Servers by jDrones

Dual-motor tailsitters

(Claus) #1249

Hi folks ,

I finally managed to spend some time on the field with the laptopto tune my Caipirinha2.
It seems the I tuned the params in the wrong direktion. The swining I saw on the axes was due to too low
parameter !! Now it feels pretty save when I do the transitions.
Q-stab and to transition to FBWA works fine in both directions.
Now I have probs with the q-hover …when I switch to this mode my transimitter input is delayed for about 2-3 sec . And it is hard to hover at a decent hight.
I shortly tried to q-loiter - but the flyer was acceleraton and drifting away from the wind - although I had a pretty good gps lock.
Perhaps someone has experience with a similar behaviour.
For now here is my actual Parameter file …

Greez ,

Clausvtol_field7lowwindok.param (15.3 KB)

(lorbass) #1250

My caipirinha can move in hover mode max. 10 kmh. After that it starts pumping.
So if the wind is stronger, it can’t hold the position even in Q_Loiter.
Therefore I never use Q_Loiter.
In Q_Hover I turn the wing to get it back with Roll when the wind is stronger.

Here an Idea for a planned improvement in poste 1219:

(Claus) #1251

Ah okay… :slight_smile:
by the way - how did you realize the 180° tilting of the rotors ?

(lorbass) #1252

I use this servos:

They can be programmed with the programmer DPC-11 for 178 ° on the PC.
Or the dealer can deliver it with 178 °.

(Mark Whitehorn) #1253

Interesting non-vectored VTOL design:

(letpi) #1254

So clever !! I don’t know if this is a vision of future but I like it

(Marek) #1255

New tailsitter design:


canard style with dual motor, but coaxial with counter-prop

2 x BE4114-400kV with 16x5.4 props
2 x ESC 40A
LiPo 6S
Pixhawk with GPS, Current/Voltage sensor, telemetry 433 MHz
Arduplane V.3.8.5
Weight - 2.7 kg

Now - tuning PID’s in QSTABILIZE.
with pitch - ok (P=0.3, I=0.1, D=0.001),
but with roll -> small P values (0.08 - 0.3) not work = great oscillations. Starting to be stable with P=0.8 - 1.2.
Any ideas with this high P values?
Parameters file -> EM-1.param (17.0 KB)

(Mark Whitehorn) #1256

How do you control body-frame yaw? Are the elevons the only control surfaces?

(Marek) #1257

Yes. Only elevons for yaw

(letpi) #1258

With a traditional ardupilot dual motor tailsitter, in all VTOL modes, roll control is given by differential motor thrust. I dont see a rudder too. I guess it means roll control is obtained with vertical canard surfaces ? That would be very new.
your parameters are OK for a first test except q_a_rat_yaw_p=0 and q_a_rat_pit_d=0

(Marek) #1259

Two canards -> one is elevator (pitch), second rudder (roll) plus elevons or flaperons (yaw).
There are also possibility to use difference in RPM of both motors as additional yaw ( similar to coaxial heli).
From first tests - elevons are very eficient in yaw.
For me - the best idea is to use this configuration in „vertical” modes than during transition switch off elevator and rudder and use flaperons as in normal delta plane. But have no idea how to change settings of both canards to fixed position in neutral during transition.

(Peter Hall) #1260

This has now been merged, I removed the second parameter because it turned out not to be useful, should be in todays daily build.

I have been messing about tiring to use real flight for code development, not having a huge amount of luck. First task is to make a real flight copy of the bronco, I have had it flying OK but it seems to do random stuff occasionally. Not sure if real flight is really good enough to evaluate the performance of hovering code.

Anyone got any tips?, what is the best thrust vectored model to to use? So far I started using the CUAV model as it was closest to my bronco and resized the components, its does sort of fly most of the time on the real parameters.


(Marek) #1261

(lorbass) #1262

Large FPV Tailsitter with Skywalker 6.
Successful maiden flight after a long time.

The telemetry reports “Tuning error 0.15”. The compass is not calibrated correct enoughe.
The Pitch Flight is not slow motion, it is so slow even with 30 degrees pitch.

And the docu:

The Parameters.
Nach Test 27.param (16.2 KB)

(Rolf) #1263

Congratulations :trophy:

Thanks for the report and great “PID tuning”-mount. How heavy is the plane? (25 Ampere at 6s ! )


(Jose Ortiz) #1264

WoW very impressive I wish my tailsitter flew that well. mines crashed 4 times out of the 6 times ive flown it. swapped to bigger motors and now it cant fly well at all.

(lorbass) #1265

Thanks for the flowers.
2550 gr without fin and winglets.
But the current measure is not calibrated yet.

(Walter) #1266

Also congratulations!
I am very curious about the consumption in the plane flight.
With a short time to transition and landing (at Belly we calculate 20-25 sec / 30-50 sec) is a long flight time to expect.

(lorbass) #1267

Danke Walter. e-calc berechnet 10 min in Plane Mode bei 50 kmh.
max. Airspeed 77 kmh.

(Henry Wurzburg) #1268

Skimming thought the thread, it seems that most have moved to vector thrust for dual tailsitters…has anyone successfully gotten a plain non-vectored one to fly acceptably? I have my trusty z-84 test platform I use to test AP code changes on or a spare s-800 wing that I would like to try the taillsitter on, but there seems to be little in the way of success stories with non-vectored…any suggestions?