Throttle is not working in altitude

🧪 Flight Testing & Log Analysis
1

I’m installing a PIXHAWK4 MIN with Firmware version 1.9Beta.
I was using the firmware 1.9 because implemented hardware is not fully compatible with the 1.8 firmware (mainly regarding the GPS antenna).

Sorry, I’m going crazy with a really strange behaviour with the throttle.

It seems that the system in Altitude the PIXHAWK4 ignore the throttle when the stick position is less than a threshold (more or less 75%). You can directly check it in Flight review:
https://logs.px4.io/plot_app?log=d29ca377-61e3-42f2-8628-a265cc935f32
Compare the graph “manual control inputs” (throttle line) with “Actuator controls”.

image002.png799Ă—693 53 KB

I’m not evidencing this behaviour in the Stabilized mode. The throttle is working fine but I have a strange YAW problem. It seems the system continuously increases the yaw! You can directly check it in Flight review:
https://logs.px4.io/plot_app?log=1f9e1f64-daf9-4dd4-adc9-4cb4807140f0

image003.png788Ă—692 60.1 KB

Compare the graph “manual control inputs” (yaw line) with “Actuator controls”.

Can anybody help me with this?

Thanks

2

I think the yaw increase that you see is the integrator winding up. You could try to reduce this effect by lowering the integral part of the yawrate control: https://dev.px4.io/en/advanced/parameter_reference.html#MC_YAWRATE_I

For the fact that in altitude mode, nothing happens until about 75% throttle should be expected, although it should be about 60%, so 50% is to stay at the current altitude and then a deadzone above it before it starts to climb.

3

Thanks for your explanation about altitude flight mode.
I’m changing the pid to follow your suggestion.

Thanks

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