I have an MRobotics MS5525 Airspeed Sensor on my quadplane and in the last few flights I have had problems in getting the plane to disarm. I think the problem is the Airspeed sensor not showing an accurate reading. The picture below shows the Airspeed from the sensor never returning to zero even if the plane is on the ground. To be completely honest I am now not even sure if the sensor is setup correctly. Enclosed is complete log of this flight.
For what it’s worth, I also had issues with this sensor drifting. To me it looks like you could be losing a connections or having a wiring issue. I haven’t had cases as severe as you.
I’ve definitely seen bad airspeed from the static port not being “static pressure” so make sure yours is not seeing extra airflow.
If I recall, I’ve also seen suspected electromechanical noise corrupting airspeed sensors. Is it easy to post some photos of your setup showing where the pitot tube, the airspeed sensor, and other components are physically located in your craft? (If not, don’t worry about it… check the wiring and connections as @Naterater suggested)
Below is a link to the requested picture
The strange thing is this only started to happen in the last 2 flights?
Thanks
Nothing looks suspicious to me. Have you checked your pitot and hoses for any dust/dirt or blockage? That might cause the symptoms you’re seeing.
Also, it’s hard to tell what wires are what… but if the thick red wire running from the nose under the PixHawk is the main battery-to-ESC, and its easy to move, I’d move that away from other electronics and wires to avoid possible electromagnetic noise issues. (Maybe it could be run down the plane’s right side? Hard for me to tell from a photo)
Hi David,
according to the logfile the pitot tube is located in the propwash.
See the red circles in the diagram: as soon as you decreased throttle, the airspeed goes down, although the gps speed does not change. That happens in FBWA mode two times. When hovering the propwash seems to have also influenced the pitot tube. In any case, the installation location is in my opinion unsuitable for measuring the airspeed. The calibration will therefore also be incorrect.
Do you have a picture of your complete plane? it seems like a really interesting quadplane with 2 tiltable frontmotors ?
Regards Rolf
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Rolf
Thanks for looking at my logs.I will get the pitot moved a bit further forward. As a said earlier strange i didnt see this before.
Below is a links to a few video’s and some random pictures
David
A really great plane - congratulation.
Rolf
Rolf
Repositioned the sensor as discussed to almost the front of the plane well away from prop wash and still cant get consistent reading… Each time the calabration readings are different. sometimes + others negative. a value of about 47 appears to give a better and more consistent result.
David Ardis