On 1.9.0 stable, v3, strange controls behavior in manual mode

#1

I’ve built the stable firmware for a v3 target. When I’m in manual mode I’m getting some strange behavior from the throttle. The actuator_controls_0[3] (which I expect to be thrust), gives a value of ~58 when the stick is centered and near 0 at full stick up or down.

I’d expect a value around 1.0 at full stick up. This is what I see in SITL.

Here is the plot of me moving the throttle stick full up and down (note the peak occurs during center stick).

#2

Can you provide a log?

#3

https://review.px4.io/plot_app?log=4a38b5fc-4684-4b16-9313-16dcda6294cd

#4

The pertinent part of that log:

#5

Your hover throttle (MPC_THR_HOVER ) is set to 59, which is out of range. I assume you meant to set it to 0.59?

#6

Doh! That is absolutely correct. I saw that in SITL the value was set to 5900%.

Funny this was protected against in both SITL and 1.8.2. I’ll check if lowering this value fixes the problem.

I think this still looks like a bug. I’ll post it to the issues on GitHub if I can confirm that MPC_THR_HOVER is the culprit.

#7

Did QGC not protect you from setting that value?

#8

It got set in a startup script and my guess is I didn’t reset the parameters.