What caused my Failsafe

ArduCopter Copter 3.1
1

HI All:

I have been flying in Auto successfully but at times Im hitting a FAILSAFE and not sure why. I have my failsafe set to Continue Mission so it always completes successfully. I am attaching my logs to see if anyone can explain to me what is going on. I am seeing a RADIO ERROR [approx 17:45] which I am not sure if its the 3DR Radio or the transmitter being referenced.

Thanks,
Maurice

2

The dataflash log might be more helpful here than the Tlog. The dataflash logs are certainly easier to review for issues.

3

Sorry… See logs attached.

Regards,
Maurice

4

It looks like you had two RTLs, one during your Auto mission, and another one later that looks like you commanded it. So let’s ignore the second one and look at the first.

On line 44898 you lost your ground control station’s telemetry signal. That gave you your 2-2 error code. On the next line, 44899, RTL is invoked.

In your parameter file, your FS_GCS_ENABLE is set to 0, which is disabled. I suspect you need to set it to 2, which is “Enabled Continue with Mission in Auto Mode”. You did have your FS_THR_ENABLE set to 2, which is also continue the mission, but that’s only for a loss of the throttle signal (which you did lose quite a number of times, BTW). I would think having the FS_GCS_ENABLE set to disable wouldn’t have been a problem, but it looks like that’s the case if you are using a ground station.

Give it a try and see if that takes care of it.

5

I will set the GCS Failsafe parameter and see what happens. I thought (as you said) that no failsafe would have been triggered if it was set to 0. Can you tell me which lines indicate a throttle signal loss.

Thanks,
Maurice

6

The throttle failsafes occur at lines 25614, 33140, 44900 and 45814.
It’s easy to view these yourself. Open your log in Mission Planner and right click on the header row for the columns. A drop down menu appears allowing you to filter the data table for various items. Select “ERR”, and you’ll see all the failsafes, both when they started and when they ended.

Here’s a much more detailed version of how to do it from the Wiki.

7

Thanks Otherhand I actually figured it out last night and went through the WIKI. The behaviour of the FAILSAFE is as documented. I had it set to continue Mission and it did just that. I was doing some further tests and realised that if FAILSAFE is disabled then if there is a signal loss the error is not logged. It would be useful if there was an option to log these events even if no action is taken so that one could analyse these errors before deciding if a FAILSAFE should be enabled and therefore what appropriate action.

Regards,
Maurice

8

I am fairly new to APM, but you should be able to see signal loss by looking at THR_In and THR_out. They should track each other fairly well. A sudden drop to a very low PWM value (or to the PWM value you set on your Tx/Rx failsafe) or change in your THR_in would indicate a throttle failsafe, and is how you can see the event if you suspect it might have happened.

9

Britdavis,

I am using a Spektrum Satellite Receiver with Pixhawk and it actually doesn’t change the throttle input/output when I turn my radio off. I think the FAILSAFE is triggered if no RC data is received for 2 seconds and I’m not sure where in the log that activity is logged.

Regards,
Maurice