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Old Jan 20, 2013, 10:12 AM
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United States, NJ, Jackson
Joined Aug 2010
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Are all these fly always always involving the GPS addon? I have seen numerous times where mine has acted flaky. Even after switching to ATTI mode the quad still seems to act flaky. When this has occurred, if I physically unplug the GPS unit, normal control resumes. I believe the GPS unit still plays a roll in how the quad reacts, even when not in GPS mode.



Jeff
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Old Jan 20, 2013, 10:44 AM
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United Kingdom, Norwich
Joined Jun 2004
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Quote:
Originally Posted by Wirewolf903 View Post
Anyways here's my unexplained uncontrollable fly away with my Naza. Completed my flight checks and everything was working great. After the crash I tested the system and could not find anything that caused the crash. The battery low volt alarm sounding during strange behavior is crazy to me cause it was a full/fresh 4S Turnigy that I've flown a dozen times with no trouble, and have flown a dozen more times after the crash with no problems..........
........This would explain a gimbal freeze up and me being locked out from controlling it for some time then get back control, then loosing it again. Also you can see the gimbal do the little start up roll twitch it dose every time at start up. You can see this happen just before I gain back control and the Y6 gets back stable flight.
That seems like it could be a low battery voltage....or poor power connection somewhere.....if the alarm went off that would confirm that? and the gimbal resetting 'twitch' sounds like interrupted supply voltage.... I find it's easy to loose track of battery pack state when you have a few and quite possible to fit a low pack and then takeoff.... reminds me of my takeoff with a 30cc glow engine plane after chatting in the pits and forgetting to refuel after the last flight.....didn't get back to the runway then either.
I have also seen poor intercell connections inside assembled intermittant battery packs.
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Old Jan 20, 2013, 01:01 PM
Flying R/C since 1964
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United States, IL, Chicago
Joined Sep 2004
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Originally Posted by u2builder View Post
This runaway stuff makes me wonder if perhaps we should use the radio failsafe programming to set some aileron and/or rudder. That way if some how the Naza failsafe failed to work the radio failsafe would perhaps cause the machine to begin to circle rather than to run away. When the batteries died it would come down. Is there any reason not to do this. If not, what would be best: aileron, rudder or a little of both?
If using RTH, the NAZA ignores these inputs anyway and does its own thing.
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Old Jan 20, 2013, 01:46 PM
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United States, MS, Ridgeland
Joined Feb 2009
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Answering for U2

Quote:
Originally Posted by kallend View Post
If using RTH, the NAZA ignores these inputs anyway and does its own thing.
I was going to let U2 answer, but he must have stepped out....
I think he means that Naza does not recognize failure of the rec/trans communication and go to Failsafe.
But, because the rec has a preset ail and/or rud setting, it will make the airframe circle.
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Old Jan 20, 2013, 03:26 PM
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You would need rudder plus either aileron or elevator to get circling flight. Of course the circles would drift downwind, and you could set throttle to a value that would give a gentle descent. If the Naza is in failsafe none of these settings would do anything, so no harm in it I guess. So long as failsafe is still set correctly on the control mode channel.
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Old Jan 20, 2013, 03:27 PM
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USA, NH, Alstead
Joined Oct 2007
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Quote:
Originally Posted by T J Gilbert View Post
I was going to let U2 answer, but he must have stepped out....
I think he means that Naza does not recognize failure of the rec/trans communication and go to Failsafe.
But, because the rec has a preset ail and/or rud setting, it will make the airframe circle.
Yes, that is what I was thinking. If Naza goes into its proper Failsafe mode no worries. But if somehow it doesn't presumeably because of a setup error, the machine would perhaps circle instead of flying away. Kind of a second level of protection was what I was thinking.

If Naza goes into a failsafe and then screws up it won't help I don't think. I had a runaway when I first got started and tried to use an FM radio and had not figured out how to get failsafe working with my FM Futaba radio. Luckily it ran into trees. If it hadn't it would have been gone.
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Old Jan 20, 2013, 08:08 PM
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Thank you everyone for the very kind words of support. At the moment, I will need to get funds back up slowly to get a replacement QAV because of the investment I've also made on the computer that I also bought to do the video editing, which was quite a sizable one.

Thank you also for the suggestions on the GPS tracking units. I will surely be looking to get one during the next QAV build. A DVR that will record the flight (like the FPV plane guys use) is also another powerful tool for searching for downed craft, which I will also be purchasing one for sure.

I didn't think of getting any of these 2 items before, because like I said, my QAV was going to be solely for AP work and not for flying around for long distances where you can't see the quad using LOS. The QAV was only to be flown LOS (which I was when before it decided to fly off) so it didn't enter my mind to be getting a GPS tracker or a DVR since I thought I'd always know where the quad was in the sky. Big mistake on my part.

For the folks asking what my radio/fpv setup was - was using a 12FG Futaba TX, 6008HS Futaba RX for radio control on 2.4ghz.

FPV gear is on 1.3ghz using the following:

-600TVL Sony Super HAD CCD
-1.3GHz vrx w/SAW Upgrade V3 with 1258 MHz from RMRC - http://www.readymaderc.com/store/ind...oducts_id=1020
-400mW 1300MHz vtx from RMRC - http://www.readymaderc.com/store/ind...roducts_id=915
-IBCrazy Bluebeam cloverleaf RHCP antennas on the vrx and vtx from RMRC - http://www.readymaderc.com/store/ind...roducts_id=552


I do fully agree that I should have had a notch filter on my system. I do also agree that my 2.4 radio control could hav been swamped by the 1.3 fpv system. I did purchase a notch filter already, however it was still in transit as when I originally purchased the notch filter, RMRC mistakenly sent me the wrong one so they sent the replacement to me however I didn't have it yet.

That being said, the question I was hoping to get some help/enlightenment on was why the naza did not go to failsafe if the 2.4 signal was indeed getting swamped by the 1.3. I also am wondering why, even after turning off my radio (which should tell the naza that it has completely lost radio signal) and that it should initiate failsafe and start the RTH procedure.

As I mentioned in the previous post, RTH has already been tested twice, both by loss of signal due to distance and by turning off the radio, both instance were also without a notch filter installed yet - which both instances worked ok, the quad did a 180 and flew back to the takeoff point at speed. (I had a post about that a few pages back when I first had the experience with the failsafe due to loss of signal due to distance). I then tested the RTH by turning off the radio (admittedly with a little prayer first and it worked fine, the quad flew back and started to descend for auto-landing.

To be perfectly honest, since the incident yesterday, I've still been in a state of being dumbstruck. I regularly fly gassers and other EP planes/helis, but if they crash, at least it was due to either pilot or mechanical error (like a servo linkage loose) - and I would at least have some pieces of wood or an engine or a couple of servos here and there to take home and to a post mortem. For this incident though, it kinda bites since I have nothing to take home and investigate. All I could so is speculate. Oh well.
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Old Jan 20, 2013, 08:34 PM
Seattle, WA - USA
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Joined Sep 2003
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Another GPS tracker <$50

http://www.ebay.com/itm/Spy-Live-Rea...#ht_4429wt_907
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Old Jan 20, 2013, 09:01 PM
Preserve our right to FPV !!!!
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United States, CA, Chico
Joined Dec 2010
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That line of trackers is suppose to be quite good, but they put out a Tri band model like that one and a Quad-band unit that (according to the guys over on the FPV forum) is suppose to be quite a bit better reception.

Here's a US supplier of the quad band model..
http://www.amazon.com/Real-Time-Trac.../dp/B0087N8MJS

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Old Jan 20, 2013, 09:11 PM
FPV Racer - N4FPV
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United States, GA, Kennesaw
Joined Sep 2009
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Shaun - my post from the other thread you put this on. Thought it may help on this thread also:

This thing did not fly off because of the naza. It flew off because your gps and Rx were swamped or masked, or cloaked. Your 2.4 rx was swamped at that distance by the 400 mw 1.3 Vtx. Mine did the same thing before I got a notch filter and lowered the Vtx power. Not only on the GPS side did I have a hard time getting solid blinking green and a full set of satellites, but on the control side it would "drift", especially at longer distances. There were times I would give a control input and it wouldn't respond, or it would sometimes respond slowly, and then all of a sudden it would be back. It will draw your ass up in a second.

Concerning why it didn't enter RTH; when your rx got swamped it was not either "on" or "off". It is sort of a pseudo-connection when that cloaking stuff happens, especially when you get some distance. It is like the signal drifts in and out...sort of like going to static instead of a fast, defined blue screen (only analogy I could think of). I don't know the technical terms for that...I can just describe what I've experienced. Your rx was still getting a drifted signal at that distance and it was too far to get the "Radio is OFF Damnit" signal. Now if it wasn't cloaked it would have a CRISP, CLEAN SIGNAL or NO CRISP CLEAN SIGNAL...does that make sense?

I would recommend even dropping the Vtx another 100mw to 300mw. And I would get the GPS high on a post as far away from the vtx as possible, and get a 2.4 notch on your Vtx antenna. You'll lock faster also. That will fix your problem and it will not drift away in the future. That control rx needs a good, clean signal or NO good clean signal so it will RTH. Everything in between is mush and will make it go bye bye.

In fact, do this simple test. Get a green blinking lock on the naza and then take your GPS off the post and start moving it closer to your Vtx. You will see it start going from a blinking green to a blinking red as the gps starts getting cloaked. That is the land of mush and it breaks things. If your Rx resides in this land you will see it work sometimes, drift in and out, never work, ...you get the point. Stay away from the land of mush, or "mushzone"
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Old Jan 21, 2013, 12:58 AM
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Zaragoza (Spain)
Joined Jan 2005
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Quote:
Originally Posted by mark_q View Post
I use one like this on my Naza quad.
One year ago, I lost one tricopter with one KK board, and all the FPV gear, and since then I always have the tracker onboard. I made some modifications, ( remove the case, smaller lipo and a battery indicator)
If you loose the bird,you call the tracker, and it send to you an SMS with the coordinates. You put them in the navigator, and you can find it with a accuracy of two metters.
I use for this an Android aplication, ( GPS test pro) . this program indicates in a stright line where is your bird, and the distance to it. You only have to follow the arrow.

I always carry it onboard.

Félix
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Old Jan 21, 2013, 06:23 AM
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Brasil, CE, Fortaleza
Joined Jun 2011
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Hi, sorry for the loss of Shauntot, but I did too had to use my RTH in my very 1st flight this saturday. After doing all that aluminum shielding on Naza GPS antenna and on my LPF at my video tx I was very confidente, but as soon as I got over 300mt I lost all my video signal and had to hit my RTL, I was sure that it was going to be back because I had a fresh brand new Nano Tech 4S 5000mHa. So after 30sec it was back, after doing a recheck in all my equip I did not find anything wrong so I decided to change my little video antenna for a regular one and I am great that I did that.
For results a had a very good video link with no interference at all, even over 1Km distance as I had prior that shielding.
Still have to work more for my GPS lock, still taking more then 30sec to lock.

Mauro
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Old Jan 21, 2013, 06:45 AM
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USA, NH, Alstead
Joined Oct 2007
4,977 Posts
Quote:
To be perfectly honest, since the incident yesterday, I've still been in a state of being dumbstruck. I regularly fly gassers and other EP planes/helis, but if they crash, at least it was due to either pilot or mechanical error (like a servo linkage loose) - and I would at least have some pieces of wood or an engine or a couple of servos here and there to take home and to a post mortem.
Indeed, this is the thing: when I take a plane there is always a little nagging feeling that I may make some dumb error and crash it; when I take out a multicopter and put the goggles on I wonder if it is the last time I am going to see it and never know the reason why.

In the discussion of "swamping" would this be evident in the strength of an RSSI signal or not? Is 5.8 VTX as subject to "swamping" by the GPS as 2.4? What is a notch filter and what does it do?
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Old Jan 21, 2013, 07:11 AM
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United Kingdom, Norwich
Joined Jun 2004
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Shauntot,
that's a blow,
don't know where you are based, but did it have at least a label giving your address/ Tel. details, and ' Large Reward if found' stickers?
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Old Jan 21, 2013, 07:42 AM
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USA, NH, Alstead
Joined Oct 2007
4,977 Posts
Quote:
400mW 1300MHz vtx from RMRC
Isn't this almost the same frequency as the GPS operates at. Could the the VTX have also messed up the GPS signal so that if it went out of RX range it really didn't know where home was? I don't know anything about this stuff really, but has thought that 1300 vtx maybe wasn't good with GPS. On the other hand, I believe the OP said he had test failsafe and it worked fine previously.

I did experience that "swamping" thing when I first built my quad and was trying to use a 72mhz RX. I did a static range check of the RX before I installed it and it had great range, but then I had a flyaway when I got about 150 feet out (handn't set failsafe in my case). It turned out that either the Naza or the GPS killed the range of the RX. I did not have any vtx at the time.
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