Rescue parameters based on prop size

[cedar crow]

Hi, while testing the 4.5 rescue on different sized quads, I noticed that some parameters are suitable for a 5" but not optimal for smaller or larger quads. I understand that prop size is a simplification since significant differences exist between, for example, a 3.5" cinewhoop and a 3.5" freestyle drone, but it may be a good starting point.

Parameters that need quad-specific settings:

Ascend rate (meters/second)
Return ground speed (meters/second)
Descent rate (meters/second)

I have access to 3", 5", and 7" quads, plus friends with 10" quads. The idea is to find the optimal settings based on prop size and share them with the community, either by reporting them in the wiki (documentation) or by creating presets for the Configurator.

Any suggestions or ideas?
Thanks, Patrick

[bronze lance]

there have been suggestions to put some of these into profiles so you can change them if needed by switching profiles, but for now, rescue parameters are 'general' values.

Just as some quads need different PID tune, different AG settings, different feedforward etc, so it is that different quads need different GPS settings.

A PR to update the GPS rescue wiki that added a table of suggested Rescue PID settings for different kinds of quads would be a great idea. A discussion could be started in the public development 'documentation' channel. It may take a bit of time to agree on suitable settings 🙂 everyone has their own ideas, and even 10in quads vary a lot one to the other 🙂

It's fine to make Presets also, that's a bit more complicated than just adding some documentation though. If we did reach a good consensus on suitable values, then we can put them into official presets after a period of time as 'custom' presets.

The defaults should work OK for typical 5-7in GPS type quads, if not, we should make a firmware PR to alter them to values that more reliably achieve what is intended.

[leaden stream]

As a data point for you, I use these setting for a porky 6" with 4S batts. I sometimes fly with 1800maH lipos, sometimes with 300gm, 4200maH li-ion. set gps_rescue_ascend_rate = 700
set gps_rescue_ground_speed = 1100
set gps_rescue_max_angle = 40
set gps_rescue_imu_yaw_gain = 15
set gps_rescue_descent_dist = 30
set gps_rescue_descend_rate = 100
set gps_rescue_disarm_threshold = 23
set gps_rescue_throttle_min = 1125
set gps_rescue_throttle_max = 1750
set gps_rescue_throttle_hover = 1350
set gps_rescue_yaw_p = 25