BTA AS-07 Auto Pilot

[rixkix]

Does anyone have any experience with this autopilot? With stabilization and a GPS port it looks like a good deal for $249, but I can't find out any other info on it.
http://www.maxxprod.com/mpi/mpi-16.html

[kd7ost]

I have one and have flown with it. It works well. The GPS port is not yet employed though. You may want to get a message to Maxxproducts asking them when they'll have that feature ready to go.

Dan

[Lost In OC]

That looks like a great deal....IF....the gps function actually works, and to what extent.

[kd7ost]

I talked to them about a year ago about it. They told me at that time the GPS unit wasn't built yet. I asked them if it was going to be made so you could follow a route. They said "no", that it was only going to be built so that it could fly back to the point where it first got GPS lock from. (presumably where you fly from) Just to prevent flyoffs. They said they wanted to stay under the radar of homeland security and wanted to be able to sell to AMA sanctioned clubs. I think AMA rules got stricter than they had hoped for. Anyhow, I haven't checked back with them lately. The BTA 07 sits in it's box on the shelf. I use a co-pilot and a PDC-10 with a hand held GPS, (geko 201) to do the job. I'll have some new PDC-10's available in about two weeks if anyone wants to PM me. I was going to announce it when I got the programmed PIC chips in but that should be pretty quick now. I'll only have about 10 of them available. They are no longer being made. U-nav is selling higher end parts now and is letting the Hobby line drop. I'm not with U-nav. Just wanted to get a few PDC-10's for myself so worked out a deal.

Dan

[nerys]

Why exactly would this be of any concern to homeland security ? sure once you go above 55 pounds your regulated and they can get involved anyway they want but at our masses its unregulated?

Is there a SIMPLY (ie affordable) solution for rudder only GPS control above 60,000 feet. I just want it to return the plane to me. I want to put a very large (but very light few pounds tops) airplane to 100k on a weather balloon and drop it and have it fly back to me. Once in range I can take over and land it. I want to send up a high def camcorder and get some killer cool video!! but I can not afford to loose my $600 camera :-)

This would also be great for FPP Flights if I go out of video range I could just turn off the TX and it would fly back to me :-)

Suggestions?
Chris Taylor
http://www.nerys.com/

[workshop]

Nerys,

You wrote "but I can not afford to loose my $600 camera :-)".

I believe that your risk aversion is too high. Loosing a $600 camera should be just a "piff" of a concern based on the time/money investment you are planning.

Jeff

[kd7ost]

Why exactly would this be of any concern to homeland security ? sure once you go above 55 pounds your regulated and they can get involved anyway they want but at our masses its unregulated?

Is there a SIMPLY (ie affordable) solution for rudder only GPS control above 60,000 feet. I just want it to return the plane to me. I want to put a very large (but very light few pounds tops) airplane to 100k on a weather balloon and drop it and have it fly back to me. Once in range I can take over and land it. I want to send up a high def camcorder and get some killer cool video!! but I can not afford to loose my $600 camera :-)

This would also be great for FPP Flights if I go out of video range I could just turn off the TX and it would fly back to me :-)

Suggestions?
Chris Taylor
http://www.nerys.com/


There is such a device. Off the shelf from UNAV and is called the Pico Pilot Nav A. Even though it has 31 user programmable waypoints, when you turn it on and let it get GPS lock it loads your location as waypoint 32. That one isn't user accesssible. Leave the other slots blank and it will skip those blank slots. Once under flight it will guide the plane back to that waypoint.

I agree with workshop on camera cost. The 600.00 dollar camera might be the single high dollar item but it will cost close to double that to put the rest of the ambitious project together. That's if you don't have to buy a laptop for tracking. You do intend to track it I presume? You can work through your local HAM radio club to run APRS like we do. A single balloon will cost you close to 100 dollars and you have to abide by FAR-101 to be legit. A few lower altitude test flights will be recommended. Helium will cost about 75.00 to 90.00 for a single K tank. It will take more than that to get your glider to over 100K'. It will also take a big balloon and a ground crew plus you'll have to put together a filling mechanism. The camera becomes a drop in the bucket. It can be done but you'll have to build up to it and integrate your system if you want your equipment back. You'll need an on board microcontroller, a 2 meter radio or packet transmitter, something that allows you to switch between autonomous and RC control etc. It's -60F to -90F up there. Correct battery technology is critical if you want it to work at those temperatures. It goes on and on. Make a test capsule first with a parachute just to see what it takes. That would be helpful to your process.

Dan

http://www.eoss.org/pubs/far_annotated.htm
http://www.u-nav.com/
http://www.tvnsp.org/

[Connexxion]

UNAV's picopilot doesn't work above 15.000 feet (MSL).I believe most autopilot's don't work above that altitude.

And if returning the plane is the only thing you want,you could get yourself the RTL (Return To Launch) picopilot.

http://www.u-nav.com/picopilot/picopilotrtl.html

[kd7ost]

I'm not sure about that actually.

The electronics themselves don't have any limits that I'm aware of save for temperature and voltage specs. Unless UNAV built in code that disables the unit if GPS altitude reads higher than that. I guess that would take an email but you could be on to something there. I'm thinking the upper limit may have more to do with the function of the altitude lock unit and it's BP device and reference voltages. Since one wouldn't be needed in this application, that part at least would be a non issue.

Usually limits in these types of applications involve the GPS unit itself. I know the one he supplies will work above 60,000 feet msl.

Whole heartedly agree on the RTL unit.

Dan

http://showcase.netins.net/web/wallio/GPSrcvrsvs60kft.htm

[ThaiskyDigital]

Does anyone have any experience with this autopilot? With stabilization and a GPS port it looks like a good deal for $249, but I can't find out any other info on it.
http://www.maxxprod.com/mpi/mpi-16.html


Yes I have one but still not yet test it.

[hihptsi]

......

[rcdoma]

Looks like Steve_molmer @RCU has modified BTA 07 Auto Pilot with Plane Retriever to follow waypoints. I am planning to get their basic AP for use with RCAP3.

See post #151
http://www.rcuniverse.com/forum/m_4552453/mpage_8/key_/tm.htm

[Wmacky]

How can this work with just one Gyro? Drift?

[dmgoedde]

Hello, I've developed an autopilot unit that isn't on the market yet, but here are the specs of my current (actually existing and usable) rev0 unit: up to 100k waypoints stored on micro SD memory card, WP position resolution to 0.00001 degree (about 3.8 feet) and up to no practical limit on Earth (sequential WPs can be up to 1.5 million miles apart), option of last WP to be the center of a holding pattern (octagon of points with specified radius), total system mass including GPS unit (the 32 channel 5Hz ETek EB-85A) is 1.6 ounces, PID control of rudder for steering and throttle for altitude control, elevator stays locked in last trim position when ground pilot engages unit from "manual" to "autonomous". Also, the altitude at each WP is individually set - so you could send a plane up and over a hill or mountain for example. Center of rudder and throttle position also are set from last value from pilot on the ground when unit is switched over to autonomous. The WPs on SD card are a simple text file "waypoint.txt" and employ XOR checksum for robustness. I currently generate WP files by using Google Earth to create a path, then export the .kml file, and run that file through a program to clean it up, though I'm not sure if I can market a system that depends on Google Earth as they specify in license agreement that it is to be used for non-commercial purposes.

Upon power up and initial GPS lock the unit sets a default holding pattern 300' over the launch site just in case the user-defined WP list doesn't specify a holding pattern location, or there is error with checksum when reading the WPs from SD card. Also includes a very sensitive barometer for altitude control (besides cross-check reference against GPS altitude values) - the SCP-1000 barometer with 9cm resolution, although my current software doesn't use the barometer, the marketed version will use barometer data to control elevator. Size is 3"x1.1"x0.5" - however I made no attempt to miniturize this Rev0 sytem as it uses rather large DIP components. when I get this to market it will use only SMD components and it will be about 1"x1"x0.25" and weight 0.8oz including GPS and antenna. Unit has a bank of female 0.1" spaced pins on one side and male pins on the other so it simply plugs directly between R/C Rx and the servos. Power is drawn from ground and Vcc pins of Rx. Current consumption is less than 50ma. Oh another thing, this rev0 software "trains" the autopilot by manual flight for about 1 minute, after which it does a data fitting routine and stores control constants to a .ini file on the SD card. After this training and upon subsequent power-ups the autopilot loads these control constants. Items taught by manula flight include servo direction, approximate trim centers, and response slopes; thus eliminating tedius gain tuning. To get this to market I have to pass some legal hurdles, as I fear this autopilot might be "too" capable (not that the non-hobby "professional" autopilots aren't). I've often wondered why hobby-oriented autopilots only store up to 32 or so WPs and have such basic controls. If I can't sell finished units for legal or liability reasons, I will sell kits at a more modest cost, though I anticipate selling finished complete units for considerably less than the 'other guys' - around $400 for the rudder/elevator/throttle unit for motor gliders, and $700 for an upcoming Kalman version with integrated IMU for no-dihedral aileron steered planes.

Interested? Feedback? Questions?

[zik]

Sounds like a great product dmgoedde. I'll watch your progress with keen interest!

[S_Dave]

Hello Dmgoedde,

Your information on the autopilot you are developing was very interesting. How is it progressing? Will you be offering these for sale in the future?
Thanks, and have a great weekend!

Dave
Atlanta, GA

[kd7ost]

He has a thread on it right here. It has been an active project and many are watching with keen interest.

http://www.rcgroups.com/forums/showthread.php?t=734456

Dan

[N2EC]

Anybody used it on a Delta/Flying WIng. Would like to know what the Test Results would be. For standard config, on pressing the Test Button the left aileron should go up and the elevator should also go up.

Not getting any responses from the manufacturer or Maxx.

[S_Dave]

Dan,

Thanks for the link on dmgoedde's very interesting project. I'm going to take time and absorb all of those posts and replies and get myself up to date on it.
AFTER I send out the R/C club newsletter....

Hope you enjoy a fine weekend. It's blue skies and low 60s F here in Atlanta. The flying field is calling.

73,

Dave
W4QDV

[magnetman]

Very interested- would be ideal for my FPV platform, I'm in UK

Regards

Richard

Interested? Feedback? Questions? Very interested- would be ideal for my FPV platform, I'm in UK

Regards

Richard

[dmgoedde]

Very interested- would be ideal for my FPV platform, I'm in UK

Regards

Richard
Richard,

FPV and aerial photography are ideal uses for it. We are definatley off topic on this thread though. Why not shoot me any questions you might have via PM?