LibrePilot Forum
Users => Vehicles - MultiRotors => Topic started by: 3dprintingwa on May 22, 2016, 04:48:26 pm
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Hi Guys
running CC3D with a X4R in 280 size quadcopter, arming through channel 8, motors always spinning when armed and AlwaysStabilizeWhenArmed enabled.
Somehow that X4R doesn't like to set failsafe, all it does is no pulse, meaning all channels go high, same as unplugging RX altogether.
So I believe the CC3D should take that as a failsafe, drop out of the sky situation, however, the motors reduce throttle to minimum output values, but keep spinning and still respond/ correct rate.
Is this expected behavior ( ignoring my X4R not doing its own proper failsafe drill for the moment), as I find that fairly dangerous and would like to see a dead copter once failsafe is triggered?
Or did I miss something in my setup?
Any help is much appreciated
Cheers Phil
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All of my x4r sb recievers are set to no pulse. Which is exactly that, no pulses. It shuts the copter down and give it no signals of any kind.
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Could you please check how that looks in GCS ( no bars or full bars ) ?
Do you know if there are any settings in LP that change fs behaviour ( eg slow land vs disarm)?
cheers
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GCS/cc3d have their own failsafe. Taranis/x4r also have their own. Need to set both. System tab at bottom I believe. I'll check and get back to you in this thread
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that would be great, thanks.
The question remains: does copter set 0 throttle or disarm, even in flight, when LP failsafe is triggered?
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I too am trying to get to the bottom of a failsafe issue. A couple of weeks ago I deliberately switched of my TX to see if the failsafe would work. Unfortunately my quad just fell out of the sky and did not ReturnToBase which was the failsafe flight mode setting. My setup is slightly different in that I am using a Revo and not a CC3D. I am using a FrSky X4R-SB receiver which is connected to the main port of the Revo and configured for S.Bus.
I've tried to set up the failsafe settings on my X4R-SB using both the Taranis TX and also using the F/S on the RX. In both cases, I've set throttle, yaw, pitch and roll to neutral positions, and my flight mode switch to 6 which is the ReturnToBase flight mode. In both cases, when I switch of the TX, all remote control inputs go to their maximum values, in my case 1811. For the flight mode this is OK because it is position 6, ReturnToBase, so should hopefully do this on loss of signal from the transmitter. However, that didn't appear to be the case a couple of weeks back.
I should add to this that the ReturnToBase does actually work OK. When I switch my TX to position 6 (ReturnToBase flight mode) my quadcopter does return to where it took off, a set hight above ground level.
I've also tried setting the RX to no pulses on loss of signal (not sure what this means for S.Bus), but again, no different from before when the TX is switched off.
Another test I carried out a short while ago was to disconnect the S.Bus line from the Revo when the TX is on. The effect was the same, all channels on the 'Remote Control Input' tab go to maximum (i.e. 1811) despite the failsafe setting on the 'Failsafe Settings' tab being neutral, apart from the throttle which is set to -100%. Even changing the failsafe flight mode to a value other than position 6 does not seem to get reflected when S.Bus is disconnected.
Firstly, I am not convinced my RX is doing what it is supposed to on S.Bus when supposidely configured to send failsafe channel values to the Revo. I need to hook up a logic analyser to explore this further.
Secondly, I am not convinced the failsafe is working on the Revo for the S.Bus input. Probably failsafe on Revo does work OK for other receiver configuration modes such PWM and PPM, but I haven't tried, but I am assuming others have and use without problem.
I am using a version of 'next' that I compile the beginning of April. Looking to recompile and try with a later version of 'next' once the compile issue has been resolved, reported in a different thread.
Is anyone else using S.Bus and failsafe without issue? If so, any clues as to what I may be doing wrong?
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I'm running a Taranis with x4r-sbus. 4 different copters all running sbus. All set to no pulses and every time I switch off the radio all copters shut down.
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I'm running a Taranis with x4r-sbus. 4 different copters all running sbus. All set to no pulses and every time I switch off the radio all copters shut down.
When you say 'all copters shut down', do you mean the CC3D shuts the motors down and the copter falls out of the sky like I have experienced?
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Fall out of the sky is the default failsafe throttle setting, -100 (zero throttle). That's the safest thing for people in the area since the props that can cut someone are no longer spinning under power. You said "throttle which is set to -100%" so it should fall out of the sky. It probably is going into RTB mode but with zero throttle that doesn't work too well :)
Looking at the input tab just shows what it's reading from the receiver. The settings on the failsafe tab show what is fed into the FC when failsafe is triggered. If you set throttle on the failsafe tab to some value that will keep the bird in the air RTB may work but that's not really recommended for safety reasons.
The problem is now you have a quad you've lost radio control of with the engines running. If it just flew out of range you might be able to regain control but if the transmitter died or a wire came loose you could have a big problem.
Fall from the sky is also good if home/base wasn't set properly and the quad is flying off into the sunset. Better for it to drop to the ground at the limit of radio range than to fly till the batteries run out trying to get to some "base". Or you can turn off the transmitter and trigger failsafe if it starts to fly away.
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Yes all of my quads are set up to fall from the sky if they failsafe. Maybe a 3 second delay to see if it regains signal but that's it nothing more.
"Controlled landing" failsafe is not a good idea. It's better to crash and rebuild, than chop somebody up with your props. "Controlled land" and it tips over or gets stuck in a tree, then the motors and escs are going to fry trying to controlled land. Just cost more money than if it would of just broke an arm or something.
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Thanks hwh for the explanation of the failsafe settings and RC Input tab. Thanks too NicholasDavid for confirming what you meant by 'shut down'.
It would appear that my copter behaved correctly then on loss of TX signal, power was cut to the motors due to the default failsafe throttle setting of -100% and my copter fell out of the sky. Your thoughts on why this is the best failsafe option also make good sense.
In certain flight modes, such as ReturnToBase, PositionHold and AltitudeHold, I thought the throttle setting on the TX had no effect and therefore would similarly have no effect in the failsafe settings if one of these flight modes were to be selected as a failsafe option. I haven't tried completely cutting the throttle in one of these flight modes so don't know for sure, although I do know small adjustments of the throttle up and down around the midway position has no effect. This is why I assumed my copter would ReturnToBase on failsafe.
On the 'Remote Control Input' tab it would be helpful if a warning was displayed to show loss of signal from the RX when this condition occurs. It may be that the warning should be on a per channel basis although just a general warning would be good too. The reason I suggest this is because I thought the full scale values were being supplied from my RX when the TX was switched off. However, I do see if I view the 'System Health' table on a different tab that the I/O 'Input' field is orange and the below message is given when you click on it:
RC Input: Warning
One of the following conditions may be present:
* System is in failsafe mode
* Failed to update one or more of the accessory channels
Questions I have concerning the above warning are:
1) What conditions can result in the system entering into a failsafe mode in addition to loss of signal from the RX?
2) The second bullet under conditions only talks of accessory channels. Surely this applies to all channels, not just the accessory channels?
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I still haven't figured out my initial problem.
So it is normal for all bars to show max value, which means my RX is definitely in FS mode, so should be Librepilot.
But since I have AlwaysStabilizeWhenArmed enabled, motors spinning when armed and arming is done via switch, copter stays live and only goes to idle and keeps stabilizing, it does not switch off the motors ( ie disarm )
Could someone please confirm if there/where there are settings to change this behaviour?
cheers
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But since I have AlwaysStabilizeWhenArmed enabled, motors spinning when armed and arming is done via switch, copter stays live and only goes to idle and keeps stabilizing, it does not switch off the motors ( ie disarm )
Using 15.09 ?
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yes 15.09 off the shelf
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Using the 15.09, AlwaysStabilized is always active, so no way to select a flightmode or change any switch state in failsafe values.
The disarm occurs after a timeout, defined in Arming tab settings. Timeout only occurs if Throttle is low.
You should not want a instant in flight disarm, if quad go into failsafe maybe you can regain Rc link one second later and return to base, instead of falling from the sky, disarmed...
Next release allow ASWA on a switch, and failsafe settings exposed in Gui.
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Thanks for clarifying that. It makes things clear; and that's why I call it a safety concern.
Do you know when the new release will come out?
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Every day that is asked, the answer is "2 weeks". :)
Let me say some things about failsafes.
- there are 2: one in the RC and the other in the FC
- the RC failsafe works differently in different brands, and even works differently depending on whether the transmitter has been switched on since the receiver was powered up
- you need to research and test your RC failsafe to make sure you understand it
- it is required that you understand both failsafe systems
- the FC failsafe only takes over if the RC system stops sending pulses (or generally stops sending signal to the FC)
- the default for the FC failsafe is to stop motors and drop from the sky
- the FC failsafe can be set to go to any flight mode switch position AND ALSO has an associated set of control stick positions.
- RC failsafe may do any of these depending on brand and setting:
-- none (always stops the signal so the FC failsafe always takes over, safe, use FC failsafe)
-- go to previously selected position (if the receiver has "seen" the transmitter to get these values, and then the transmitter goes away for some reason, else don't send pulses, generally this RC failsafe needs to be programmed to go to a specific flight mode switch position and the FC failsafe is unused)
-- always maintain the last set of received stick positions (unsafe, this one is a fly-away waiting to happen as you can imagine)