Hello,

I'm testing some failsafe feature - THROTTLE Failsafe.

How configure:

1) You must configure you RX its failsafe mode. ie : you define all servo positions to a fixed value. (FrSky for example)

2) Concentrate yourself to define a value of your THROTTLE rx output in failsafe mode < THR_FS_VALUE (parameter in APM) Here THR_FS_VALUE = 990

3) Set in Planner FS_LONG_ACTN and FS_SHORT_ACTN = 1 for respective action in long failsafe and action in short failsafe

4) Test the failsafe on APM

The result :

First attempt (Short Faisafe Mode):

-You are in Manual mode and you lose a short moment (2s) communication between your plane and your TX

- THEN Circle mode is engaged (Apm short failsafe)

- You regain communication a short moment

- THEN Manual mode is engaged (End of Apm failsafe)

Etc....

Ok it works as descrided

But the issues are :

1) if the APM switches every second to an automatic mode and manual mode. You can enter in a vicious circle (switching modes) and loose control of your plane. -> Failsafe must be memorized

2) Many of RX have  failsafe enabled on all channel, you can't choose which channel is in failsafe mode. During the failsafe time all channels could take a fixed value different to the past TX control.

-> Circle mode degraded

If your rx failsafe setting was too old (you moved gravity center of the plane and it has a different setting for example), you might have an offset on servo control during Failsafe. -> Bad because manual mixing is engaged in the APM code. And circle mode will be degraded.

3) If case of "failsafe position" of your RX has for default mode Stabilize.

- You have control and you are in Stabilize mode and after you lose a short moment (1s) communication between your plane and your TX

- THEN Circle mode is engaged (Apm short failsafe)

- You regain communication a short moment

- THEN Manual mode is engaged (End of Apm failsafe)

But in case of the failsafe default mode IS NOT the current mode

For example

If failsafe position of your RX has for default mode Stabilize.

- You have control and you are in MANUAL mode and after you lose a short moment (2s) communication between your plane and your TX

- THEN Circle mode is engaged (Apm short failsafe)

- You regain communication a short moment

- THEN Manual mode is engaged (End of Apm failsafe)

- You loose communcation a short moment (2s)

- THEN Stabilise mode is engaged but not Failsafe.

Same issue for the Long Failsafe

Conclusion (in my opinion)

- 1) Failsafe action must be memorised (like a long failsafe)

- 2) In a failsafe event (ie THROTTLE < THR_FS_VALUE) a) all chanels must conserve their last value before the event. (mode channel too) b) Failsafe event SET a Failsafe mode memorised

- 3) In Failsafe mode memorised, the reset of the failsafe mode must be a mode changing (when failsafe event =0)  THEN the failsafe mode is reseted.

To discuss about...

Thank you