Reasonable landing speeds is ususally 1 to 1.5 m/s.
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Re: Simple mission flight

Postby qalid » Thu Jan 23, 2014 1:25 pm

I thought the radius is the altitude!

The frame coordinate is the fundamental mode I guess! Based on this mode, I will either have radius with/with-out alt. Any idea what's the difference between Local, mission, global abs. alt and global rel. alt??

From what I understand, coordinate frame will determine whether I'm including gps points on the map or not - (in my case, I don't need to)..

Jussi, to make things easier, is it possible if you can share a screen-shot of your mission plan for the video we spoke of (2-step mission video)?

Thanks a lot.
qalid
 
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Re: Simple mission flight

Postby qalid » Mon Jan 27, 2014 12:16 pm

Anyone guys?? I tried with no luck.. Want to know which coordinate (local mission global/rel or abs) to use if I want it to take off from the same location.. NO GPS coordinates! As Jussi suggested..
qalid
 
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Re: Simple mission flight

Postby JussiH » Mon Jan 27, 2014 12:37 pm

Its been a while since I played with this, so I really cant help you more at the moment. The mission planner needs an overhaul, but it has to wait until one of our already hard working coders gets around to it. ;)

Some time back, the hit radius and loiter time was swapped. I dunno if this was ever solved.

I think you can use both absolute or relative. Should not make a difference. I think I used "global/absolute" for all waypoints on the last mission I flew, but I cant remember...

We do mostly inspection work, so thats predominantly DVH flights. Missions I have only used for photogrammetry work (orthophotos), and as I said - its been a while...

You´ll simply have to do some trial and error with it.
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Re: Simple mission flight

Postby qalid » Mon Jan 27, 2014 12:46 pm

Ok Thanks Jussi - just becoming bit over conscious lol

DVH reminded me of another question that I asked you earlier (email), shall I go for 6.7?? Anything that will significantly help with my goals?

The email also reminded me with the videos that I've sent! Have you seen them?
And GPS accuracy as you can see in the 2nd flight video - I'm confused because same PID tuning produced an outstanding stable flight, but then with bad GPS (less warm-up time), the altitude was literally all over the place!! It was gaining and loosing in a very funny fashion!

So what your say on this!? Can you achieve stable locked pos. hold with GPS_HACC >0.8-1 m or it has to be <0.5!?
And how to enhance this? I don't mind buying new/better GPS antenna if that's the problem!?

Thanks buddy!
qalid
 
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Re: Simple mission flight

Postby qalid » Mon Jan 27, 2014 12:51 pm

Here are the logs for this GPS accuracy issue!
viewtopic.php?f=36&t=2890
qalid
 
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Re: Simple mission flight

Postby JussiH » Mon Jan 27, 2014 7:00 pm

Id go for an upgrade to the latest release candidate.

But remember to keep track of which version you are flying now and keep a backup FW and parameter file for it, so you can revert.

The exact FW version will show in the mavlink messages in the communications console on board bootup.

Be aware that PID scaling was changed recently for some values, so you wont be able to directly translate your old setup.

Instead you should scale the affected values by the same factor as in your old setup. So if you had 1350 for Angle D in your old setup thats a roughly 25 percent decrease, so apply that same decrease to the new Angle D default value.

I dont think this was ever added to the wiki, but my only PID copter has not flown for a while, so I cant really help with attitude PID tuning.

Hacc is a vital component to acheive good hold characteristics. >1m is needed for a decent pos hold, but lower will be better. Do note that GPS reception varies as a function of how many sats are visible in your area, so it can vary over the course of a day. Normally you should be able to get down around or under 0.5 on good days.

This tool is quite handy for predicting when GPS signals will be optimal in your area:

http://satpredictor.navcomtech.com/

IMU calibration also comes into play for altitude hold, since vertical acceleration estimation is a part of the altitude estimate along with the GPS and Baro. So if you Z-acc is off, it will affect the systems ability to correctly estimate altitude when GPS signal is poor or not present.

Have you covered the baro with some open-cell foam and shielded it from sunlight? Gusts and sunlight has negative effects on the barometer.
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