UAVs Conquer The Skies

Fire Scout Scores First-Ever Drug Bust with McInerney

Check out Nima's two profiles, http://diydrones.com/profile/NimaKayvan and http://diydrones.com/profile/NimaK, as well as the Project Andromeda website: http://www.projectandromeda.com.au/

Also I forgot to mention last month was our first month to surpass 100GB of downloads. Crazy!

Today I flew my ParkZone Stryker with an AttoPilot IMU for the first time. The wind was 20mph and the loiter circle was 100m. I did not have a WP file set for today as I was checking my stabalization tuning. Some very minor changes needed but it really turned out extreemly well. I will fly some WP files tomorrow.

The following plots are:

Roll vs Roll target

Pitch vs Pitch target

Airspeed vs Airspeed target

Wind and Airspeed vs Heading

These birds fly rather well.

Chris

You can find product details at: http://www.01mech.com/supermodified

I copy the following from the site:

Google has recently scanned and posted all of Popular Science's back issues (and they go WAY back), and there are some gems in there from the early days of autopilots. One of them is this, which describes an autopilot the legendary Maynard Hill (yes, the guy who flew a hobby UAV across the Atlantic in 2003) built that uses minute electrostatic differences with altitude to create an analog autopilot.

Here are some other pictures from the article, but you should really read the whole thing. Anyone know what went wrong with this approach and why he abandoned it?

While we work on ArduPilot's big brother (Mega), we wanted it to have a little brother, too: a cheap and easy entry-level autopilot.

The best way to do that is with a tried-and-true design, a turn-rate-limiter. The way these work is that they have a yaw gyro and a GPS. The yaw gyro stabilizes the plane, based on the correlation between bank and yaw (it works best with relative stable aircraft, ideally those that are flown with the rudder rather than ailerons, such as the EasyStar or many high-wing trainers). Meanwhile the GPS corrects for yaw gyro drift and handles navigation. It's not meant for FunJets and flying wings, but for the kind of relatively stable aircraft most newcomers start with, it can perform well and be very easy to set up.

One example of this style is the UNAV PicoPilot, which was designed nearly a decade ago. We thought it was time to come out with a modern version, based on the faster GPS modules and better gyros available today, and make it open source.

Ideally it would be priced well under $200 with everything all included. It's USB-native and self-contained, requiring no additional parts--it just a shield that plugs on top of the current ArduPilot, so it can use the standard groundstation and configuration utilities.

The above image shows the board design, which is close to going into prototype production. We may switch GPS modules to the 5Hz Locosys (Mediatek) module before we release it (cheaper, possibly better performance with the small patch antenna), and we're going to test the 25mm ceramic patch antenna vs the 18mm antenna to see how much difference they make.

Jeff Turner and Scott Plunkett are leading this team, with board tweaking by Jordi Munoz.

We'd love your feedback at this stage!

The Eagle files are here:

Turnrate_shield_nice.sch

Turnrate_shield_nice.brd

Here is the data from my first flight test - ublox is blue, scp1000 is pink. The data was taken while manually flying a SkyFun "pusher jet" in somewhat gusty wind conditions.

There are several things that stand out to me. First is that the scp data is a lot "noisier". Does this actually represent the movement of the aircraft? Perhaps. I cannot really say after this one test.

Second is that the ublox appears to lag badly during fast descents. Seems to keep up going up, but not so much coming down. I suspect this has something to do with the ublox filtering algorithm.

The third thing I see, about which I am the most curious, is that something produced some kind of offset to the pressure at the beginning and end of the flight. If you look closely at the beginning of the graph, you can see that the pressure altitude starts at the same value as the gps altitude (by definition in the software). However, while still on the ground, something causes the pressure altitude to jump down about 22 meters. It bounces back and forth for one period before takeoff. Then at the end of the flight, you can see that the landing altitude is about 22 meters below actual, but then something happens on the ground that causes it to bounce back up around the correct value. This is a real problem. My only theory so far is that putting the canopy on may be trapping some small amount of pressure. However, if this were the case I don't know how the sensor would have the relative level of accuracy it does during the flight. The effect does not appear to be related to airspeed, as the changes noted at the beginning and end were while not in motion.

I also noted that except for the bottom of the "second valley", the effect I noted above, if it is coming and going, could produce the "noise" seen in the pressure altitude. You can see that the peaks of the "noise" correspond fairly well with the gps altitude for much of the flight.

I welcome all thought and comments.....

I'm giving away $1,000 in robot prizes to celebrate the 10th birthday of my robotics blog, GoRobotics.net, this month! To enter, just post a comment with a link to your best robot here: http://www.gorobotics.net/the-news/robot-giveaway-10-years-of-gorobotics-1000-in-prizes/. Big thanks to our sponsors Pololu, Trossen Robotics, Zagros Robotics, Solarbotics , Vex Robotics, Apress, and No Starch Press.

Here's the prizes:

Grand Prize –Vex Dual Controller Starter Bundle with RobotC (donated by Vex Robotics), Pololu Jrk 21v3 USB Motor Controller (donated by Pololu), Build Your Own CNC Machine (donated by Apress), LEGO Mindstorms NXT One-Kit Wonders (donatedby No Starch Press). ($605 total!)

2nd Place Prize - Penguin Robot (donated by Trossen Robotics), Extreme NXT(donated by Apress), Wall Hugging Mouse Kit (donated by Zagros Robotics), LEGO MINDSTORMS NXT Thinking Robots (donated by No Starch Press) ($268 total!)

3rd Place Prize – Oomlout Arduino Experimenters Kit (donated by Solarbotics),Practical Arduino and LEGO Mindstorms NXT 2.0: The Kings Treasure (donated byApress), and The Unofficial LEGO MINDSTORMS NXT Inventor’s Guide (donated by No Starch Press) ($165 total!)

Hope to see lots of flying robots posted! Good luck. Don't forget to post your comment here: http://www.gorobotics.net/the-news/robot-giveaway-10-years-of-gorobotics-1000-in-prizes/