Convergence with airspeed sensor [solved]

[Sejin_J]

Hello,
I’m conducting a flight test using a convergence.
As I know, convergence firmware doesn’t require an airspeed sensor.
Here are some questions.

1. Is it estimate the speed using a GPS sensor? or not need for transition control?

2. If I want add a airspeed sensor, how to try that?
   (Parameter “FW_ARSP_MODE” already 0,
   and FCC doesn’t recognize airspeed sensor connected.)

Thank you

[sfuhrer]

Hi @Sejin_J,
It’s always better to fly any VTOL with an airspeed sensor then without, as it increases the flight performance and safety (e.g. tighter attitude setpoint tracking).

About your questions:

1. Currently the airspeed sensor is the only way to get an airspeed estimate. We are working on enabling estimating it (at least roughly) with groundspeed minus windspeed (see https://github.com/PX4/Firmware/pull/12353). Currently, the controller switches to a mode where airspeed is not required, and e.g. assumes that it is constant all the time.
2. FW_ARSP_MODE needs to be 0, that’s correct. Have you by chance set CBRK_AIRSPD_CHK to something not 0? Otherwise I would need more information about your setup to find out why it’s not working in your case. (autopilot, airspeed sensor, firmware version,…)

[Sejin_J]

Thank you!

I solved this problem by modifying the parameter (CBRK_AIRSPD_CHK)