Reverse Throttle

PX4 Autopilot
1

I’m designing a boat and would like the capability to reverse its throttle, and also make sure that when it arms, it’s not going in full reverse throttle, but rather arming when the RC stick is centered.

I’ve read some posts on the forums claiming that reverse throttle is achievable by keeping the stick center when calibrating RC. However, I cannot finish calibration when trying to do this.

Is this a problem with my RC setup? Or on QGC’s end?

2

The only way I was able to get reversing thrust on px4 was some custom software. Ardupilot makes it pretty easy though.

3

How did you do it with Ardupilot?

4

I believe there is a “use rev thrust” option. It can be controlled via a switch or used in the loop on landing approach.

1 Like
5

The reversed thrust can be set up in QGC. It is not mentioned in the documentation, but you have to keep the left stick (throttle) centered during calibration Support normal car ESC with reverse · Issue #11992 · PX4/PX4-Autopilot · GitHub.

Edit: Sorry, you have mentioned that you have tried centering the stick. However, this method worked for me. Try this:

QGC will ask you in the initial steps of the calibration to push the left stick down, up and down again. Perform these steps. after that, QGC will ask you to push the left stick down right, then down left and so on. Here, you have to push the stick to the right, left, and so on instead of down right, down left, etc. When QGC continues with the right stick, perform the calibration steps while centering the left stick. This will enable reverse thrust.

6

Hi!

Strangely, this method did not work for me. Calibration did proceed, but reverse thrust is still not enabled. What led you to learning of this method of enabling “reverse thrust”?

I’m concerned that it may be due to my radio controller not being fully compatible with PX4

7

The link in my last post lead me to this method. I am using the Herelink and there is an optional check box: “Throttle Center 0” which shifts the throttle value of the throttle gimbal (a centered gimbal translates to the lowest possible RC throttle value). You might have similar options on your RC.

8

Ahh that makese sense then. I’m using the AT10II Radiolink RC, which is primarily used for flying vehicles.