/Magnus
Ardupilot Mega test flight report.
Today i did my first test flights with the APM installed in my Multiplex Twinstar II.
I tested the Stabilization mode and the Auto mode with six waypoints in a 1,4 km
long track.
Equipment
* Multiplex Twinstar with brushless motors.
* 35 MHz RC
* APM with shield
* Airspeed sensor
*U-blox GPS
* Aerocomm 868 MHz radio modem (Not used)
AP config
*Running software built 2010-09-07
* Custom config file exceptincreasing cruise speed and cruise throttle.
* Altitude mixing set to50%
* Air speed sensor enabled
Weather
* Wind about 10knots with gusts up to 16 knots. Moderate turbulence.
Result
Stabilizationworked great with standard settings. Maybe it responded to stick
movement a bit to abruptly, but it was really steady in the quite
turbulent air.
Auto mode worked fine. The plane flew the coursewithout any real problems and then started to loiter above the home
position. One strange thing i noticed was that the plane changed
direction during loiter after a few turns. Could it be that at first it
tried to reach home position but never came close enough and then when
it reached home it started circling in the other direction?
Altitudeholding worked fine and it was fascinating to see the AP cut the
throttle to zero when the plane reached some thermals when fighting
against the wind to reach a waypoint. You could really hear the throttle
going up and down during the flight.
The only thing that didn'twork was downloading the log files after flying. I could only read a
few lines before i got an error. I will file this as an issue at Google
Code.
Over all this was a real success. I now feel that i have aplatform that is easy to setup, maintain and fly.
Next time iwill add telemetry so i can log things as well so i can show off nice
maps.
Comments
The Elevator surface is removable. I did some cutting in the EPP so it slides in. To keep it aligned i have mounted a thin aluminum tube in the fuselage and a 6 cm carbon rod in the stabilizer. To keep it in place there is a nylon bolt that goes through the stabilizer and into a nut in the EPP.
The servo has a connector that is glued in the fuselage so it connects itself... :)
/Magnus
Jim
I'll try to add some photos later today. I have had so little time to spend on this so the documentation is suffering. ;)
In short i have done the following:
* Replaced stock motors with brushless. One ESC in each motor pod.
* Mounted the rudder and elevator servos all the way back (mounted on the fin and on the stabilizer)
* Made the horizontal stabilizer removable so the plane would fit in a the box it came in
* Opened up larger holes between the different compartments in the fusaelage. This way i could place the radio modems in the compartment behind the wing.
* Receiver is placed under the wing
* i have two three cell Lipo packs after each other in the bottom.
* I cut out foam in the canopy so its hollow
* I cut out some foam from the main compartment (under the canopy) so i could place the APM above the batteries. The APM is fastened to a piece of balsa fastened to the plane with velcro. this way its easy to remove it if you like. (And when you want to remove the batteries)
* GPS is placed in the canopy. antenna sticking up.
* Pitot tubes are in the nose but placed high so they don't stick out that much.
* Canopy is held in place by magnets and a piece of plywood.
/Magnus
Would you be able to share a few pictures of your TSII install? I built one up as well, but had a few issues and had to shelve it in favour of Old Faithful (EZ*). Would love to learn from your experiences there (and maybe get myself motivated to finish mine).
It did exactly what you are describing. First some ccw turns then waggled a little and then started to circle clockwise. As i remember it the plane banked more during loitering (cw) than when trying to catch the waypoint. I set up max bank angle during navigation to 35 degrees.
/Magnus
It is normal for it to change direction once if it is homing on the location and enters in a counterclockwise fashion. Loiter is set up to always go clockwise, so once it switches from homing to loitering it will reverse direction to go clockwise.
When you say "Stabilization worked great with standard settings.", do you mean the PID values that were developed for the EZ* or have you modified the PID settings for the Twinstar II?
I have a Twinstar II with brushless outrunners that I plan to use to try out the APM/Mega Shield combination.
Regards,
TCIII
I have Aerocom 896 too but my can work on maximum 57600 baudrate. APM telemetry works on 115200 speed, can I change serial baudrates and APM will work with standard AP GCS?
If yes how to do that?
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