Loiter altitude stick response - not feeling god

[GoogleCodeExporter]

Arducoper APM2 AC 2.4.1 GIT 28feb, 3DR stock, 3S LiPo
What steps will reproduce the problem?
1. Engaging loiter mode with throttle stick at hover point
2. Using the throttle stick to command climb or descent
3.

What is the expected output? 
I expect proportional vertical response with a "harmonic" feel, much like would 
be expected when controlling altitude in manual throttle.

What do you see instead?
Too much stick movement is required to make it climb / descend. Dead band is 
far to wide and the vertical response to slow.
Bad side effect is if I command rapid descend in loiter mode, the throttle 
stick will be really low, thus if I want to bail out to Stable mode, throttle 
position is close to motors stopping.

My request is that the throttle stick altitude control comes with a lesser dead 
band, and a more firm response in the range outside the dead band. Big stick 
movement should NOT be needed to control climb / descent.
Adjust this and the altitude control will be perceived as more intuitive and 
harmonic.
Thanks / Tomas

Original issue reported on code.google.com by tomas.so...@gmail.com on 29 Feb 2012 at 1:06

[GoogleCodeExporter]

Hi Tomas, the deadband is easy to tuning inside the code... about firm response 
in the range outside the dead band i contact Jason for fix it!

Regards, Marco

Original comment by robustin...@gmail.com on 3 Mar 2012 at 9:22

• Changed state: Accepted

[GoogleCodeExporter]

In ArduCopter.pde, around line 1990:

static void
adjust_altitude()
{
    if(g.rc_3.control_in <= (MINIMUM_THROTTLE + 250)){
        // we remove 0 to 250 PWM from hover
        manual_boost = (g.rc_3.control_in - MINIMUM_THROTTLE) -250;
        manual_boost = max(-250, manual_boost);
        update_throttle_cruise();

    }else if  (g.rc_3.control_in >= (MAXIMUM_THROTTLE - 250)){
        // we add 0 to 250 PWM to hover
        manual_boost = g.rc_3.control_in - (MAXIMUM_THROTTLE - 250);
        manual_boost = min(250, manual_boost);
        update_throttle_cruise();
    }else {
        manual_boost = 0;
    }
}

Replace all "100" value with "250"... much much much better!!!
Try and write here your report.

Marco

Original comment by robustin...@gmail.com on 4 Mar 2012 at 4:12

[GoogleCodeExporter]

Hi Marco,
I will try this mod when I have opportunity, and I will report back.
Later on it might be advisable to have the release code include this 
adjustment, if we agree it makes flight control more intuitive. Cheers / Tomas

Original comment by tomas.so...@gmail.com on 4 Mar 2012 at 10:30

[GoogleCodeExporter]

Hi Marco,
I have been flying some flights and tested your code mod for vertical loiter 
control. (replacing 100 by 250 in the relevant code). Felt better, less dead 
band and more firm response.
BUT - now it was almost too sensitive, once out of the dead band. Especially 
when commanding descend, my quad came down a bit too fast. Maybe this can be 
improved by Alt_Hold PID tuning, maybe not. Another day I might try with 200 
instead of 250.

Original comment by tomas.so...@gmail.com on 6 Mar 2012 at 5:27

[GoogleCodeExporter]

I think this issue is fixed in newer versions

Original comment by Benny.Si...@gmail.com on 20 Jan 2013 at 10:39

[GoogleCodeExporter]

Issue closed. 
If you find this is an error please report it in the new issues list
https://github.com/diydrones/ardupilot/issues?labels=ArduCopter&page=1&state=ope
n

Original comment by Benny.Si...@gmail.com on 20 Jan 2013 at 10:39

• Changed state: Done