Autorotation thoughts

Hi,

I've been flying my heli for a while but I came across a problem, which doesn't happen quite often but it may be important for safety. It's the power failure and autorotation.

Recently I had a major failure of my battery during the flight, the battery just suddenly died that my motor has stopped but the servos were still working thanks to the separate battery for servo and PX4. Luckily I was about to land my heli about 4m high so I heard that the motor had stopped.

I changed to stab mode, and tried to do my first autorotation in my life without any experience and I'm glad I was not panic. Although my autorotation was not well performed, the stab mode helped a lot. In the end I just had a slight hard landing, nothing was broken.

After this accident I was thinking, whether it's necessary to have some way (from our PX4/Pixhawk) to perform the autorotation or maybe a warning to the pilot when such failure happens. If I wasn't close enough to my heli I'll have no idea that the motor had failed and the heli will sure lose all its power before I realized what was going on.

If it's a large heli like 600 or 700, it will sure turn out to be a disaster. Afterall for a UAV a lot of things are controlled by the FC, we may not notice it until it's too late, and unlike the 3D pilots, our heli can be far away and we won't feel anything. So yeah, I kind of feel that we may need some safe mechanism through Ardupilot, to protect the heli, and maybe protect other people.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • I almost forgot, somebody has already done auto-autorotation with Arducopter:

    Unfortunately they are not yet sharing back to the project.  They are not required to unless they were to distribute the program.  I believe they were just using Arducopter as a basis to develop this feature for their thesis.

  • Hi David, yea I feel quite lucky it just happened in such low altitude. It will probably crash hard if it happened higher.

    What's the common pitch range people using for Stab? I have a range from about -8 to +10 at the moment and it seems working pretty well though. The only thing is that the "throttle mid" is about 65%, the pitch is around +5 degree I guess, so there would be a little jump when I switch to Alt-Hold. A bit annoying with this jump and I need to raise throttle (pitch) stick before switching back to Stab, but since landing with Alt-hold works very well for me, I don't use Stab as often as before.

    BTW, I don't know much about autorotation, how much negative pitch is needed for a normal RC heli, for example a 450 and 500 class?

    • This would be awesome if you could get it working! I came across this project at Stanford a few years ago... it's pretty relevant!

      https://www.youtube.com/watch?v=3wI4dwqfIdc

      http://heli.stanford.edu/papers/AbbeelCoatesHunterNg_aaoarch_iser20...

      • Rob, I practice on my simulator a lot.  Its fun. There is a target you try and land on. Of course if you screw up you just try again.  I don't know if 3 or 4 degrees will be enough.  By the time you realize you have a problem your headspeed has probably slowed a lot and is 4 degrees going to get it crank up enough to flare out for landing.  I have never done one in real life.  It would be to expensive to practice.  I also have about 4 degrees negative in STAB.  Next time I am practicing on the simulator I will pay more attention.

        Wait a minute.  I am installing a C.C. Phoenix Edge on my 550 this evening.  It has a autorotation bail out feature that can be programmed with the castle link. Anyway, sooner or later everyone who flies a heli's will need to attempt an auto.

        Regards,

        David R. Boulanger

        • I am looking to buy a simulator, but keep on getting caught up on the question of "which one".  Obviously Real Flight seems to be the most common, but I've also heard it's not that good, from a technical standpoint.

This reply was deleted.

Activity

DIY Robocars via Twitter
RT @DanielChiaJH: Great racing against @a1k0n today at @diyrobocars! Pretty cool to both break sun-9s at the track today I think I got very…
3 hours ago
DIY Robocars via Twitter
Broadcasting the @circuitlaunch race live now at https://m.twitch.tv/diyrobocars Races begin around 2:00pm PT
8 hours ago
DIY Robocars via Twitter
RT @a1k0n: ran a huge number of hyperparameter tuning experiments yesterday; now I can train a new policy, far with better quality, in 15 m…
9 hours ago
DIY Robocars via Twitter
RT @a1k0n: Did I get rid of hand-tuned parameters? Yes. Am I still hand-tuning more parameters? Also yes. I have a few knobs to address the…
Monday
DIY Robocars via Twitter
RT @a1k0n: I'm not going to spoil it, but (after charging the battery) this works way better than it has any right to. The car is now faste…
Monday
DIY Robocars via Twitter
RT @a1k0n: Decided to just see what happens if I run the sim-trained neural net on the car, with some safety rails around max throttle slew…
Monday
DIY Robocars via Twitter
Sep 24
DIY Robocars via Twitter
RT @SmallpixelCar: @a1k0n @diyrobocars I learned from this. This is my speed profile. Looks like I am too conservative on the right side of…
Sep 24
DIY Robocars via Twitter
RT @a1k0n: @SmallpixelCar @diyrobocars Dot color is speed; brighter is faster. Yeah, it has less room to explore in the tighter part, and t…
Sep 24
DIY Robocars via Twitter
RT @a1k0n: I'm gonna try to do proper offline reinforcement learning for @diyrobocars and throw away all my manual parameter tuning for the…
Sep 23
DIY Robocars via Twitter
RT @circuitlaunch: DIY Robocars & Brazilian BBQ - Sat 10/1. Our track combines hairpin curves with an intersection for max danger. Take tha…
Sep 22
DIY Robocars via Twitter
RT @SmallpixelCar: Had an great test today on @RAMS_RC_Club track. However the car starts to drift at 40mph. Some experts recommended to ch…
Sep 11
DIY Robocars via Twitter
RT @gclue_akira: 世界最速 チームtamiyaのaiカー https://t.co/1Qq2zOeftG
Sep 10
DIY Robocars via Twitter
RT @DanielChiaJH: Always a good time working on my @diyrobocars car at @circuitlaunch. Still got some work to do if I’m to beat @a1k0n howe…
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: My new speed profile for @RAMS_RC_Club track https://t.co/RtLb7TcgIJ
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: Practiced at @RAMS_RC_Club today with my new @ARRMARC car https://t.co/AEu2hCx89T
Aug 28
More…