Hello everybody,
today i had my first lessons to obtain A2 certificate. We used a Italdrone UAV which has a clever arm system procedure.
At first arm motors wont spin at maximum rate even at full throlle. They start spinning diplendently on which command is given. For instance with full throlle all motors are spinning at low rate, with full yaw only two related motors spin, with full roll only two related motors spin. It’s like a motor test related to which command is given. In this way is possible to test if motors are ok and if yaw, roll and pitch are set in the correct way as in my trasmitter.
After 5 seconds of no command, the system auto disarm. After this procedure, a double imput with a three way lever should be given to let procede with the second arm .
At this point it’s possible to arm the drone and start mission.
Is there any feature already incorporeted in mission planner with pixhawk autopilot?
I suppose that special arming feature looks cool, but in reality if you constructed your multirotor properly and parameters and tuning are good, it should never change and would always work. We should all be observing all motors spinning at MOT_SPIN_ARM stage, then you have to increase throttle or Arducopter will disarm.
You could potentially do something similar with LUA scripting.
Or you could even add another switch function in you transmitter to limit throttle output, until switched.
Thank you all for yuor answer.
I already know the motor test function (and still using it before mission start).
On the other way i think this is a laborious solution because i should have mission planner connected and use its special feature.
For example i built a easy and small quad plane where telemetry is directly shown on transmitter display. In this case i’m not using mission planner, conseguently motor test not available.
Equally MOT_SPIN_ARM is used to let spin the motor at desidered rate after arming. I’m using this feature but i don’t know if motor numeration are still fine.
I know that once our copter is set, it should be work fine everytime, eventhough a check procedure before flight time it’s never a bad idea.
I’m interested in a LUA script, but i’m not familiar with it. May you tell me more about it?
thanksss
Unless you physically change something, or change motor related parameters then you wont need to keep checking with the motor test. If you are worried about parameters being changed by accident then save a param file, strip out the unnecessary bits and reload it periodically.
You would need to strip out the read only parts and dynamic calibrations. Use a text editor to remove these from the param file you saved:
Now save that as your Master go-to param file and you can just reapply it if you have any doubts. If you do make any param changes in the aircraft, also make them in that master file (or wait till after the changes have been tested). You can even save versions of the Master for change-tracking. Adding reverse date format in the name keeps everything in good sorting order in a directory. Something like:
Master-params-MyMAV123-20211030
Keep in mind all the parameters can easily be extracted from every .bin log file. MissionPlanner even does this for you when you download the bin log files. So you can easily go back to params from 4 flights ago when everything worked (for example)
LUA scripting is in the doco, but unless you’ve got time to throw away I dont think it’s worth the effort for some funky startup proceedure. It’s best to put the effort into neat detailed construction and correct tuning.