Quanum Nova FlyAway, LOST :(

Log Analysis -- deprecated Copter Logs -- deprecated
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[attachment=0]2014-11-13 09-49-54.tlog[/attachment]

Looking for some help understanding what might have happened.

We were helping a class with a area protection scenario red team/blue team exercise. Blue team had air assets with live telemetry & Video.

So we were conducting a simulation for our students and were using 2 quanum Nova quads with gimble, GoPro3+, 3DR radio, 600mw TS832 for video, 3000mah 3s battery. We also had a SkyEye with pixhawk, not in the air at the time.

We had 2 ground stations running, one Nova (Kestrel) was using 3dr with a net ID of 45, and a second Nova (Peregrine) was using a net ID of 30. The SkyEye (Condor) was using a net ID of 25 but was not powered up during the incident.

We took Kestrel off, did a system check then clicked to auto and it began to move towards wp1 at 5 m/s at an altitude of 15M. Student was given control of Yaw at the ground station via joystick while I continued to watch Kestrel move down range. It started to approach the treeline, so I changed to stabilize and climbed. Due to the distance and unsure of YAW, I lost orientation. I swicthed to RTL, it didn’t move back, i went back to stabilize and it kept moving down range. There was a wind 5-10 m/s downrange. Finally, getting to small to see and starting to lose video, I put in RTL and prayed :slight_smile:. The telemetry gives me varying amounts in the Wind_Vel parameter, but I don’t know how accurate that is and how it is calculated.

I we have is the .tlog. I am wondering if the winds aloft were too strong for RTL. Looking at the telemetry, it appears the quad was headed towards home, although the GPS track is in the opposite. Did we just get outside the envelope and unable to get back? What is the default behavior in tis situation? It was also moving over sloping terrain, so I’m not sure how it would respond to altitude. It seemed to be climbing when we finally lost signal.

First, I’d appreciate any insight into what may have happened, and, finally, if you were us, were would you be looking for this quad?

Thanks,
Kevin

2

All sounds a little heavy had it flown properly before?

3

I feel for you, having experienced something similar when on an auto mission and ploughed into a forest on the side of a mountain a mile away. Fortunately I had tucked in a gps tracker that I bought from this guy youtube.com/watch?v=_RzZcQBpu4g and even though the quad was on track and had fpv video and telemetry it greatly helped to find it in the dark crawling up a 45 degree trifid infested slope with an LED for light. The battery had disconnected on impact, but the tracker was still active.

I replayed the log and am as baffled as you - a reasonable quad should be capable of over 20m/s so I don’t think a 10m/s wind should have been a problem - was it configured to RTL on loss of signal, or land on failsafe? It ought to have come home or land by itself if failsafe triggers.
Sometimes I found it takes a couple of flicks of the switch to get RTL to register, or so it seemed.

Perhaps get the kids to work on it and come up with ideas, then plan a search party as a project to learn how to cover an area most efficiently?
Too bad your telemetry ran out, otherwise we could have constructed a replay mission to help search for it, but you could make another mission to scan the area - long shot though, as I’m finding out myself!

Hope the quad or gopro footage contains some identifying info to help its return if found.

4

Andy-
Thanks for taking a look.

Yes, we will definitely be installing trackers in the future. We had flown the quad several times before (I’ve been doing rc 30+ years) so I can confidently say it flew well, even ran some search grid type missions.

I’m wondering if at the distance the video or telemetry just overpowered the GPS and it couldn’t figure out where it was. The strange part is it looks like it was pointing home. Hopefully it is on the ridge on the other side of the lake. If it cleared the ridge, it could be several miles down range and we may never find it. It is hunting season, so I’m hoping someone will come across it.

Any more thoughts as to what might have happened?

Kevin

5

I only started a couple of months ago and am still abseiling the learning curve, so can’t yet really work out from the logs what it was thinking, but I would run a few missions to scan the area just in case.
A downed drone is a lot easier to find than the lipo I lost overboard last week and currently trying to find!
(see my other post!)

At 2oz, my gps tracker may be a bit overkill for a phantom or such.
There are lighter alternatives and audible alarms, but you need to be in range to detect while their batteries last.
dronethusiast.com/how-to-track-your-drone/

Cheap gps receivers can be modified with a SAW filter to greatly reject non-gps RFI.
A search on youtube for “gps saw filter” comes up with some interesting things - you can add a tiny SAW filter to the gps antenna, but the nanosoldering skills required are extreme!
I use a Neo7N which comes with the filter built in, and I typically get a lock under half a minute, even with telemetry and vtx running.

Also check out space weather before doing anything that relies on accurate gps:
swpc.noaa.gov/rt_plots/kp_3d.html
(green is good).

If you have an email address/phone number on the drone, then I think there’s a good chance you’ll get it back one day. I suggest taking the dog for long walks in the general area, just in case!

Good luck!

6

Did a little more digging and I think I understand what may have happened. The NAV_SPD was set to 5/ms, which I realize is ground speed, so it should still penetrate a wind. however, the BANK_ANG is set to 2200 for the quanum. I theorize that in the wind it could not achieve enough speed with the 22 degree bank angle. On our second quad I changed the bank angle to 35, and now it can really move. I suspect the wind was just too much for it to overcome based on the parameters set in ardupilot… Learning can be tough :frowning:

Kevin

7

Ahhh!
That would explain it - mine was set to 45 degrees by default when I got it and it’ll do over 50mph.
Hadn’t occurred to me to change it.
Keep us posted if and when it turns up!

8

Hi,

I had a similar problem. I let the quad rise to about 50 m height, were it was caught by wind and slowly drifted away. I flew in loiter mode against the wind, high and low throttle, and upon losing it due to the woods, switched to RTL. It continued to fight the wind, but at a very shallow angle. After a while hunting it through the woods, I found it still hovering and killed it to crash. And crash it did - so at least I have the parts and the video. From the video the problem is obvious: it tilts to about 20 deg but not more into the wind. And that’s just to little.
I connected it to APM planner and mission planner, and I can find the parameter for ground speed (was 5 m/s). However, I can’t find the bank angle setting. Only for the “Mount1 and 2” I can find maximal angles, but for the airframe itself not. Where do I find this parameter?

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@Arduwef

…It’s actually called ‘ANGLE_MAX’

by default on apm 2.6 it’s 45 degrees…
you can find it in the full parameter list / full parameter tree… (use the ‘find’ button on the left )

happy flying :smiley: