Re: [Paparazzi-devel] CAUTION! RC input signs for roll/yaw reversed in 4.0_beta

[Felix Ruess]

Hi again,

we fixed some more sign issues in 4.0_beta, but unfortunately there is no way around changing the command_laws and/or the servos sections in your airframe files:

• change RC file so that RC value for roll (and yaw) is positive to the right
• if you have a delta wing: in airframe file, change command_laws right=elevator+aileron, left=elevator-aileron (swap signs before aileron)
• for convential aircraft, I would recommand to replace the above by changing min and max in the servo section (to keep left=roll, right=roll)
  
• if using AILERON_DIFF, don't forget to invert it in control laws (1 : AILERON_DIFF <-> AILERON_DIFF : 1)
  
• control gains are positive

The *_example airframes in the repository are updated accordingly.

Some internal commands (e.g. h_ctl_aileron_setpoint) are still reversed, but we will fix that. This doesn't affect end users as this is purely internal and doesn't require any configuration changes (is only annoying if you read the code or debugging displaying the commands).

Cheers, Felix

On Fri, Mar 16, 2012 at 2:21 PM, Felix Ruess <address@hidden> wrote:
> Hi all,
>
> to get rid of the weird sign changes for RC input we changed it to follow
> the standard aerospace axis conventions. It was really annoying because
> control, navigation, etc. follows the conventions, but for historic reasons
> only the RC input did not.
> See also https://github.com/paparazzi/paparazzi/issues/124 
>
> This change is now in 4.0_beta, so it means that you will have to change
> your radio control xml file to get a positive value when pushing roll stick
> right and a positive value when pushing yaw stick right!
>
> If you encounter any issues, please report them... and don't forget to do
> proper pre-flight checks (as you should always) before going into the air
> ;-)
>
> Cheers, Felix