Long Range Flying Wing

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Long Range Flying Wing

Reto Büttner
Hi guys

Last Saturday we achieved a nice long range flight over 125 km with a small UAV:

Flying Wing, 140cm wingspan, 2kg, 75 km/h, 2h endurance. See:

http://www.youtube.com/watch?v=nKf566KVfMo

We flew with our old and proven IR sensors, as we were not satisfied
with the ArduIMU. The experience is that over land everything work
fine, but along the shoreline (and fully over water) the control
characteristics degrade. Has someone made similar experience with the
IR sensors? Our next try will be the IMU SparkFun SEN-10121.

The data link using Maxstream 9XTend was mediocre. We had mostly
pretty good downlink (position, PFD, voltage, etc.). But the uplink
(repositioning of waypoints, new flight task, etc.) didn't work. With
the XBee we never had this issue. Has some made similar experience
with the 9XTend and knows how to fix this issue?

Cheers, Reto

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Re: Long Range Flying Wing

Chris Efstathiou
Congratulations thats quite an achievement so please give us some more info!
I use the 9xtend with a joystick at 115200 and the up link now works fine.
I had similar problems but i solved them using the polled mode.
Was the plane always under power or you also used gliding?
What battery voltage and capacity did you used (3s, 4s etc) and what motor?
I am building a similar plane right now using the X8 as a test bed
Chris




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Re: Long Range Flying Wing

Reto Büttner
Hi Chris

Thanks. Here some technical data of the power chain:

Motor and Control: Boost 25 + Regler XC30 (reused components of our
old Bormatec MAJA)
Prop: 9x9
LiPo: 3S 10'600mAh TP ProLite G6 25C

I am operating the 9XTend at 9600 baud. I was expecting better range
than at 115k. The polling mode? I have to check on that. Unfortunately
even using high gain antennas we don't get the expected range. What
range do you get with 115k using what antennas?

We were always under power, no gliding, no use of updrafts. That would
be a very interesting task, some already have done using other
autopilots. Or has someone in Paparazzi?

The X8 is a nice plane. We were considering it as well. For ultimate
performance of a flying wing you should have a look at the race guys,
like:
http://www.franz-josef-ney-online.de/Fotos/zezehn.JPG
http://www.franz-josef-ney-online.de/Fotos/F5B-2011-Ney.jpg

Cheers, Reto

2012/4/30 Chris <[hidden email]>:

> Congratulations thats quite an achievement so please give us some more info!
> I use the 9xtend with a joystick at 115200 and the up link now works fine.
> I had similar problems but i solved them using the polled mode.
> Was the plane always under power or you also used gliding?
> What battery voltage and capacity did you used (3s, 4s etc) and what motor?
> I am building a similar plane right now using the X8 as a test bed
> Chris
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>

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Re: Long Range Flying Wing

agressiva
Hello friends ...
talking about planes ... here is a pic of my BIG FLY WING.
I made it from scratch.
Its 1.8m wingspan.

i have plan to put 3d gimbal (roll,tilt,yaw) and 1km laser range finder



> Date: Mon, 30 Apr 2012 19:45:02 +0200

> From: [hidden email]
> To: [hidden email]
> Subject: Re: [Paparazzi-devel] Long Range Flying Wing
>
> Hi Chris
>
> Thanks. Here some technical data of the power chain:
>
> Motor and Control: Boost 25 + Regler XC30 (reused components of our
> old Bormatec MAJA)
> Prop: 9x9
> LiPo: 3S 10'600mAh TP ProLite G6 25C
>
> I am operating the 9XTend at 9600 baud. I was expecting better range
> than at 115k. The polling mode? I have to check on that. Unfortunately
> even using high gain antennas we don't get the expected range. What
> range do you get with 115k using what antennas?
>
> We were always under power, no gliding, no use of updrafts. That would
> be a very interesting task, some already have done using other
> autopilots. Or has someone in Paparazzi?
>
> The X8 is a nice plane. We were considering it as well. For ultimate
> performance of a flying wing you should have a look at the race guys,
> like:
> http://www.franz-josef-ney-online.de/Fotos/zezehn.JPG
> http://www.franz-josef-ney-online.de/Fotos/F5B-2011-Ney.jpg
>
> Cheers, Reto
>
> 2012/4/30 Chris <[hidden email]>:
> > Congratulations thats quite an achievement so please give us some more info!
> > I use the 9xtend with a joystick at 115200 and the up link now works fine.
> > I had similar problems but i solved them using the polled mode.
> > Was the plane always under power or you also used gliding?
> > What battery voltage and capacity did you used (3s, 4s etc) and what motor?
> > I am building a similar plane right now using the X8 as a test bed
> > Chris
> >
> >
> > _______________________________________________
> > Paparazzi-devel mailing list
> > [hidden email]
> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
> >
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Chris Efstathiou
In reply to this post by Reto Büttner
I get over 25km with 115200 (haven't tried further) and a 8dbi panel
antenna without any problems.
At 9600 i have gone as much as 40km out and the signal was rock solid
both ways so i bet it could
probably go further than that.
One thing to watch for is the airborne antenna, don't use the normal
900Mhz l/4 whip antenna,
use a dipole antenna (l/2) or a J pole.
If you use an antenna that can be rotated (swivel) keep the modem body
and the antenna
in a straight line, it makes a big difference.
I use this antenna
http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
You may also try a V dipole but not made from pcb (pcb antennas have a
lot of losses).
I haven't tried 9600bps and joystick control though only at 115200.
As i said i had up link problems at normal mode but when i switched to
the polling mode
all problems went away, instant response to GCS and joystick commands
with no visible latency.
Nice plane you got i am sure that it must have almost no drag as it
looks really slick.
Chris


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Re: Long Range Flying Wing

Reto Büttner
Hi Chris

We have problems over 25 km with 9600 baud. Something must be wrong in
our setup. We use a dipol antenna on the plane as well, very similar
to yours.

Thanks for the tip to keep the modem body and the antenna in a
straight line. In our current configuration we have a 90 degree bend.
We will check on mounting it in a straight line.

Cheers, Reto

2012/5/1 Chris <[hidden email]>:

> I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna
> without any problems.
> At 9600 i have gone as much as 40km out and the signal was rock solid both
> ways so i bet it could
> probably go further than that.
> One thing to watch for is the airborne antenna, don't use the normal 900Mhz
> l/4 whip antenna,
> use a dipole antenna (l/2) or a J pole.
> If you use an antenna that can be rotated (swivel) keep the modem body and
> the antenna
> in a straight line, it makes a big difference.
> I use this antenna
> http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
> You may also try a V dipole but not made from pcb (pcb antennas have a lot
> of losses).
> I haven't tried 9600bps and joystick control though only at 115200.
> As i said i had up link problems at normal mode but when i switched to the
> polling mode
> all problems went away, instant response to GCS and joystick commands with
> no visible latency.
> Nice plane you got i am sure that it must have almost no drag as it looks
> really slick.
>
> Chris
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Chris Efstathiou
In reply to this post by Reto Büttner
Btw can i get a plane like your's ready made or i have to construct it
my self?
Where can i buy one if possible?
Chris


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Re: Long Range Flying Wing

Reto Büttner
Our plane is custom design and home built. We didn't find anything on
the market in this class.

Regards, Reto

2012/5/1 Chris <[hidden email]>:

> Btw can i get a plane like your's ready made or i have to construct it my
> self?
> Where can i buy one if possible?
>
> Chris
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

agressiva
mais que arigó .... esqueci  link
http://www.youtube.com/watch?v=nKf566KVfMo

Nossa asa ja esta cadastrada no site do piloto automatico como airframe


> Date: Wed, 2 May 2012 00:12:41 +0200

> From: [hidden email]
> To: [hidden email]
> Subject: Re: [Paparazzi-devel] Long Range Flying Wing
>
> Our plane is custom design and home built. We didn't find anything on
> the market in this class.
>
> Regards, Reto
>
> 2012/5/1 Chris <[hidden email]>:
> > Btw can i get a plane like your's ready made or i have to construct it my
> > self?
> > Where can i buy one if possible?
> >
> > Chris
> >
> >
> > _______________________________________________
> > Paparazzi-devel mailing list
> > [hidden email]
> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

agressiva
OPsss sorry friends !
this mail is for another friend ... not ppz group;


From: [hidden email]
To: [hidden email]
Date: Wed, 2 May 2012 17:29:47 +0000
Subject: Re: [Paparazzi-devel] Long Range Flying Wing

mais que arigó .... esqueci  link
http://www.youtube.com/watch?v=nKf566KVfMo

Nossa asa ja esta cadastrada no site do piloto automatico como airframe


> Date: Wed, 2 May 2012 00:12:41 +0200

> From: [hidden email]
> To: [hidden email]
> Subject: Re: [Paparazzi-devel] Long Range Flying Wing
>
> Our plane is custom design and home built. We didn't find anything on
> the market in this class.
>
> Regards, Reto
>
> 2012/5/1 Chris <[hidden email]>:
> > Btw can i get a plane like your's ready made or i have to construct it my
> > self?
> > Where can i buy one if possible?
> >
> > Chris
> >
> >
> > _______________________________________________
> > Paparazzi-devel mailing list
> > [hidden email]
> > https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

_______________________________________________ Paparazzi-devel mailing list [hidden email] https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Stephen Dwyer
In reply to this post by Reto Büttner
Hello Reto,

We use 9XTend modems as well and used to have exactly the issues you
describe regarding the downlink working (mostly) fine but not being
able to change settings properly. I had discussed this with Chris
previously, and he recommended polling as he did here.

After playing with the various settings randomly, we found it
difficult to find a good setup. So, we looked into the issue further.
After closely reading the manual and studying the state flowcharts, we
hooked up a logic analyzer to the tx and rx lines on the ground and
airborne sides as well as to the rx led and tx power pins on the
modems.

We discovered that the default settings for the modems do not work at
all. While in operation it appears as though the settings don't
change. Looking at the logic output, one observes that more often than
not, the groundside modem receives a command packet at about the same
time the airborne side receives a telemetry packet. Each modem goes
into transmit mode and attempts to send the packet, resulting in a
collision. Under streaming or basic reliable mode (no
acknowledgements), both packets are sent but not received because each
modem is transmitting at the same time, and thus cannot receive. In
acknowledge mode, the default settings have the same retries with no
delay, so both sides continuously attempt to transmit but never
receive an acknowledgement. Each modem receiving a packet at the same
time seems to happen very often (almost always).

Instead, each modem must be configured a little bit differently. We
found the both acknowledged mode and polling acknowledged mode work
quite well. Polling mode essentially eliminates all packet collisions
but induces a bit more latency in one direction (from remote to base).
Normal acknowledged mode has some collisions, but these collisions
seem always to be resolved.

I have posted some sample configurations here:
http://paparazzi.enac.fr/wiki/Modems#Configuration

I am sure other configurations work, and we haven't flown with the
above configs, but it seems to work rather nicely in lab testing with
a TWOG + Aspirin. Thanks to Chris for pointing us in the polling
direction initially.

Hope that helps anyone having issues.

Thanks,
-Stephen Dwyer

On Tue, May 1, 2012 at 12:59 AM, Reto Büttner <[hidden email]> wrote:

> Hi Chris
>
> We have problems over 25 km with 9600 baud. Something must be wrong in
> our setup. We use a dipol antenna on the plane as well, very similar
> to yours.
>
> Thanks for the tip to keep the modem body and the antenna in a
> straight line. In our current configuration we have a 90 degree bend.
> We will check on mounting it in a straight line.
>
> Cheers, Reto
>
> 2012/5/1 Chris <[hidden email]>:
>> I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna
>> without any problems.
>> At 9600 i have gone as much as 40km out and the signal was rock solid both
>> ways so i bet it could
>> probably go further than that.
>> One thing to watch for is the airborne antenna, don't use the normal 900Mhz
>> l/4 whip antenna,
>> use a dipole antenna (l/2) or a J pole.
>> If you use an antenna that can be rotated (swivel) keep the modem body and
>> the antenna
>> in a straight line, it makes a big difference.
>> I use this antenna
>> http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
>> You may also try a V dipole but not made from pcb (pcb antennas have a lot
>> of losses).
>> I haven't tried 9600bps and joystick control though only at 115200.
>> As i said i had up link problems at normal mode but when i switched to the
>> polling mode
>> all problems went away, instant response to GCS and joystick commands with
>> no visible latency.
>> Nice plane you got i am sure that it must have almost no drag as it looks
>> really slick.
>>
>> Chris
>>
>>
>> _______________________________________________
>> Paparazzi-devel mailing list
>> [hidden email]
>> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>

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Re: Long Range Flying Wing

Cameron Lee-3
In reply to this post by Chris Efstathiou

Thanks for the advice Chris.

I am wondering though, why do you suggest using a 1/2 wavelength antenna in the plane instead of a 1/4? You say it as if its more important than on the ground. Or is the assumption that a 1/2 already being used on the ground. My current setup with the XTends is a 1/2 with a bend in the ground and a 1/4 in the air. This should give at least 5km right?

Cameron

On Apr 30, 2012 4:46 PM, "Chris" <[hidden email]> wrote:
I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna without any problems.
At 9600 i have gone as much as 40km out and the signal was rock solid both ways so i bet it could
probably go further than that.
One thing to watch for is the airborne antenna, don't use the normal 900Mhz l/4 whip antenna,
use a dipole antenna (l/2) or a J pole.
If you use an antenna that can be rotated (swivel) keep the modem body and the antenna
in a straight line, it makes a big difference.
I use this antenna http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
You may also try a V dipole but not made from pcb (pcb antennas have a lot of losses).
I haven't tried 9600bps and joystick control though only at 115200.
As i said i had up link problems at normal mode but when i switched to the polling mode
all problems went away, instant response to GCS and joystick commands with no visible latency.
Nice plane you got i am sure that it must have almost no drag as it looks really slick.
Chris


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Re: Long Range Flying Wing

Reto Büttner
In reply to this post by Stephen Dwyer
Hi Stephen

Thanks for the research, the info here and on the wiki. Looking at all the work needed, the guys from MaxStream resp. Digi probably should improve the "plug-and-play" capabilities of the 9XTend ...

Here are alternative instructions to configure the polling mode:

http://www.digi.com/support/kbase/kbaseresultdetl?id=2178

We intend our next tests with the new configurations by end of next week. I will let you know the results.

Cheers,
Reto

Am 10.05.2012 um 02:15 schrieb Stephen Dwyer <[hidden email]>:

Hello Reto,

We use 9XTend modems as well and used to have exactly the issues you
describe regarding the downlink working (mostly) fine but not being
able to change settings properly. I had discussed this with Chris
previously, and he recommended polling as he did here.

After playing with the various settings randomly, we found it
difficult to find a good setup. So, we looked into the issue further.
After closely reading the manual and studying the state flowcharts, we
hooked up a logic analyzer to the tx and rx lines on the ground and
airborne sides as well as to the rx led and tx power pins on the
modems.

We discovered that the default settings for the modems do not work at
all. While in operation it appears as though the settings don't
change. Looking at the logic output, one observes that more often than
not, the groundside modem receives a command packet at about the same
time the airborne side receives a telemetry packet. Each modem goes
into transmit mode and attempts to send the packet, resulting in a
collision. Under streaming or basic reliable mode (no
acknowledgements), both packets are sent but not received because each
modem is transmitting at the same time, and thus cannot receive. In
acknowledge mode, the default settings have the same retries with no
delay, so both sides continuously attempt to transmit but never
receive an acknowledgement. Each modem receiving a packet at the same
time seems to happen very often (almost always).

Instead, each modem must be configured a little bit differently. We
found the both acknowledged mode and polling acknowledged mode work
quite well. Polling mode essentially eliminates all packet collisions
but induces a bit more latency in one direction (from remote to base).
Normal acknowledged mode has some collisions, but these collisions
seem always to be resolved.

I have posted some sample configurations here:
http://paparazzi.enac.fr/wiki/Modems#Configuration

I am sure other configurations work, and we haven't flown with the
above configs, but it seems to work rather nicely in lab testing with
a TWOG + Aspirin. Thanks to Chris for pointing us in the polling
direction initially.

Hope that helps anyone having issues.

Thanks,
-Stephen Dwyer

On Tue, May 1, 2012 at 12:59 AM, Reto Büttner <[hidden email]> wrote:
Hi Chris

We have problems over 25 km with 9600 baud. Something must be wrong in
our setup. We use a dipol antenna on the plane as well, very similar
to yours.

Thanks for the tip to keep the modem body and the antenna in a
straight line. In our current configuration we have a 90 degree bend.
We will check on mounting it in a straight line.

Cheers, Reto

2012/5/1 Chris <[hidden email]>:
I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna
without any problems.
At 9600 i have gone as much as 40km out and the signal was rock solid both
ways so i bet it could
probably go further than that.
One thing to watch for is the airborne antenna, don't use the normal 900Mhz
l/4 whip antenna,
use a dipole antenna (l/2) or a J pole.
If you use an antenna that can be rotated (swivel) keep the modem body and
the antenna
in a straight line, it makes a big difference.
I use this antenna
http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
You may also try a V dipole but not made from pcb (pcb antennas have a lot
of losses).
I haven't tried 9600bps and joystick control though only at 115200.
As i said i had up link problems at normal mode but when i switched to the
polling mode
all problems went away, instant response to GCS and joystick commands with
no visible latency.
Nice plane you got i am sure that it must have almost no drag as it looks
really slick.

Chris


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Re: Long Range Flying Wing

Stephen Dwyer
Hello Reto,

Thanks for the link. I added it to the Modem page. Keep in mind that
config isn't really optimized for low latency comms on UAS, but it
does explain most of the important commands.

In addition, I think the default modem setup is fine for communication
between two radios working on the assumption that usually only one is
going to attempt to transmit at a time, rather unlike the paparazzi
datalink situation. But yes, a few more example situations and setups
wouldn't hurt in the docs...

Thanks,
-Stephen



On Thu, May 10, 2012 at 5:44 AM, Reto Büttner <[hidden email]> wrote:

> Hi Stephen
>
> Thanks for the research, the info here and on the wiki. Looking at all the
> work needed, the guys from MaxStream resp. Digi probably should improve the
> "plug-and-play" capabilities of the 9XTend ...
>
> Here are alternative instructions to configure the polling mode:
>
> http://www.digi.com/support/kbase/kbaseresultdetl?id=2178
>
> We intend our next tests with the new configurations by end of next week. I
> will let you know the results.
>
> Cheers,
> Reto
>
> Am 10.05.2012 um 02:15 schrieb Stephen Dwyer <[hidden email]>:
>
>
> Hello Reto,
>
>
> We use 9XTend modems as well and used to have exactly the issues you
>
> describe regarding the downlink working (mostly) fine but not being
>
> able to change settings properly. I had discussed this with Chris
>
> previously, and he recommended polling as he did here.
>
>
> After playing with the various settings randomly, we found it
>
> difficult to find a good setup. So, we looked into the issue further.
>
> After closely reading the manual and studying the state flowcharts, we
>
> hooked up a logic analyzer to the tx and rx lines on the ground and
>
> airborne sides as well as to the rx led and tx power pins on the
>
> modems.
>
>
> We discovered that the default settings for the modems do not work at
>
> all. While in operation it appears as though the settings don't
>
> change. Looking at the logic output, one observes that more often than
>
> not, the groundside modem receives a command packet at about the same
>
> time the airborne side receives a telemetry packet. Each modem goes
>
> into transmit mode and attempts to send the packet, resulting in a
>
> collision. Under streaming or basic reliable mode (no
>
> acknowledgements), both packets are sent but not received because each
>
> modem is transmitting at the same time, and thus cannot receive. In
>
> acknowledge mode, the default settings have the same retries with no
>
> delay, so both sides continuously attempt to transmit but never
>
> receive an acknowledgement. Each modem receiving a packet at the same
>
> time seems to happen very often (almost always).
>
>
> Instead, each modem must be configured a little bit differently. We
>
> found the both acknowledged mode and polling acknowledged mode work
>
> quite well. Polling mode essentially eliminates all packet collisions
>
> but induces a bit more latency in one direction (from remote to base).
>
> Normal acknowledged mode has some collisions, but these collisions
>
> seem always to be resolved.
>
>
> I have posted some sample configurations here:
>
> http://paparazzi.enac.fr/wiki/Modems#Configuration
>
>
> I am sure other configurations work, and we haven't flown with the
>
> above configs, but it seems to work rather nicely in lab testing with
>
> a TWOG + Aspirin. Thanks to Chris for pointing us in the polling
>
> direction initially.
>
>
> Hope that helps anyone having issues.
>
>
> Thanks,
>
> -Stephen Dwyer
>
>
> On Tue, May 1, 2012 at 12:59 AM, Reto Büttner <[hidden email]>
> wrote:
>
> Hi Chris
>
>
> We have problems over 25 km with 9600 baud. Something must be wrong in
>
> our setup. We use a dipol antenna on the plane as well, very similar
>
> to yours.
>
>
> Thanks for the tip to keep the modem body and the antenna in a
>
> straight line. In our current configuration we have a 90 degree bend.
>
> We will check on mounting it in a straight line.
>
>
> Cheers, Reto
>
>
> 2012/5/1 Chris <[hidden email]>:
>
> I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna
>
> without any problems.
>
> At 9600 i have gone as much as 40km out and the signal was rock solid both
>
> ways so i bet it could
>
> probably go further than that.
>
> One thing to watch for is the airborne antenna, don't use the normal 900Mhz
>
> l/4 whip antenna,
>
> use a dipole antenna (l/2) or a J pole.
>
> If you use an antenna that can be rotated (swivel) keep the modem body and
>
> the antenna
>
> in a straight line, it makes a big difference.
>
> I use this antenna
>
> http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
>
> You may also try a V dipole but not made from pcb (pcb antennas have a lot
>
> of losses).
>
> I haven't tried 9600bps and joystick control though only at 115200.
>
> As i said i had up link problems at normal mode but when i switched to the
>
> polling mode
>
> all problems went away, instant response to GCS and joystick commands with
>
> no visible latency.
>
> Nice plane you got i am sure that it must have almost no drag as it looks
>
> really slick.
>
>
> Chris
>
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
> _______________________________________________
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> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>

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Re: Long Range Flying Wing

Reto Büttner
In reply to this post by Chris Efstathiou
Hi Chris

Consider the Topsky Manta Ray:

http://www.topsoaring.com/index_pro_EPwing.htm

Cheers, Reto

2012/5/1 Chris <[hidden email]>:

> Btw can i get a plane like your's ready made or i have to construct it my
> self?
> Where can i buy one if possible?
>
> Chris
>
>
> _______________________________________________
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> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Reto Büttner
In reply to this post by Reto Büttner
Hi Stephen

We configured our 9XTends according to your recommendation
(Acknowledged Polling Mode):

http://paparazzi.enac.fr/wiki/Modems#Configuration

As we are sending lots of telemetry and not using datalink joystick
control we chose the air module as the base. It gets pretty warm in
operation. In the workshop everything works fine.

On the field we experience a very asymmetrical link: The telemetry
data from the aircraft gets well to the ground station, also at range.
But the commands from the ground station only get to the aircraft at
very close range. At range we don't get any commands from the ground
station to the aircraft anymore.

Can you explain this behaviour? How do you achieve a symmetrical data link?

We still have a 90 degree bend between the modem body and the antenna
on the airplane. On the ground station we have them in a straight
line. Could this explain the asymmetrical link?

Regards, Reto

2012/5/10 Reto Büttner <[hidden email]>:

> Hi Stephen
>
> Thanks for the research, the info here and on the wiki. Looking at all the
> work needed, the guys from MaxStream resp. Digi probably should improve the
> "plug-and-play" capabilities of the 9XTend ...
>
> Here are alternative instructions to configure the polling mode:
>
> http://www.digi.com/support/kbase/kbaseresultdetl?id=2178
>
> We intend our next tests with the new configurations by end of next week. I
> will let you know the results.
>
> Cheers,
> Reto
>
> Am 10.05.2012 um 02:15 schrieb Stephen Dwyer <[hidden email]>:
>
>
> Hello Reto,
>
>
> We use 9XTend modems as well and used to have exactly the issues you
>
> describe regarding the downlink working (mostly) fine but not being
>
> able to change settings properly. I had discussed this with Chris
>
> previously, and he recommended polling as he did here.
>
>
> After playing with the various settings randomly, we found it
>
> difficult to find a good setup. So, we looked into the issue further.
>
> After closely reading the manual and studying the state flowcharts, we
>
> hooked up a logic analyzer to the tx and rx lines on the ground and
>
> airborne sides as well as to the rx led and tx power pins on the
>
> modems.
>
>
> We discovered that the default settings for the modems do not work at
>
> all. While in operation it appears as though the settings don't
>
> change. Looking at the logic output, one observes that more often than
>
> not, the groundside modem receives a command packet at about the same
>
> time the airborne side receives a telemetry packet. Each modem goes
>
> into transmit mode and attempts to send the packet, resulting in a
>
> collision. Under streaming or basic reliable mode (no
>
> acknowledgements), both packets are sent but not received because each
>
> modem is transmitting at the same time, and thus cannot receive. In
>
> acknowledge mode, the default settings have the same retries with no
>
> delay, so both sides continuously attempt to transmit but never
>
> receive an acknowledgement. Each modem receiving a packet at the same
>
> time seems to happen very often (almost always).
>
>
> Instead, each modem must be configured a little bit differently. We
>
> found the both acknowledged mode and polling acknowledged mode work
>
> quite well. Polling mode essentially eliminates all packet collisions
>
> but induces a bit more latency in one direction (from remote to base).
>
> Normal acknowledged mode has some collisions, but these collisions
>
> seem always to be resolved.
>
>
> I have posted some sample configurations here:
>
> http://paparazzi.enac.fr/wiki/Modems#Configuration
>
>
> I am sure other configurations work, and we haven't flown with the
>
> above configs, but it seems to work rather nicely in lab testing with
>
> a TWOG + Aspirin. Thanks to Chris for pointing us in the polling
>
> direction initially.
>
>
> Hope that helps anyone having issues.
>
>
> Thanks,
>
> -Stephen Dwyer
>
>
> On Tue, May 1, 2012 at 12:59 AM, Reto Büttner <[hidden email]>
> wrote:
>
> Hi Chris
>
>
> We have problems over 25 km with 9600 baud. Something must be wrong in
>
> our setup. We use a dipol antenna on the plane as well, very similar
>
> to yours.
>
>
> Thanks for the tip to keep the modem body and the antenna in a
>
> straight line. In our current configuration we have a 90 degree bend.
>
> We will check on mounting it in a straight line.
>
>
> Cheers, Reto
>
>
> 2012/5/1 Chris <[hidden email]>:
>
> I get over 25km with 115200 (haven't tried further) and a 8dbi panel antenna
>
> without any problems.
>
> At 9600 i have gone as much as 40km out and the signal was rock solid both
>
> ways so i bet it could
>
> probably go further than that.
>
> One thing to watch for is the airborne antenna, don't use the normal 900Mhz
>
> l/4 whip antenna,
>
> use a dipole antenna (l/2) or a J pole.
>
> If you use an antenna that can be rotated (swivel) keep the modem body and
>
> the antenna
>
> in a straight line, it makes a big difference.
>
> I use this antenna
>
> http://www.dpcav.com/xcart/900MHz-Antenna-Compact-Dipole.html
>
> You may also try a V dipole but not made from pcb (pcb antennas have a lot
>
> of losses).
>
> I haven't tried 9600bps and joystick control though only at 115200.
>
> As i said i had up link problems at normal mode but when i switched to the
>
> polling mode
>
> all problems went away, instant response to GCS and joystick commands with
>
> no visible latency.
>
> Nice plane you got i am sure that it must have almost no drag as it looks
>
> really slick.
>
>
> Chris
>
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
>
> _______________________________________________
>
> Paparazzi-devel mailing list
>
> [hidden email]
>
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Chris Efstathiou
In reply to this post by Reto Büttner
Well i have flown to a point where the ground station with its 8db patch
could not receive well
the planes data but i was still able to give a command to the plane and
return it home which indicates
good airborne reception.
I use as stated the polling mode with no confirmation and retries are
set to 0.
I have set the addresses somewhere in the top range, FFF0-FFF1 i think
and changed the channel
to 9 (different hopping frequencies).
One day i had a problem communicating with the plane (the downlink was
fine)
and it proved to be the video tx.
Since then i have fitted filters to the video tx (high pass) and the
modem (low pass)
and all problems were solved.
The antenna and the modem have to be in a straight line otherwise SWR
will rise,
RF will flow through the wires all over the airplane causing havoc and
the antenna
radiation pattern will be greatly distorted.
The same goes for the video tx.
Chris

Hi Stephen

We configured our 9XTends according to your recommendation
(Acknowledged Polling Mode):

http://paparazzi.enac.fr/wiki/Modems#Configuration

As we are sending lots of telemetry and not using datalink joystick
control we chose the air module as the base. It gets pretty warm in
operation. In the workshop everything works fine.

On the field we experience a very asymmetrical link: The telemetry
data from the aircraft gets well to the ground station, also at range.
But the commands from the ground station only get to the aircraft at
very close range. At range we don't get any commands from the ground
station to the aircraft anymore.

Can you explain this behaviour? How do you achieve a symmetrical data link?

We still have a 90 degree bend between the modem body and the antenna
on the airplane. On the ground station we have them in a straight
line. Could this explain the asymmetrical link?

Regards, Reto

2



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Re: Long Range Flying Wing

Stephen Dwyer
Hello,

Regarding range issues:

First thing, is the power setting appropriate on both sides?

As Chris mentioned, definitely possibilities of interference from
other equipment. This can be very hard to debug. As an example, in the
past we had horrible problems with GPS reception. After days of
changing things around, we used a spectrum analyzer to debug, which
really helped solve the problem. I realize it can be difficult to get
access to a spectrum analyzer (turned out to be the 500MHz SBC spewing
junk RFI at 1.5GHz ... a nice harmonic, some careful shielding solved
the problem).

We had serious asymmetrical link issues for a while as well. After
some debugging, we discovered that the connector on one of the
antennas was in poor condition. Switching to a new antenna solved all
of our problems. However, this asymmetry also showed significantly
decreased range, even in the better telemetry direction. Again, Chris
mentioned this: antenna selection, antenna/cable setup and orientation
are rather important.

Our modems also run warm, but I think this is to be expected with the
high power. We make sure to allow some air flow around the modems
(i.e. we don't wrap them in foam).

A while ago I wrote a small module to measure the RSSI on the airborne
side to help debug range problems. It was quite a while back and I am
not sure if it is still alive (a quick compile on master failed). I
will try to fix it in the next couple days if I get a chance, and do
some proper documentation on the wiki for it. Unfortunately, it is
currently for LPC21xx only (we use it on a TWOG). Check
conf/modules/xtend_rssi.xml for more info.

Hope that helps.

Thanks,
-Stephen Dwyer




On Fri, Jul 6, 2012 at 11:09 AM, Chris <[hidden email]> wrote:

> Well i have flown to a point where the ground station with its 8db patch
> could not receive well
> the planes data but i was still able to give a command to the plane and
> return it home which indicates
> good airborne reception.
> I use as stated the polling mode with no confirmation and retries are set to
> 0.
> I have set the addresses somewhere in the top range, FFF0-FFF1 i think and
> changed the channel
> to 9 (different hopping frequencies).
> One day i had a problem communicating with the plane (the downlink was fine)
> and it proved to be the video tx.
> Since then i have fitted filters to the video tx (high pass) and the modem
> (low pass)
> and all problems were solved.
> The antenna and the modem have to be in a straight line otherwise SWR will
> rise,
> RF will flow through the wires all over the airplane causing havoc and the
> antenna
> radiation pattern will be greatly distorted.
> The same goes for the video tx.
> Chris
>
>
> Hi Stephen
>
> We configured our 9XTends according to your recommendation
> (Acknowledged Polling Mode):
>
> http://paparazzi.enac.fr/wiki/Modems#Configuration
>
> As we are sending lots of telemetry and not using datalink joystick
> control we chose the air module as the base. It gets pretty warm in
> operation. In the workshop everything works fine.
>
> On the field we experience a very asymmetrical link: The telemetry
> data from the aircraft gets well to the ground station, also at range.
> But the commands from the ground station only get to the aircraft at
> very close range. At range we don't get any commands from the ground
> station to the aircraft anymore.
>
> Can you explain this behaviour? How do you achieve a symmetrical data link?
>
> We still have a 90 degree bend between the modem body and the antenna
> on the airplane. On the ground station we have them in a straight
> line. Could this explain the asymmetrical link?
>
> Regards, Reto
>
> 2
>
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>

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Re: Long Range Flying Wing

agressiva
In reply to this post by Chris Efstathiou
Well, i am using xbee 900mhz and configured the ppz to work on 9600kbps.
with this config i receive all telemetry data but is very dificult to send command to airplane.
Some time i need to clic more than 10 time airplane accept the command.

even change waypoint position is very difficult.


> Date: Fri, 6 Jul 2012 20:09:52 +0300

> From: [hidden email]
> To: [hidden email]
> Subject: Re: [Paparazzi-devel] Long Range Flying Wing
>
> Well i have flown to a point where the ground station with its 8db patch
> could not receive well
> the planes data but i was still able to give a command to the plane and
> return it home which indicates
> good airborne reception.
> I use as stated the polling mode with no confirmation and retries are
> set to 0.
> I have set the addresses somewhere in the top range, FFF0-FFF1 i think
> and changed the channel
> to 9 (different hopping frequencies).
> One day i had a problem communicating with the plane (the downlink was
> fine)
> and it proved to be the video tx.
> Since then i have fitted filters to the video tx (high pass) and the
> modem (low pass)
> and all problems were solved.
> The antenna and the modem have to be in a straight line otherwise SWR
> will rise,
> RF will flow through the wires all over the airplane causing havoc and
> the antenna
> radiation pattern will be greatly distorted.
> The same goes for the video tx.
> Chris
>
> Hi Stephen
>
> We configured our 9XTends according to your recommendation
> (Acknowledged Polling Mode):
>
> http://paparazzi.enac.fr/wiki/Modems#Configuration
>
> As we are sending lots of telemetry and not using datalink joystick
> control we chose the air module as the base. It gets pretty warm in
> operation. In the workshop everything works fine.
>
> On the field we experience a very asymmetrical link: The telemetry
> data from the aircraft gets well to the ground station, also at range.
> But the commands from the ground station only get to the aircraft at
> very close range. At range we don't get any commands from the ground
> station to the aircraft anymore.
>
> Can you explain this behaviour? How do you achieve a symmetrical data link?
>
> We still have a 90 degree bend between the modem body and the antenna
> on the airplane. On the ground station we have them in a straight
> line. Could this explain the asymmetrical link?
>
> Regards, Reto
>
> 2
>
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel

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Re: Long Range Flying Wing

Stephen Dwyer
Hey Eduardo,

This is very similar to what we used to experience before a correct
configuration. It occurred on the 9Xtends because the packets from the
ground collided with the packets from the air almost every time.
Incorrect delay, retry and other settings were not resolving these
collisions correctly. To determine exactly what happened, a logic
analyzer was a huge help, if you have access to one. For further
information, see:
http://lists.gnu.org/archive/html/paparazzi-devel/2012-05/msg00081.html

It definitely helps to carefully read through the manual and undertand
about each setting.

Hope that helps.

Thanks,
-Stephen Dwyer

On Fri, Jul 6, 2012 at 3:15 PM, Eduardo lavratti <[hidden email]> wrote:

> Well, i am using xbee 900mhz and configured the ppz to work on 9600kbps.
> with this config i receive all telemetry data but is very dificult to send
> command to airplane.
> Some time i need to clic more than 10 time airplane accept the command.
>
> even change waypoint position is very difficult.
>
>
>> Date: Fri, 6 Jul 2012 20:09:52 +0300
>> From: [hidden email]
>
>> To: [hidden email]
>> Subject: Re: [Paparazzi-devel] Long Range Flying Wing
>>
>> Well i have flown to a point where the ground station with its 8db patch
>> could not receive well
>> the planes data but i was still able to give a command to the plane and
>> return it home which indicates
>> good airborne reception.
>> I use as stated the polling mode with no confirmation and retries are
>> set to 0.
>> I have set the addresses somewhere in the top range, FFF0-FFF1 i think
>> and changed the channel
>> to 9 (different hopping frequencies).
>> One day i had a problem communicating with the plane (the downlink was
>> fine)
>> and it proved to be the video tx.
>> Since then i have fitted filters to the video tx (high pass) and the
>> modem (low pass)
>> and all problems were solved.
>> The antenna and the modem have to be in a straight line otherwise SWR
>> will rise,
>> RF will flow through the wires all over the airplane causing havoc and
>> the antenna
>> radiation pattern will be greatly distorted.
>> The same goes for the video tx.
>> Chris
>>
>> Hi Stephen
>>
>> We configured our 9XTends according to your recommendation
>> (Acknowledged Polling Mode):
>>
>> http://paparazzi.enac.fr/wiki/Modems#Configuration
>>
>> As we are sending lots of telemetry and not using datalink joystick
>> control we chose the air module as the base. It gets pretty warm in
>> operation. In the workshop everything works fine.
>>
>> On the field we experience a very asymmetrical link: The telemetry
>> data from the aircraft gets well to the ground station, also at range.
>> But the commands from the ground station only get to the aircraft at
>> very close range. At range we don't get any commands from the ground
>> station to the aircraft anymore.
>>
>> Can you explain this behaviour? How do you achieve a symmetrical data
>> link?
>>
>> We still have a 90 degree bend between the modem body and the antenna
>> on the airplane. On the ground station we have them in a straight
>> line. Could this explain the asymmetrical link?
>>
>> Regards, Reto
>>
>> 2
>>
>>
>>
>> _______________________________________________
>> Paparazzi-devel mailing list
>> [hidden email]
>> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
> _______________________________________________
> Paparazzi-devel mailing list
> [hidden email]
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>

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