RC Failsafe Time Delay

edwardme · August 29, 2019, 2:45am

Hi all,
Currently, I’m experiencing some fail-safe triggering on RC brown outs. I’m looking for a way to give the FC a set number of seconds until it actually performs the failsafe. Example useful scenario:

When flying in Auto, I don’t want to trigger an RC Failsafe unless my RC Link has been down for 10 seconds.

Maybe this is already a feature but I couldn’t find literature on it.

Thank you!

Eosbandi · August 29, 2019, 11:32am

It is hardcoded, defined by the
#define FS_RADIO_TIMEOUT_MS 500 // RC Radio Failsafe triggers after 500 miliseconds with No RC Input
line in config.h
To change it you have to recompile the code.

sergbokh · August 29, 2019, 12:30pm

I did something similar as a custom feature, actively using that on my copter:

github.com/ArduPilot/ardupilot

Copter: Do a Brake before RTL for a radio FS event

opened 09:03AM - 12 Sep 18 UTC

SergeyBokhantsev

Enhancement

It is a common case for FPV fliers that radio contact may be lost for a short pe…riod of time. For example you could succinctly turn your RC antenna into a wrong position etc. The RTL engages instantly in that cases. That is not very comfortably and makes no sense if your connection restored after one or two seconds. Another concern is user have to re-switch fly mode to cancel RTL and set his previous mode. This requires for additional actions and could lead to a human mistake. ### Feature request 1. Copter to do a short pause (goto Brake mode for 3-5 seconds) on radio failsafe event before engage the RTL procedure. 2. If radio contact will be restored while that pause and user moves pitch/roll stick above some threshold then a previous fly mode should be set. 3. This feature shall be only applicable to an intelligent fly modes: Loiter, AltHold, PosHold etc. So the another criteria for [2] is the throttle level that must be near mid level to cancel RTL. 4. Add new setting (flag) to select the fly modes this feature will be enabled for: - 1 - enabled for Loiter - 2 - enabled for AltHold - 4 - enabled for PosHold **Platform** [x] Copter

edwardme · August 29, 2019, 4:58pm

Does anyone know someone who could change the FS_RADIO_TIMEOUT_MS to a modifiable parameter? I think this would be useful. @rmackay9

Arjun_BJ · August 30, 2019, 5:36am

I would be very careful changing just FS_RADIO_TIMEOUT_MS as if I understand correctly, this would effect all flight modes which would be a very bad thing flying in manual modes. Proceed with caution.

sergbokh · August 30, 2019, 12:02pm

I’m also think so. I believe copter will just execute last received RC channel values during increased FS_RADIO_TIMEOUT_MS period. Even in smart modes like Loiter, this could behave very bad if the last RC command was to descend etc.

edwardme · August 30, 2019, 9:40pm

I agree, but perhaps this could be changed to depend on the flight mode. i.e: if in Auto, it wouldn’t affect it.
This would be especially good for OEM’s relying on autonomous flight modes

Eosbandi · August 30, 2019, 9:42pm

I think you guys should wait a little bit till 3.7 is come out, with onboard scripting you can do whatever you want regarding to failsafe without modifying the actual FC code.