Re: [Paparazzi-devel] simultaneously using two autopilot

[Drone Savant]

My understanding is that Tridge was able to successfully use a Dual APM setup 
in one of the previous years at a UAV competition. Does anyone know any of the 
detail there? 
-KF

On Mar 27, 2013, at 5:01 PM, refik <address@hidden> wrote:

> 
> Hello,
> 
> 
> Thank you very much for all of your answers. I am convinced to use a single
> autopilot system. However, there are still some question marks.
> 
> 
> I left my umarim_lite_v2 board open for 2-3 days. When I came back, the gyro
> was not working. I am not sure about why it was burned, maybe it was heated
> a lot and burned, or I burned it with ESD. Anyway, if it burns again in a
> long duration flight, it will be a very big problem.
> 
> Autopilots are reliable, but maybe the IMU components are sensitive and
> fragile. I will test my umarim and IMU's on the ground for several days
> again. If it burns again, than I will use a different autopilot or IMU. 
> 
> If it is possible, we can connect two IMU's to a single autopilot. Also, we
> can connect two GPS and two modems.    
> 
> Cheers,
> Refik
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Wed, 27 Mar 2013 11:55:17 +1100
> From: Chris Gough <address@hidden>
> To: address@hidden
> Subject: Re: [Paparazzi-devel] simultaneously using two autopilot
>       systems for reliability
> Message-ID:
>       <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> Hi Refik
> 
> In my opinion it's difficult to make a the system more reliable by
> adding complexity. If you have an additional component choosing which
> autopilot should be in control, that device has to be more reliable
> than the autopilots otherwise the system will be less reliable than a
> single autopilot. The autopilots are very reliable, so it's a hard
> ask.
> 
> In the Outback Challenge competition we were required to have an
> independent failsafe device. Initially developed a "failsafe/mux"
> device that with a "failover feature", it would try falling back to
> the a spare autopilot before triggering a failsafe (deliberate crash).
> We abandoned that because we felt it was less secure than having a
> simpler failsafe and a single autopilot. To many wires, an immature
> component on the critical failure path, more complexity than
> absolutely necessary. I'm not convinced the failsafe made the system
> any more secure either, but it was necessary because of the rules of
> the competition.
> 
> Redundant communication links do make sense if link reliability is
> important in your application. Any given link can fail for a number of
> reasons, spatial and spatial diversity of multiple links probably adds
> more than the additional networking component takes away.
> 
> For redundant GPS', I suppose the information is there to chose "the
> best of many" one but my guess is that the benefit would be marginal
> compared to single, well installed GPS (good location, good cable
> management).
> 
> I don't know about redundant IMUs.
> 
> Split control surfaces (redundant servos) are a common precaution on
> larger airframes.
> 
> Chris Gough
> 
> 
> On Tue, Mar 26, 2013 at 7:21 PM, refik <address@hidden> wrote:
>> Hello,
>> 
>> In paparazzi, is it possible to use two complete autopilot systems for
>> reliability ? (each system includes GPS, imu, transmitter and autopilot,
> if
>> one of the systems is gone, the system automatically switches to other).
>> 
>> If it is not possible currently, I think that it will be a good choice to
>> implement.
>> 
>> 
>> We will try to fly an aircraft for 24 hours within 20km, therefore we will
>> need a reliable autopilot. What configuration (autopilot, imu, Gps and
>> modem) do you suggest to use?
>> 
>> Cheers,
>> Refik
>> 
>> 
>> _______________________________________________
>> Paparazzi-devel mailing list
>> address@hidden
>> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
> 
> 
> 
> -- 
> .
> 
> 
> 
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