Improvement of velocity command in axis z

Hello guys,
I have a question about velocity command in axis z in Guided mode.
I’m using ArduCopter4.1.1
when I use the velocity command in axis z, the desired command has got a lot of delay and it doesn’t get steady in a certain time.
You Know, I’d like the desired velocity command to be as sharp as
possible and to be applied in step command; So that no smoother slows it down.
Do you have any solution for that?

I’d really appreciate it if you answer me ASAP.
here is my log:

Tune the Z-axis PID . Have you read Tuning Process Instructions — Copter documentation ?

Yes, I have read But Which part should I tune?
Do PID parameters also affect the desired value?( which params?)
I like to see the control diagram block implemented to execute velocity commands in axis z in Guided mode. can you help me, please?

You can experiment with PSC parameters, especially the ones with Z axis.

You should tune all of them, and in the very end there are tuning instructions for the altitude controller.
But first you need to tune the others.

Read it, and execute it without skipping a single step. Lots of people do skip steps and then complain that it does not work. Do not be one of them!!!

Thanks for your help

But first update to ArduCopter 4.1.3. Do you have any reason not to use the stable version?

No, l haven’t any reason.
Is there any important reason that l have to update it?

The Z controller has been improved and some critical bugs fixed. The release notes provide details.