the vagaries of safe mode ...

[powerlord]

Need a bit of help here please:

Got my new arducopter flying awesomely. stable as could be. all happy bunnies.

I set my v8frII to activate channel 5 to flight mode RTH when it is in safe mode (it also zeros throttle though..)

I tested this connected to mission planner, and switching the tx off activates RTH mode.

I had the safe mode stuff in mission planner not enabled - since I';m just using the v8frii directly to do it.

I dunno - maybe in hind sight I should have let it activate from APM based in the low thottle?

Anyhoo, trying it out for first time from 50 feet or so - motors stopped. plumetting quadcopter. 2 arms smashed, one ESC dead. arse.

Now, all I can think of is that while programing the safe mode settings into the v8frII i took the liberty of setting the throttle super low too (to 975 - i.e. less than the usual minimum). I figured I then had the option of using the APM safe modes later if I wanted.

However the manual for APM says thottle isn';t used for RTH so it going super-low on activating flight mode RTH should not have mattered surely ?? Also - as I say I had the APM safe mode stuff disabled at this point.

So any idea what I did wrong ? I do a similar thing with my NAZA (programming the fr8 to activate RTH on tx down) and that works great.

here';s the death dive:

quadcrash on RTH activation

I will say this - I';m impressed that the brushless gimbal managed to keep itself level all the way through the quad flipping through 180 degrees....

humph.

stu

[Gaza07]

Ouch its never nice when you crash, I have yet to set up failsafe 

[Balders]

Video didn';t work here mate.

[optiplex]

if u mean FAILSAFE (not safemode) otherwise im not sure what u mean
but ... if its indeed failsafe try this, i set my failsafe according to this and works great

https://code.google.com/p/ardupilot-mega/wiki/APM2xFailsafe

[powerlord]

if u mean FAILSAFE (not safemode) otherwise im not sure what u mean
but ... if its indeed failsafe try this, i set my failsafe according to this and works great

https://code.google.com/p/ardupilot-mega/wiki/APM2xFailsafe

failsafe = safemode yes.

Sure, I can try this, but the point is - RTH does not seem to be working just now. Since that is what I am currently activating (via the TRANSMITTER failsafe) rather than via APMs.

stu

[firey1]

I could be wrong so dont shoot me

But using the radio fail safe you need to set all parameters for loss of signal
so to have a RTL as loss of radio
you will need to have the switch for RTL on as the direction command
throttle stick set to right level = speed of motors you want so it keeps flying
then bind theses settings to your fail safe

If all you did was select RTL switch with throttle down then the commands sent on loss of TX will be
RTL with no throttle hence the drop 

[powerlord]

No I gotcha - my first thoughts but the docs says throttle is ignored completely in Rth mode

[firey1]

Return To Launch (RTL) mode
This simply returns the aircraft to you (your launch position) and circles overhead. Technically, RTL is a macro that sets home as the next waypoint and enables Loiter mode.

You can also "nudge" the aircraft manually in this mode. Throttle "nudging" occurs if the throttle stick is in the top 1/2 of the range and moves the airspeed or throttle setpoint up towards the upper limit proportional to the stick';s position in the top 1/2 of the range. Normally you should have the throttle stick in the lower 1/2 of its range when using any "auto" mode.

[powerlord]

Return To Launch (RTL) mode
This simply returns the aircraft to you (your launch position) and circles overhead. Technically, RTL is a macro that sets home as the next waypoint and enables Loiter mode.

You can also "nudge" the aircraft manually in this mode. Throttle "nudging" occurs if the throttle stick is in the top 1/2 of the range and moves the airspeed or throttle setpoint up towards the upper limit proportional to the stick';s position in the top 1/2 of the range. Normally you should have the throttle stick in the lower 1/2 of its range when using any "auto" mode.

oo hello. that looks more likely to be the problem then. what page were you looking at ?

I was looking here:

http://code.google.com/p/arducopter/wiki/AC2_RTLMode

that seemed to suggest that all stick movements were totally ignored until another flight mode was engaged ??

stu

[firey1]

I think its the confusion between the mission planner fail safe and using the TX fail safe

in mission planner fail safe it uses the no throttle setting as its initiator and looks for 1.5 secs before engaging RTL and then has set parameters for throttle level

when using the TX fail safe for RTL all parameters need to be set for it RTL and throttle level  manually as you are only invoking a standard auto flight mode

in  auto flight mode you can control the craft with stick movements 

[powerlord]

hmm ok - but the page i referenced WAS the standard RTH flight mode.

it is that that I am activating with my tx/rx failsafe.

perhaps I confused the discussion by talking about mission planner failsafe - as i say - it was disabled. sure - I had set the tx/rx throttle to drop to 975 as well as the channel 5 to change flight mode to RTH, but this should have been irrelevant to it as i';d kicked it into RTH anyway.

perhaps there is some sort of loop whereby the flightmode change is ignored if the throttle goes down low at the same time ?


stu

[Leigh]

Bugger, stu.  Seems like today is the day for multirotors and helicopters to crash - we had 3 go down today at our Heli fly-in in Broughshane (my tricopter included)!

One member';s quadcopter had an APM which was struggling to RTL in the wind (and failing badly) so the pilot, who is a very skilled one at that, switched it to manual to fly it back but as soon as he tilted into the wind, one propellor snapped and what followed was a whirly-gig spiral death dive into the ground. 

Another member was flying their large nitro heli and got a bit too close to the ground and a downward gust of wind pushed his tail into the ground and the poor thing snapped itself into the ground like a mousetrap.

My new tricopter was the third victim, but I';ll save that story for a new thread and video.

[firey1]

"Quote"
Now, all I can think of is that while programing the safe mode settings into the v8frII i took the liberty of setting the throttle super low too (to 975 - i.e. less than the usual minimum)

so when the apm went into RTL auto mode(which is different to mission planner RTL) it saw a dead throttle stick and shut down motors

the throttle setting you put into the TX ( super low)  is only used by the mission planner as its trigger to initiate the misson planner fail safe RTL which has inbuilt parameters for throttle setting   

[Leigh]

My new tricopter was the third victim, but I';ll save that story for a new thread and video.

as promised: www.multi-rotor.co.uk/index.php?topic=2824.msg22468

[sevet]

I would suggest setting the RX failsafe to RTH, and so, only on RX fail it will do a safe mode of the APM to RTH (which is more rare)