# Throttle is not working in altitude

**URL:** <https://discuss.px4.io/t/throttle-is-not-working-in-altitude/9486>\
**Category:** Flight Testing & Log Analysis\
**Created:** [February 4, 2019, 8:27pm UTC](https://discuss.px4.io/t/throttle-is-not-working-in-altitude/9486 "2019-02-04T20:27:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![alessio.zatti](https://discuss.px4.io/letter_avatar_proxy/v4/letter/a/9de0a6/32.png) [@alessio.zatti](https://discuss.px4.io/u/alessio.zatti)\
**Post date:** [February 4, 2019, 8:27pm UTC](https://discuss.px4.io/t/throttle-is-not-working-in-altitude/9486/1 "2019-02-04T20:27:39Z")

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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](https://logs.px4.io/plot_app?log=d29ca377-61e3-42f2-8628-a265cc935f32)  
Compare the graph “manual control inputs” (throttle line) with “Actuator controls”.

 ![](https://discuss.px4.io/uploads/default/original/2X/1/147c87f7c569988af528d40e15ad180111b4e27c.png)

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](https://logs.px4.io/plot_app?log=1f9e1f64-daf9-4dd4-adc9-4cb4807140f0)

 ![](https://discuss.px4.io/uploads/default/original/2X/9/9c69e2b10e0014d127f593bfb08e15014818d99e.png)

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

Can anybody help me with this?

Thanks

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**Author:** ![JulianOes](https://discuss.px4.io/user_avatar/discuss.px4.io/julianoes/32/30_2.png) [@JulianOes](https://discuss.px4.io/u/JulianOes)\
**Post date:** [February 5, 2019, 8:45am UTC](https://discuss.px4.io/t/throttle-is-not-working-in-altitude/9486/2 "2019-02-05T08:45:26Z")

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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](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.

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**Author:** ![alessio.zatti](https://discuss.px4.io/letter_avatar_proxy/v4/letter/a/9de0a6/32.png) [@alessio.zatti](https://discuss.px4.io/u/alessio.zatti)\
**Post date:** [February 6, 2019, 5:27am UTC](https://discuss.px4.io/t/throttle-is-not-working-in-altitude/9486/3 "2019-02-06T05:27:46Z")

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

Thanks