Is there a way to use reverse thrust after touchdown just as comercial jets do?
I don’t need a steep approach but I need a short rollout.
Any comment would be appreciated.
https://ardupilot.org/plane/docs/reverse-thrust-setup.html
Are you trying to do what is described in the link above?
No. My landing approach is fine without reverse. I would like to use reverse as brake during rollout.
Did you read the link? Because it is explaining exactly how to set up arduplane use reverse thrust. In the air or after you have touched down and want to stop the planes momentum.
Yes I’ve read the link several times; this is what it says about reverse trhust in AUTO modes:
Automatic control by ArduPilot in auto-throttle modes (AUTO,CRUISE,FBWB,etc.) for increased descents without airspeed increases, especially during automatic landings to control flare and pre-flare airspeeds more accurately with steeper glide-slopes.
Maybe it does reverse thrust after touchdown as well, but that is not mentioned in the link and I’ve never seen a video of it happening in a full autoland. I just wanted to avoid the hassle of changing the ESC if its not going to do what I need.
Moreover, if it reverses during rollout… How much reverse power is applied? What is the target rollout speed? What is the condition to stop reversing? Maybe reaching a low groundspeed like 1m/s or complete stop 0m/s?..
This is directly from the link
Next, how it will be controlled must be decided. The options are:
- Pilot control with the throttle stick. Above the zero thrust (idle) stick position will control forward thrust, while below will be reverse thrust. Within the deadzone (RC3_DZ), is the zero thrust position. This allows pilot control on approaches or descents in non-auto-throttle modes (MANUAL, FBWA, etc.)
- Automatic control by ArduPilot in auto-throttle modes (AUTO,CRUISE,FBWB,etc.) for increased descents without airspeed increases, especially during automatic landings to control flare and pre-flare airspeeds more accurately with steeper glide-slopes.
- Both of the above.
In order for it to work the only thing you need is a bi directional esc. What brand of transmitter do you use? Are you only trying to use the reverse thrust in auto flight modes? I would set it up to have full throttle like normal and then use a switch to turn the throttle into the reverse thrust throttle. So that way when you land flip the switch and jam the throttle until plane has stopped
Of course it will work in MANUAL mode, I don’t even need an autopilot for that. What I want is full autolandings without pilot intervention and with reverse thrust after touchdown.
how do you de reverse ? I can’t manage to stop the motor spinning in reverse after disarm. can you post any parameter or the setup of servo and rc values from ardu? I am having the issue of disarm making the motor spin in full reverse. thanks 
You might have to look into Lua Scripting for this. Should be a fairly simple script to turn motor to reverse after landing until ground speed is < 2 m/s (or whatever number you want.)
This might be because you have 0% throttle set to mid-stick. You probably need to set neutral trim for RC3 to 1500.
Daniel, you should have included that information in your last post, in your first post when you posted it. You said nothing about auto landing. The fun of flying to me is actually flying my planes not having the autopilot fly it for me. Because of that I assumed you where talkin about anytime your planes lands, no matter what you need it to stop. So I pointed you in the right direction to set your plane up to do that.
In the wiki page it states,
Automatic control by ArduPilot in auto-throttle modes (AUTO,CRUISE,FBWB,etc.) for increased descents without airspeed increases, especially during automatic landings.
Sometime the only to see if it works is to try.
Good luck on getting this working. I hope it is what you want. If you find out it doesn’t reverse after landing on there github page is where you request features. The developers are over there.
You are completely right there. I should have written auto-landing instead of just after touchdown. For me the hobby right now is the other way round; I have flown RC planes manually for many years and what I find interesting is to make them fly and land autonomously as well (or better) than a human pilot.
Sorry for the misunderstanding. Actually I’ve found a way to test if that will work before changing the ESC. I have set a free servo output as AIRBRAKES; even if I don’t have airbrakes or a real servo connected to it the output will be recorded in the SD LOG. According to the documentation AIRBRAKES deploy at the same times that REVERSE is activated so looking for the AIRBRAKE graph I can deduct what reverse would do… I’ll test that in my following flying session and will update this thread in case others are interested. Thank you for your contribution and happy flying!!
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It sounds as if you are headed in the correct direction. I’m interested to know the results of how the air breaks work on your next flight.
I finally bought a BLHeli ESC with reverse feature and configured reverse throttle as per arduplane documentation.
I can confirm that it works great to increase the approach angle when AUTO-Landing; However, now I can also confirm that arduplane (4.0.8) does NOT apply reverse throttle to slow down the plane after touchdown. The motor is stopped when flare begins and is never activated again.
Therefore, my feature request would be: Add full reverse throttle as defined in THR_MIN (negative value) right after touchdown is detected and stop the motor when gps groundspeed is below a threshold value (around 1m/s could be fine).