Today I flew my Cyclops EPO for an incredible 7 hours and 8 minutes, covering 301 km (301 km !!!) in one flight.
After flying my Maja for 126km I decided 200km would be my next challenge. I got the Cyclops with that in mind, it was very very efficient straight out of the box and after my first flight test I realised it was capable of much more.
I did 5 flight testing sessions where I tested different speeds, C of G positions and propellers. The data from my last two sessions suggested 300km was possible with good conditions so that became my goal.
I planned my mission with a couple of waypoint path options that I could switch between using do_jump. After a hand launch I switched to auto for a very gentle climb reaching 50m of altitude over about 2km. I flew a few laps of a 2.5km lap, before switching to a 3km lap and then a 3.5km one which used a do_jump command to fly continuous laps at 60m altitude.
To monitor my progress I’d made battery consumption schedules for 250, 280 and 300 km. My calculations said that I would need to run my batteries down to 10% remaining to reach 300 km. The first half of the flight was very calm and I was ahead of schedule. But the wind picked up in the afternoon and it became apparent that I might finish with less than 10%. I tried to help the situation in the last hour by varying my speed around the lap. I flew at 14 m/s for the head and cross wind sections, and dropped to 13 m/s when I had a tail wind. I hadn't done any calculations to support that, it just seemed that I could make the most of the tailwind section by dropping my power there a little.
I’d decided in advance to end the flight when the battery dropped to 12 V (3.0 V per cell) and I could see as I passed the 280 km and 290 km milestones that it really was going to be tight. The voltage was hovering either side of 12 V as I approached the 300 km mark so I knew it was time to bring it in, but I also knew that Mission Planner can underestimate the distance compared to the GPS log. I decided to fly to 303 km to be safe. The way the laps worked out it was 305 km when I hit the ground, and just as well because the GPS log came up as 301 km. If I’d come in when Mission Planner told me 303 I would have been member of the 299 club.
The telemetry log file is 47 MB (linked below) and Mission Planner crashed when I tried to create the KML file (I tried on three different machines). It did manage the GPX file thankfully.
Key specs:
- Cyclops E with V-tail
- APM 2.5
- Panasonic 18650B Li Ion batteries. 4S7P, 23,800 mAh
- Aeronaut 11x9 prop
- Hobbyking telemetry
- Distance covered: 301km (according to GPS log file, 305 km according to Mission Planner)
- Flight duration: 7 hr 8 min 10 sec
- Average groundspeed 41.7 km/hr
Comments
congrats @moglos
what is the motor you are using on that setup? thanks in advance
Very impressive endurance flight..
Like Ted above said, how did you stop yourself going nuts for 7 hrs 8 mins?
Did you go away for breaks? trusting the autopilot, and come back later?
Steve
Well I am out looking for a radio collar on a cat in a minute, long loiter times over game reserves would be very handy. My next platform will record the collars and air quality as well as sending back video FPV style so lots of electric bits to stuff in an airframe. Flying for a long time tricky, keeping sensors going as well is also hard There is already a French company with permission to fly powerlines out to 100km from start.
4m wings and six hours endurance will become a standard!
Hi Trung, yes I remember working towards the 100km not very long ago. I also remember looking at your flying wing as a possible plane for a 200km attempt. I took your stats and recalculated the distances if you filled it with Li Ions, and it would have done it. But then I found the cyclops, I expected it would get me to 200 but after my first day of testing I realised it would get to 250, then each day of testing I found further improvements.
Those spikes were just inaccuracies. If it was real then you'd see half a lap of gliding with no power back down to 60m. It is odd though that the spikes seem to be regular, like they happen in the same place each lap. The APM controls altitude according to the barometer. I got 6m of barometer creep over the whole flight. The reading on the ground after landing was 6m.
I'd love to put the UAV to some good use, or even better earn, some money with it. If anyone can think of applications that need such a long flight time/distance then please let me know. Justin Martin wrote about a mapping application. Perhaps surveying powerlines (or highways, pipelines, rivers, coastlines) could benefit from such a long range
Hi Reto
I didn't actually measure the TOW but I think it is 2.45 kg. And the power consumption was 41.5 for the first half of the flight (the part done at 13m/s). That gives me 16.9 W/kg. The wingspan is 2.6m. There is some room for improvement! I'll have to read through that study you posted (or is there anything you can think of?)
@moglos, Awesome achievement! I joked with you earlier when you were having issues - hinting that you must be shooting for 200km. (ha, was I wrong!) I'm glad you worked out the kinks. I can't say enough how impressed I am. Weren't we talking about reaching 100km only a few months ago? I would love to see this capability put to good use. I wish there were opportunities locally.
It's amazing how much weather can change when you are talking about multi-hour flights. That wind went from dead calm to ~20+kph. I know GPS alt can be notoriously inaccurate, but were those periodic altitude excursions real? Do you know the reason? Thermals? There is a period around 100km where you climbed 40-60m with each up wind leg.
Again congrats, and I look forward to your next challenge.
I was curious about the efficiency of your setup and took these assumptions:
Battery weight: 1.4kg TOW: 3kg Power consumption in cruise: 45W
This leads to the performance index:
15W/kg at 13m/s for a 3m airframe.
This is very good. The maximum theoretically possible performance for your class airframe is around 12W/kg. You are already quite close.
In our faster flying (20m/s) and smaller (1.4m) custom made high performance flying wing we get around 20W/kg. I guess in this class the theoretical maximum would be around 16W/kg
Yeah they are big files. I've had trouble exporting to a csv file too. I think it came to 299mb, Excel couldn't open it, it just gave me the first 3/4.
I also did a timelapse using a Raspberry Pi. It took about 11,000 photos totaling over 12 GB. I'll see how I can get that made into a 3 or 5 min video.
@ moglos - I tried to be nice and parse your tlog file in matlab thinking I could handle the data. Boy was I wrong! It took my computer about 15 minutes to recover. I might let it crunch through it once I go to sleep tonight.
Great work, really impressive stuff. Maybe people like you getting durations like this will prompt some of us to write parsers that can deal with this amount of data!
Thanks for spotting that vova, that was a typo. You're right 7 x 4 = 28.
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