We are building a tailsitter drone and are having issues with autonomous flight.
Our drone only operates with quad motor setup, without additional control surfaces. We’ve managed to get it flying in Stabilize, Acro, FBWA, and FBWB modes, and it flies quite well in these modes. However, the main issue arises with mission planning.
When we upload and activate a mission, the drone takes off and flies toward the next waypoint in VTOL mode. For some reason, it does not transition to airplane mode. We’ve tried adding separate VTOL_TAKEOFF and Do_Transition_VTOL commands to the mission, but nothing seems to work.
Perhaps someone has suggestions and can help us.
I’m attaching an drive link to the logs from our recent flights and the mission we tried to fly.
I really recommend setting ARMING_CHECK to 1. If it won’t arm with the check set to 1 there’s a problem that’s probably going to cost you in the future.
Thanks for replying so fast.
we have wind pretty much every day at the moment (3-5 m/s).
I’ll put the arm_checks back in.
But could that be the root of all the problems?
We’ve tried this on several days, switching from FBWA to auto mode mid flight, but it still transitions back to VTOL in auto.
I’ll mention that things that might be ordinary for you could be new to me, as this is the first VTOL aircraft we built.
Additionally, I’ll mention that we haven’t been able to perform autotune due to the wind, so we’re currently using manually set parameters(we have a smooth flight in Q_ACRO, Q_STABILISE, FBWA and FBWB). Could this also be contributing to this behavior, that we haven´t done autotune?
I don’t know why it’s not transitioning. I don’t think it’s a result of lack of autotune. The tune on this in quad and fixed wing modes seems reasonable. Room for improvement but I don’t think it’s off enough to be the cause of the problem.
I think this is a configuration issue, but I’m not familiar with this configuration of VTOL to say what the trouble is. I ran your mission in the sim and that transitioned just fine so it’s not the mission per se. And I haven’t run into this with the tilt rotors and 4+1 VTOLs that I’ve worked with. I think this has something to do with the tailsitter/no control surfaces configuration. Hopefully others can chime in.
Hello!
I got this plane to work on an autonomous mission. We started thinking that maybe the pitot tube, which measures the speed, might be giving incorrect readings because when it’s in VTOL mode, the pitot tube points upward and tilts along with the fuselage when transitioning to forward flight. In the moment it flies in VTOL mode, the pitot tube essentially ends up measuring static pressure.
So I set q_assist_speed=0, which disables it during the transition. Additionally, I discovered that when creating a mission, you need to input a number in the field for the transition from VTOL to fixed-wing flight, but I didn’t notice that before.