MRC87 what kind of down falls were you seeing with AVA?bGenerally speaking I was satisfied with AVA, but hated the reduced functionally of their version of mission planner. And we couldn’t get their camera trigger to work consistently.
I’d like to see some confirmation that you have the right motor order for frame type 11. If you run motor testing from the GCS in sequential order, can you tell us what order the motors spin in? I assume you are familiar with the motor tester? What GCS are you using?
After that I’d suggest you do ground testing in MANUAL mode. Do the front 4 motors power up, and follow throttle commands?
I guess I shouldn’t say AVA and should more say the reduced functionality that came with AVA in Mission Planner like you guys have noticed, mainly terrain following and the grid survey system that MP has. AVA was simple actually just didn’t have enough features in their truncated version of MP! The FF6 is a great platform, we have an internal mounted QX1 with a seagull Map2 for camera triggering and it seems to be where it is at, minus not having a hotshoe to trigger a emlid reach for PPK! we also upgraded ours to bigger 6s bats with 3d printed battery boxes. I just like not having 4 motors that are only used for a few minutes of flight, tagging along for the ride!!! Only downside is when you flip on a quadplane quad motors its stabilizes very quickly not like the ff6 where you have to wait for motors to move back to vertical position!! I guess there are ups and down sides to both!!!
Ran this test this afternoon. Here is the order: front right top, front right bottom, tail top, tail bottom, front left top, front left bottom.
In q-stablize, all the motors spin up fine and respond to throttle commands. Same thing in q hover. The apparent anomolies start when I go to FBWA. It tilts to about 45 degrees and then with all six motors running, then 1 or 2 of six motors stop.
I also noticed in the log file above, RCOUT3-8 are not syncronized, they are slighly out of phase, which is why I did the manaul ESC calibration.
Thanks Tridge
I am using the latest version of mission planner that includes frame type 11
David,
Hopefully, you saw this line in my first post.
Tilt Servo = Servo 11 = 41 = AUX3 (Note that this is normally AUX1 on AvA setups)
Also, you then need change the Servo 11 Max/Min settings to align with hover and forward flight modes per the FF6 manual.
Thanks Greg. Tilt is on aux 3 and the servo11 out values have been adjusted to get the appropriate eleveon deflection.
Can you do me a favor and check how your FF6 transitions on the ground with the engines running. Mine works great in q stabilize q hover and fibwa when the engines aren’t running. But when engines are running some of the forward engines stop running. Which ones is random
Thanks,
David
I am prety sure this is correct behavior. It’s rotating to Q_tilt_max and stopping becuase it has no forward airspeed.
now that you’ve checked the motor order, the next test is MANUAL mode. When in MANUAL mode do the motors tilt all the way forward for fixed wing flight, and do all 4 front motors follow the throttle input?
I had a look at your log “2017-10-04 11-39-53.bin” and I don’t see anything unexpected there. I do see times when one of the front motors goes to zero, but that is because its opposite paired motor has saturated. To understand this I’ll need to explain a bit about what it is doing when it is in this “low speed ground test FBWA transition” mode.
During this test the motor tilt is limited to Q_TILT_MAX, which is 45 degrees. It wants to accelerate into fwd flight, so the motors have tilted to that angle. They won’t go beyond that angle till the aircraft has enough airspeed for fixed wing flight.
While in this state the multicopter flight controller is in charge, stabilizing the vehicle in roll, pitch and yaw, while also trying to hold height. At the same time it is compensating for the tilt of the fwd 4 motors.
If the aircraft is rolled slightly to the right then it will put more power on the right motors to try to bring it back to level. If that roll persists then it keeps putting more power on the right motors. Eventually the right motors saturate as they can’t go any faster. At that point in order to try to stabilise the vehicle the only choice it has is to reduce the power on the left motors. It will keep doing this to try to stabilize in roll until the left motors are at zero.
If you have a look a your log you can see this in the RATE log message. The RATE.ROut goes to -1, meaning it is trying as hard as it can to roll the aircraft left. It isn’t actually managing to roll it left as you are holding it in your hand, but it doesn’t know that.
This is all complicated by the scaling factors it has to apply for the motor tilt, that tends to exaggerate the amount of throttle change on the fwd motors, making it more extreme than you would see in QSTABILIZE mode.
Cheers, Tridge
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tridge,
Sorry to raise alarm were none existed… with your comments I will try my first flight tomorrow.
Thanks for taking the time to allay my concerns.
Thanks. I’ll update you tomorrow.
Dave
no problem at all! I was very nervous before my first FF6 flight too.
Did you test in MANUAL mode?
Not yet. I’ll do that before I do my first airborne test…
Yeah my apprehension is due to this airplane isn’t very survivalable. If it crashes, I doubt I’ll be able to salvage much.
Tridge,
Just did a quick test in manual. As soon as I go to manual, the tilt motors rotate full forward and the aft two motors stop and i have excellent throttle response.
What plane mode do you recommend for my first transition.
Thanks for all the help, insight and and great work.
Thank you,
David
I usually have 3 modes setup on my transmitter for a first transition flight of a quadplane:
- QSTABILIZE
- QHOVER
- FBWA
I arm in QSTABILIZE mode, and then do a quick flight in that mode to make sure the tuning is OK. Then I fly in QHOVER mode, and make sure the altitude hold is OK.
Then I transition to FBWA mode for forward flight.
Before you do the flight, can you post your current parameters for a check? Looking at your parameters in the 4th October log I see a few things that don’t look right:
- you have ARMING_CHECK=0, that should be 1
- you have BRD_SAFETYMASK=256. Why is this set?
- you have THR_FAILSAFE=0. What do you want to happen if you lose RC control?
I also strongly recommend that you do a stabilization check in FBWA mode while disarmed, making sure the elevons are moving in the right direction to correct attitude.
Reversed elevons are a distressingly common way that people lose aircraft
I also note that you have the old PTCH2SRV_P value.
You should also use PTCH2SRV_P=1.8
ahh, I also notice now that your battery voltage is 22V, so you are on a 6S setup. That means your flight will probably be the first flight with a 6S FireFly6 with this firmware as I don’t think Greg has flown his 6S airframe yet, and I only have the 3S setup.
The main difference could be some tuning changes needed to the multicopter controller. I actually expect the tuning to be pretty similar, but make sure the plane is nicely tuned to fly in QHOVER before you do your first transition. Your “emergency” mode if the transition goes badly should be QHOVER, so you want to be sure that QHOVER has very good control, and can recovery attitude quickly enough if things go bad.
So spend a couple of minutes flying in QHOVER before you transition, giving significant roll, pitch and yaw inputs, and height changes. If you are not happy with how well it flies in hover then hold off the transition flight and post a log for us to look at.
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Man your attention do detail is awesome.
I had the arming checks set to zero since I was testing indoors, Will change before first flight.
BRD_SAFETYMASK=256 was set to this to test camera trigger while not activating servos to elerons and tilt. Kind of a moot point since the FF6 doesn’t have an safety switch Not a big fan of that so I may add a safety switch
THR_FAILSAFE = 0. Not sure what I am going to do with this. We fly auto mission BLOS over rural terranin and occasionally beyond the range of the transmitter. I think continuing the mission is just as safe as RTL in the event of lost RC.
it already has the ability to continue a mission in AUTO mode without RC. The interesting part is where you are testing in visual range and find you have a dodgy receiver. Much better to set Q_RTL_MODE=1 and THR_FAILSAFE=1 so that it will do something sensible (like come home and land) if it loses RC. Otherwise if you are in FBWA mode and lose RC then it will fly off into the distance forever. Great way to make the news on your local TV station …
Always test that RC failsafe does work before you fly.
Thanks Tridge,
Q_RTL_MODE is already set to 1. I’ll set THR_FAILSAFE= 1 as well.
I’ll ensure everything is good in Q hover and Q stablisze before transistion. Regardless it will be a little nerve racking the first time.
Dave
yep, it always is. One of the things I’ve noticed is that my wings wobble a lot more on first flight than later flights on any new plane. It seems to be correlated with the nervous twitches on my fingers 