Is there a device that will bring a plane back to launch point?

[randall1959]

I'm looking for a friend that's doing a science project. I was under the impression that there is a device that you either program gps coordinants into or it remembers on it's own once it's powered up.
I thought there was something about if you lost the signal or if you centered the sticks for a time it would begin to return back to the point of launch. Any suggestions who makes such a thing or was I dreaming??? :rolleyes:

[kd7ost]

Hey Randall,

There are a variety of items out there to do just what you ask. I have such items in both my planes. One an electric plane, my Dragonfly, and one in my Gas powered Pegasus1.

Both devices I use come from UNAV. http://www.u-nav.com/ One is called the PDC-10 and is no longer being made. It connects up to a handheld GPS unit and you would put in your location as a waypoint. Then you tell your GPS to "goto" that location. You connected it in line with your rudder. It also connects up to a spare channel used as an enable line. While disabled it just passes your rudder signals right through. When enabled it would take the GPS information and take over your rudder and steer the plane back to you. Naturally your plane has to be dynamically stable, (polyhedral or a fair amount of dihedral) or like I do just put a co-pilot on roll and your plane will make big flat turns coming back to you. I like that set up for AP batter anyway. It keeps the camera from swinging all over as your plane yaws, pitches and rolls. I'm giving away a never been used PDC-10 in a few weeks as a prize in this contest.

http://www.rcgroups.com/forums/showthread.php?t=608887

UNAV now sells the Pico Pilot. It costs a bit more but is a solid unit. Small, lightweight and has its own built in GPS unit. They have a version called the RTL. That’s just a return to launch unit. You power up the GPS, it gets lock and when the LED goes out it's ready to go. It just loaded the coordinates of your location itself. No user interface required.

There is also a device quire similar to the PDC-10 sold by MX called the RCAP. In this case the acronym means Remote Controlled Auto Pilot. I have used one of those and it works great too. There is a smaller version in the works and I haven't kept up with it. Perhaps MX will jump in and add more information.

All of these units work in quite similar ways. I use a PCM radio and have the failsafe programmed to keep things enabled just in case I have interference or what have you. They will prevent a fly off.

Dan

[lvspark]

UNAV RTL i think
http://www.u-nav.com/picopilot/picopilotrtl.html

Edit: typing at the same time as Dan :p

[icebear]

Randall,

I think Dan's reply covers all of it, but I just wanted to add a comment on the Picopilot -RTL.
That verison is as Dan describes a 'return-to-launch' unit only. You can get the excact same functionality in the Picopilot -NAV unit, but here you can also enter your own waypoints to perform a programmed route.
All Picopilots include roll stabilization which means that you don't need to have an external device like the CO-pilot.

And the RCAP can be found here; http://scalerobotics.com/store/catalog/
(I am not sure MX sells them).


/Icebear

[kd7ost]

Good points Icebear,

Dan

[macboffin]

Along with some sort of G.P.S. enabled "steer for home", probably a good idea to also fit a "height hold" device, ensures plane doesnt slowly descend into terrain, or arrive back overhead too high to see or hear.U-NAV do one.
Mac.

[_helitron_]

Hi together,

I just build my new FPV-ship on base of the new big EPP E-glider from Multiplex
(see attached photos) included a RTL-function. I decided to use
the following stuff for that functionality:

ZLog Mod3 and WPS from MX (http://www.hexpertsystems.com/),
AltHold, RCAP3 and GPS-Rx from eladiomf
(http://alai.h3m.com/~s0350672/catalogo/index.php?cPath=43&sort=2a&language=en)
and a FS8 Co-Pilot from FMA direct (http://www.fmadirect.com/).

For sure it's a little bit of electronic skill necessary to glue this parts
to a whole system but it's not that difficult in my opinion.

Additional here threads for the parts mentioned above:

http://www.rcgroups.com/forums/showthread.php?t=633795
http://www.rcgroups.com/forums/showthread.php?t=652952
http://www.rcgroups.com/forums/showthread.php?t=515929

Greets, Erwin

[phubner]

Erwin,

Can't wait to see come pix / vids of your flight or from you FPV. I was _this_close_ to buying a cularis, but though - "baby steps, baby steps" and got an easy glider as my second plane.

Paul

[_helitron_]

Hi Paul,

first pics in the air I hope this week, vid a bit later :) ! Must install FPV stuff first ;) .

In the moment I'm cutting out decals ... :D .

Greets, Erwin

[_helitron_]

Hi,

as promised here some pix from the maiden of my new Cularis FPV-glider:

http://www.rcgroups.com/forums/showthread.php?t=616736&page=10

Ah yes, a new electronic gadget I've got in the meantime, an OSD from FredericG :D , will be then also a part of the FPV stuff !

Best wishes,

Erwin

[trackhead]

So would a U-Nav RTL function through the rudder on a plane like the Telemaster?

I have a TM 6' with the FMA copilot on ailerons/elevator now. So I'm assuming the RTL would control rudder for it's directional control? Are the two compatible (Copilot/Unav).

This type of device would be very helpful form me this winter, with long establishing video footage in the mountains.

[dalbert02]

An alternative to what has been listed so far is the AP-4 sold by a university student from time to time on eBay for about $200

http://plaza.ufl.edu/nuclear/ap4instr.html

-dave

[ios]

randall1959,

Another device which can do what you've described is the BTA AS-07G Auto Pilot with Plane Retriever - http://www.maxxprod.com/mpi/mpi-16.html

This device stabilizes an aircraft in the roll and pitch axis, maintains level flight when the control stick is in the neutral position, and allows airplane to turn without losing altitude.

With a PCM system, when Tx signal is lost, an autopilot will engage automatically, and return the model to the take off site and fly the airplane in a large circle.

I would ideally describe this as a semi-autonomous system as the idea is that you fly your plane around manually with some flight control augmentation, in the pitch and roll axis , and the only autonomous function is to return the plane back to were you started from when rx signal is lost(inadvertently or otherwise)

The advantage of this device is that your madel does not have to be dynamically stable (i believe), however it is not as compact, lightweight, or cheap as some of the other devices mentioned previously in this thread.

I havn't used UNav's autopilot, so I can't comment on that. I've used RCAP3 & AltHold successfully, and I highly recommend those devices for a stable airplane. I recently got the BTA AS-07 (without the autopilot module), and I'm intending to test this with RCAP3.

For those interested, I'm hoping to connect the RCAP3 rudder output to the BTA's Aileron Input. As the BTA is advertised not to allow your plane to roll inverted, & not to lose (significant) altitude during turns, I'm hopeing to demonstrate autonomous gps guided flight using aileron (RCAP3-->BTA), elevator (BTA), and throttle (RCAP3) controls.

Nik

[icebear]

So would a U-Nav RTL function through the rudder on a plane like the Telemaster?

I have a TM 6' with the FMA copilot on ailerons/elevator now. So I'm assuming the RTL would control rudder for it's directional control? Are the two compatible (Copilot/Unav).

Trackhead - you could use the PicopilotRTL like that, the RTL is basically the Picopilot NAV without route function (it just returns home). The Picopilot does however include a wingleveller so you could set failsafe to disable the copilot and let the Picopilot do both winglevelling and navigation. Or you could do as you described - I have tried it and it works even if UNav does not recommend that you have two units trying to control winglevelling at the same time.

I have tested the Picopilot with Co-pilot and they work very well together. You need small servo boosters to increase logiv to 5v if you have the FS-8 rx however (from Cermark for instance).

/Icebear

[trackhead]

Icebear,

Thanks for the reply. Very helpful.

I will likely set one up in a few months.