I was on a survey job for the Sacramento Kings new arena and I discovered a few good tips.
• Set your RTL at %30 of battery drain.
• Carry good electrical tape
• Buy a backup Iris+
• Get a lens guard for your GoPro.
I decided to allow my unit drain to 20% and RTL. I was 60m up and only around 100m away. The Droid lady said "Low battery, returning to launch" Sounds good to me. As it's decending I notice I'm well off the mark and headed into oncoming traffic. It's a tight quarters job and you gotta be ready. I begin to nudge it over the K rail and I hear the motors begin to decelerate. I hit hard left and, well watch the quick video.
The gimbal plate cracked in half but I was able to use electrical tape to finish the job. I had a Mobius on there for shits and giggles and the GoPro was the survey unit. You'll see it fly. Gotta hand it to GoPro. That's one tough unit. I did have a CPL filter on there, but if you can use a cheap 3D printed hood, do it. That filter saved my lens.
So if you're ever unsure out there. Trust your gut and RTL.
Replies
As a relative novice, particularly to pixhawk/3dr, I do find this helpful. Extremely helpful. Crispin is the first person I've come across to suggest that flying with battery failsafe active is "stupid stupid." Assuming he is correct, I'd like to know what his rationale is. There is definitely a difference between stupidity and inexperience.
Having said that, I must admit that the more I've flown, I've actually found it to safer without the failsafes on. Instead I concentrate very closely on the ground station app and the Iris+ itself (as Crispin seems to suggest). I fly in pretty remote areas without people around, so I can afford to experiment a little.
My issue with the failsafes (both battery and GPS) is that they can take control of the Iris at inopportune moments. For example, in general I like to land with 50% or more battery remaining, but on a few occasions I've had to push it below 30% because I got myself into situations where I had to go for a back up landing site. One time there were much higher winds than expected and so the Iris had to work so hard to execute the mission - it was an effort to abort and get it to a safe landing zone. I think I ran that battery down to 25% that time. Another time I had a ski break and I couldn't get there in time. And another time a moose showed up unexpectedly and I just didn't want to land anywhere near him so I had to go for a back up.
Anyway, I'm definitely NOT suggesting that anyone else disables the failsafes. I'm just not experienced enough to really make that call. I would be super interested to hear what other people recommend and WHY.
Erik -
My point is that relying on something like battery fail-safe and using that as a "I don't have to worry about the battery" is not wise. Having it as a last resort - I'll buy that.
Jimmy's quote "I decided to allow my unit drain to 20% and RTL." is stating just that. Does RTL not first climb 10 or 20 meters? Not sure on the battery fail-safe. If it is the same as normal RTL then that is hammering an already low battery.
You should have either some form of telemetry reporting your battery voltage or a timer telling you when you have flown x minutes and then land. Eeking out every last drop out of a battery is pointless unless you don't care about the battery.
Sorry to sound offended but I pride myself on safety. I was regretting not returning at 30% I have to fly that spot 24+ more times this year. I'll split the job site in half and be fine at 50 to 60% Another company is stitching the photos so I was hoping to give concurrent data in one pass with the overlap they requested. I am running a SX260 next week so GPS data will be included. (which is also scaring the crap out of me)
It was a test. It failed I get it. I metered the battery after and it said 22%
With all that being said what would you recommend for maximum MAh for a 5100?
Jimmy,
Sorry to hear about your crash. I don't know what kind of accuracy your looking for, but the SX260 GPS accuracy is horrible. If possible, lay out ground targets that you can tie back to your photos. I've actually stop using the SX260 on multi-rotors, because of the weight. I'm using a Canon S100 and SD780 (converted to NIR) for most of my mapping tasks.
I'm mostly flying fixed winged missions (FX-61), but all my short missions on a Y6, soon to be converted to an X8
Good Luck with you future projects
Chad
I still have my S100 but it's stuck on the "Lens Error" thing and I didn't want to crack it open. Should I keep it and try to fix? Can the SX260 plug into the Iris?
what does that plug into on the Iris? I'm not too hip on tapping into the telemetry unit.
It plugs into the Pixhawk flight controller - http://plane.ardupilot.com/wiki/common-optional-hardware/common-cam... .The Pixhawk doesn't have the voltage to trigger CHDK, so you have to use something like this http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLA600 . I like this Eflite controller, because you can use one LED lead for the camera and the other for a LED light. On my plane I put the LED light on the bottom of my plane so I can tell if Pixhawk/ APM is triggering the camera. There are a ton of videos and tutorials on the web, if you cant find anything let me know and I'll put something together.
Here is some examples of the imagery captured with the s100 (09/26/2014) and sd780 (12/14/2014). Use the top right pull out to switch between flight dates - http://dv-proj.com/uavimagery/)
*I dont have an IRIS, but from what I've read it uses a Pixhawk and the camera integration should work.
Chad/Jimmy,
In relation to using the EFLA600 to trigger a Canon S110 (running CHDK) via the Pixhawk, I think I’ve combed thru most of what is floating around on the main forums. Still no dice. My complex;
I’m flying an IRIS+ (Originally an IRIS with the 3DR upgrade kit.) with Mission Planner 1.3.25. The Pixhawk’s back rail is powered at ‘AUX OUT 6’ via a Hobbywing 3A 5V UBEC & Mission Planner parameters are set at;
BRD_PWM_COUNT = 4
CAM_DURATION = 10
CAM_SERVO_OFF = 1100
CAM_SERVO_ON = 1900
CAM_TRIGG_DIST = 0
CAM_TRIGG_TYPE = 1
RC13_FUNCTION = 10
CH7_OPT = 0
RELAY_PIN = 54
RC13 is AUX OUT 5 is RELAY_PIN = 54
When checking voltages at the Pixhawk, the back rail (+ pin) shows a constant 5.26V. The ‘S’ pin at ‘AUX OUT 5’ show’s 3.28V when ‘Trigger Camera NOW’ is clicked in the Flight Data window, or when CAM_TRIGG_DIST is set to something other than 0 & shifts in GPS allow a trigger. All appears to be working!?
When plugging in the EFLA600, I check voltage on an LED lead, & see a constant 5.26V. Shouldn’t this show +/-0V until the EFLA600 see’s the 3.3V from the ‘S’ pin & let’s the 5.26V from the ‘+’ pin thru?
Am I missing something in my parameters? If you or anyone else has run across this, any notes of wisdom would be appreciated.
Thanks,
Chris
I got this... Then just solder a mini USB. But where to power the unit?
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