Re: [Paparazzi-devel] On Screen Display (Reto Buettner)

[Chris Gough]

I agree, a failsafe/MUX won't necessarily improve security, it's main
function is to comply with rules that require a flight termination
system that's independent from the autopilot. I don't know of any
legal rules like that in my jurisdiction, but it's certainly a rule
for the OBC, and googling "range safety plan" finds other situations
where it's a requirement too.

Chris Gough

On Thu, Aug 4, 2011 at 2:21 AM, Rui Costa <address@hidden> wrote:
> Yes, but for legal UAV's we have to improve the failsafe system. You are
> right, the failsafe board can also fail. But This board will has less
> probability of crash because has less code. Don't you think? It's just an
> ideia. I don't know if I'm right.
>
> For regulamentary purposes the authorities should claim for redudant safe
> systems.
>
>
> Best regards
> Rui Costa
>
> On Wed, Aug 3, 2011 at 1:12 PM, <address@hidden> wrote:
>>
>> Note that the Paparazzi autopilot has this failsafe MUX built into it.
>>
>> Why add another failsafe board (that could itself fail)?
>>
>> If the failsafe device fails then the aircraft would lose control.
>>
>> Better to keep things simple and stick to one board (Paparazzi).
>>
>> Paparazzi’s LPC2148/STM32 CPU’s have excellent watchdog circuits.
>>
>> FYI, Mark
>>
>>
>>
>> From: address@hidden
>> [mailto:address@hidden On Behalf
>> Of Rui Costa
>> Sent: 03 August 2011 14:58
>>
>> To: address@hidden
>> Subject: Re: [Paparazzi-devel] On Screen Display (Reto Buettner)
>>
>>
>>
>> Thanks for the informations.
>>
>>
>>
>>
>>
>>
>>
>> Best regards
>>
>> Rui Costa
>>
>> On Wed, Aug 3, 2011 at 10:56 AM, Chris Gough
>> <address@hidden> wrote:
>>
>> These links might also be of interest:
>>
>> http://www.acroname.com/robotics/parts/R306-RXMUX.html
>>
>> http://www.rcgroups.com/forums/showthread.php?t=360746&highlight=autopilot+mux&page=2
>>
>> My OBC team is having robust discussions about using the Millswood
>> device, stringing together some MUX chips, or using a CPLD/micro type
>> solution. Failing-over to a redundant autopilot is no benefit for the
>> OBC, the rules emphasise range safety at the competition site (flight
>> termination) over protecting the UAV from failure. But switching
>> between autopilots during flight tests might allow us to fly with
>> "riskier" configurations.
>>
>> Still arguing about it, nothing real to share (yet).
>>
>> Chris Gough
>>
>> On Wed, Aug 3, 2011 at 7:00 PM, Rui Costa <address@hidden> wrote:
>> > Great solution! Thanks for sharing. :)
>> >
>> >
>> >
>> > Cheers
>> > Rui Costa
>> >
>> >
>> >
>> > On Wed, Aug 3, 2011 at 8:56 AM, Reto Büttner <address@hidden>
>> > wrote:
>> >>
>> >> See:
>> >>
>> >> http://www.millswoodeng.com.au/failsafe_device.html
>> >>
>> >> Cheers, Reto
>> >>
>> >> 2011/8/3 Bernard Davison <address@hidden>:
>> >> > You'd have to have a separate path to control the servos.
>> >> > At the moment everything is going through the paparazzi flight
>> >> > computer.
>> >> > So if something in it crashes then the system will be left hopefully
>> >> > in
>> >> > a
>> >> > failsafe mode.
>> >> >
>> >> >
>> >> > On 03/08/2011, at 6:30 PM, Rui Costa wrote:
>> >> >
>> >> > Since we are talking on redundancy. Is there any way to have a sorte
>> >> > of
>> >> > an
>> >> > watchdog board that will change to an independent manual control of
>> >> > the
>> >> > aircraft if any paparazzy board crash was detected? Some kind of a
>> >> > relay/switch?
>> >> >
>> >> >
>> >> >
>> >> > Best regards
>> >> > Rui Costa
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > On Wed, Aug 3, 2011 at 8:09 AM, Reto Büttner
>> >> > <address@hidden>
>> >> > wrote:
>> >> >>
>> >> >> Hi Vladimir,
>> >> >>
>> >> >> the effectivity of redundancy measures depend very much on the
>> >> >> failure
>> >> >> mode. If the main Paparazzi board completely fails, you are right.
>> >> >> Then the plane is not steerable anymore, neither autonomously nor
>> >> >> manually and the plane crashes. The main Paparazzi board is a very
>> >> >> hard to avoid single point of failure. But if the main paparazzi
>> >> >> board
>> >> >> only fails partially (e.g. autonomous control loops not working
>> >> >> properly anymore), only the GPS, the IR sensors/IMU/INS/AHRS or the
>> >> >> serial data link fail, then the redundancy using FPV and a separate
>> >> >> OSD will save your aircraft.
>> >> >>
>> >> >> Cheers, Reto
>> >> >>
>> >> >> 2011/8/2 Volodymyr Khudyakov <address@hidden>:
>> >> >> >
>> >> >> > If Paparazzi fails, you simple fall to ground...
>> >> >> > All control you have from AP board and any OSD can help you.
>> >> >> >
>> >> >> > Sincerely
>> >> >> > Vladimir
>> >> >> >
>> >> >> > Date: Tue, 2 Aug 2011 15:21:47 +0200
>> >> >> > From: Reto B?ttner <address@hidden>
>> >> >> > To: address@hidden
>> >> >> > Subject: Re: [Paparazzi-devel] On Screen Display
>> >> >> > Message-ID:
>> >> >> >
>> >> >> >
>> >> >> >  <address@hidden>
>> >> >> > Content-Type: text/plain; charset=windows-1252
>> >> >> >
>> >> >> > The OSD of C?dric based on the Paparazzi data stream is great.
>> >> >> > Very
>> >> >> > compact and well integrated. Thanks for developping and sharing.
>> >> >> >
>> >> >> > For long range missions I prefer a separate OSD system for
>> >> >> > redundancy
>> >> >> > reasons. If Paparazzi fails you can complete the mission using FPV
>> >> >> > and
>> >> >> > OSD. If FPV and/or OSD fail you can complete the mission using
>> >> >> > Paparazzi.
>> >> >> >
>> >> >> > Cheers, Reto
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> > _______________________________________________
>> >> >> > Paparazzi-devel mailing list
>> >> >> > address@hidden
>> >> >> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>> >> >> >
>> >> >>
>> >> >> _______________________________________________
>> >> >> Paparazzi-devel mailing list
>> >> >> address@hidden
>> >> >> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Rui Costa
>> >> > _______________________________________________
>> >> > Paparazzi-devel mailing list
>> >> > address@hidden
>> >> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>> >> >
>> >> >
>> >> > _______________________________________________
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>> >> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>> >> >
>> >> >
>> >>
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>> >
>> >
>> >
>> > --
>> > Rui Costa
>> >
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>> > address@hidden
>> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>> >
>> >
>>
>>
>>
>> --
>> .
>>
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>> address@hidden
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>>
>>
>> --
>> Rui Costa
>>
>> _______________________________________________
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>> address@hidden
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>>
>
>
>
> --
> Rui Costa
>
> _______________________________________________
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>
>



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