A fail-safe or fail-secure device is one that, in the event of a specific type of failure, responds in a way that will cause no harm, or at least a minimum of harm, to other devices or danger to personnel.
Taking this definition as a start point, drones, obviously, also needs security measurements. You could configure Erle-Copter to enable failsafes. In this section, we will explain how to activate some of them (the most meaningful ones).
Note: As user might not have GPS, this section will show how to setup failsafes using land mode.
Erle-Copter supports Return-To-Launch/Land in cases where contact between the Pilot’s RC transmitter and the flight controller’s receiver is lost.
If enabled and set-up correctly the radio failsafe will trigger if:
Follow the next steps to enable it:
Make the next tests in order to verify is working fine:
Notice that the value of the throttle is lower than the minimum value (~1053) when the RC is on and that Erle-Copter has changed to Land mode.
Erle-Copter supports the activation of Battery based failsafe. Our Power Module enables battery monitoring. Right now (19-03-2015), battery voltage reading is supported in the latest Autopilot. Download the latest binaries from our repository!
Thanks to this reading, the user could know the battery voltage using a GCS.
This failsafe permits to you to minimize the risks of having a sudden death of Erle-Copter and enables a better use of your LiPo batteries.
If enabled and set-up correctly the battery failsafe will trigger if battery voltage drops below the threshold voltage determined (10.5v by default).
Also notice that if you try to arm Erle-Copter having a lower battery voltage than the trigger threshold one, an low battery error will show up (in the GCS in case you are using it).
Note: The use of a voltage sensing Power Module is mandatory!
Note: We are working on having current measurement, this will be used to establish current based failsafe.
Once you have activated the failsafe, you could check that you cannot arm Erle-Copter. Follow the next steps:
Don’t forget to restore desired low battery voltage value again!