Hi there!
I tried ArduPlane’s scripted aerobatics with Plane 4.4.2. Tricks I tried were the Knife edge(ID=13) and the Scale Figure Eeight (ID=14). I conducted these tricks as parts of a mission. Two consecutive mission flights were done following the procedure below.
Arming then takeoff with FBWA mode.
In the air switch to Auto mode and play the tricks.
Switch back to the FBWA mode and make landing.
On the ground, disarm then arm again and takeoff.
Change to the Auto mode and play the tricks again.
After the tricks change to the FBWA mode and land.
Disarm
These tricks were played successfully but there were several strange phenomena as shown by the log data below.
Strange phenomena
A) The log data was not separated even if I took the disarming and arming procedure in the procedure 4).
B) As you can see in the message, the disarming timing was 00:05:13.8 and the arming timing was 00:05:13.6. The arming timing is 0.2 seconds before the disarming timing.
C) I used same mission for these two consective flight but the flight paths are significantly different each other and the current and air speed are also quite different,
I can not understand why these strange phenomena happened. Could anyone please teach me.
A) To create a new log file during disarm, LOG_FILE_DSRMROT must be enabled.
B) Disarm time was 5:13.8 and Arming time was 5:18.6.
C) The two flight paths will not be exactly the same, as the wind and other conditions will be different. I don’t think they are significantly different.
The current needed to be increased to get the same power because the battery voltage was lower on the second flight than on the first flight.
Thank you hatnac-san for your quick and kind teaching.
I almost understand your teaching but there remains one phenomenon I can’t understand.
Namely, why the airspeed of the second flight is much higher than that of the first flight? Second flight’s cruising airspeed between the tricks is around 28m/sec and that of the first flight is around 14m/sec.
As my plane has no airspeed sensor I managed its airspeed by setting the parameter TRIM_ARSPD_CM=2400. It is strange for me why the first flight’s airspeed is so slow.
Dear hatnac,
I know that, in usual flight, it is necessary to enable TECS_SYNAIRSPEED for enabling TRIM_ARSPD_CM be effective. But in the automatic aerobatics flight I believe it is not because the manual says as
TRIM_ARSPD_CM: while the script does NOT use the airspeed sensor, it uses GPS velocity to track the trajectory and this parameter to set target ground speeds. As such you may wish to set this (even if there is no airspeed sensor) to a “fast” cruise speed within the vehicles capability. Flying on the fast end of cruise helps deal with wind impacts.
It is written in the “AEROM parameters” section. There is no comments on TECS_SYNAIRSPEED.
Writing this reply I find my mistake that I have been understanding TRIM_ARSPD_CM sets airspeed rather than ground speed. The reason why the airspeeds between the first and the second flights, now I guess it was because of wind effect. How do you think hatnac?
What you are describing is limited to when the aerobatic script is running. It appears that the ground speed is controlled near 24 m/s during the section where the mission item “NAV_SCRIPT_TIME” is running. For all other segments, the flight is in Auto mode and the airspeed is not controlled to TRIM_ARSPD_CM unless TECS_SYNAIRSPEED is enabled.
