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3D Robotics

DIY Drones passes 10,000 members!

A big milestone for DIY Drones today--we passed 10,000 members!


On average, this site gets 12,000 visitors and 25,000 page views a day, or 300,000 visitors and 700,000 page views a month. The biggest country by far is the US, but even that is only a third of our traffic. The rest of the top ten is below, but note that the rest of the world beyond that accounts for another third of the traffic. The amateur UAV world is a very long tail:



We continue to gain 1,000 member every 2.7 months. After we instituted some tough spammer-control measures at the beginning of the year, it slowed down for a month, but now it's speeding up again. Every one of these members has been reviewed by a moderator; I hope you notice the near-total absence of spam as a result. Thanks, moderators!


And thanks to all 10,000 of you---this community was created by the members, and it's a thrill to watch it grow and take new shape each day. And a special thanks to Morli, whose role as head moderator is perhaps one of the most important here, even though it doesn't show up in the code or PCB boards. The key to great community development is great community management, and our growth while keeping the signal/noise ratio high is a tribute to the job Morli is doing.





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Loading a Waypoint in the Air with XBees

Hey everybody, me and my friend Chester would like to share our implementation of loading a waypoint into the ArduPilot in air. We use XBee radios, NewSoftSerial, and our own GCS written in Java (using Andrew Rapp's xbee-api) to do this. Our GCS was originally designed to facilitate a collision avoidance system for multiple UAVs (this is part of a research project at Auburn University), but we've added a small GUI to allow the user to type in their own waypoint to push to the plane.

In the ArduPilot code, we added a function to poll the XBee for a waypoint packet (we give it a data type of GCS_packet_t) in the 3 1/3 Hz loop. The XBee's TX pin is hooked up to analog4 (one of the few pins we found was not in use) via NewSoftSerial and runs at 57600 baud. If it has a valid packet, it replaces the ArduPilot's next waypoint value with the one from the packet. After it hits this new waypoint, it loads the old next waypoint back in from EEPROM and continues on its original path.

We tested this in our setup with a Multiplex EasyStar, an ATmega328-based ArduPilot running 2.6.2 modified with our code (compiled in Arduino 0018), and an EM406 GPS also at 57600 baud. We are ArduPilot newbies ourselves, but we think everything worked to our expectations.

Our code is available at this github: http://github.com/wjwwood/au-proteus. In the ArduPilot_2_6/ folder, you can find our modified ArduPilot code, along with an extensive guide (XBee_Guide.txt) written by Chester on where the changes are and the rationale behind them. In the xbee-api/ folder, you can find a Readme for the GCS code (XBeeGCS_README.txt).

While we'll be leaving our research program in a few days and not be able to work directly with the planes at Auburn anymore, we'd be glad to hear your comments on this work. Cheers!
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PC based autonomous boat

Overview:
This project is in the very early stage of development. I've got a couple ideas that I want to explore and need a suitable platform to work with. The following are some of the components I hope to use to assemble this platform.

Objective:
The objective of this project is to design a very small boat ( roughly 1 meter LOA ) that will be capable of autonomously traveling a preset survey grid to produce a sonar bottom scan. For this first iteration of the project I hope to use all off the shelf components, the only customization will be some custom code I will need to write.

Components:
CPU
HP Mini 311 - The brains of the boat. Probably over kill for the task, but I happen to have one.

Operating System
Windows XP - Mostly because of the wide range of free tools and info available for it.

Control Software
RoboRealm - This very cool software is really a key element to the whole system. It supports a wide variety of hardware (servo controllers, GPS sensors, serial interface, etc.) and provides a simple interface for making them work together.

Motor / Servo Control
Parallax USB Servo Controller - This will be used to control the boat's propulsion motor(s) and rudder(s).

Sensors
GlobalSat BU-353 USB GPS - The GPS will be used primarily to provide position, course to steer and distance to waypoint. It will not be used for heading information as GPS heading is almost completely worthless at slow vessel speeds.

Silicon Labs USB tilt compensated compass - A very inexpensive, tilt compensated, USB interfaced compass that I just happen to have.

Route planning
Polar View - A free chart viewer, route planning application. A track can be marked on a chart and then saved as an ASCII CSV file, which will then be used by the autopilot software I hope to write.

Remote monitoring / Control
Wifi + VNC - My plan is to use a 1 watt router connected to my shore based computer, and then a 1 watt USB dongle network adapter on the afloat computer. The goal will be to be able to monitor the boat's position and sensor data as well as being able to update/change the autopilot's route. I have no idea what the potential range is for Wifi over water, but hopefully 1 watt will give me at least a couple hundred meters.

Boat
I'm still sorting this out. I'd prefer to use something off the shelf (ie. a large RC boat) but most don't have the weight carrying and stability capabilities I will need. The hull will likely be a catamaran or trimaran and propulsion will be by electric motor. The final system will need to be hand carried by one person, so the size will likely stay at roughly 1 meter LOA.

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For a long time I've been wanting to make an ultra minimalist vision / optical flow sensor for the hobbyist and experimentalist community. I've been pursuing this as a small IR&D pet project at Centeye. We're almost there.


The above photo shows one of these sensors next to a millimeter scale. The part count is small- One of our 64x64 custom image sensors, an Atmel ATmega644 processor, several resistors and capacitors, and some lightweight flat optics we developed. Two complete sensors are shown, including with mounted optics (yes it's that thin!). Total mass is about 440mg. The primary interface is via I2C/TWI, which will allow many sensors to be hooked up to a common bus. A secondary connector includes the interface with the ISP for uploading firmware.


We chose to use an ATmega processor since they are loved by hardware hackers and are easy to use. Ideally for a single sensor, one can upload any number of different "application firmwares" to the sensor to make it whatever one wants, limited by just the processor and the base resolution. One firmware will turn it into an optical flow sensor . Another firmware will let it track bright lights. Yet another firmware could turn it into something else. Or someone could write their own firmware, whether by tweaking existing source code (yes I plan to share it) or writing something completely new.


An ATmega644 may not sound like much for image processing- 64kB flash, 4k SRAM, 2k EEPROM, 20MHz max. Neither does a 64x64 array. But the reality is if you are witty you really don't need at lot of resolution or processing power to get some nice results. (We once did an altitude hold demo with just 16 pixels an 1MIPS back in 2001.)


We've already made our first batch of these (about 20) and handed them out to a few close collaborators. Based on feedback we are preparing our second run. The new sensors will be slightly larger and heavier (thicker PCB) but more rigid, and use strictly 0.1" headers for all IO and power (including programming). Mass should still be under a gram.


We also have an even smaller version in the works, shown below with a chip mounted and wire bonded (sorry about the mess). This board uses ATtiny and the 7mm x 8mm board alone weighs about 95mg. I think we can get a whole sensor made for about 120mg, if only I had the time! (Maybe some brave person here would like to take a stab at programming it???)


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Just wanted to inform you all that I have sucessfully modded and flown William Premerlani's UDB2 board (red board) with the invensys gryo board designed by Russell Duffy. The AP / stab code was MatrixPilot r466 and the planes were a Fun Jet and an Easystar clone (higher wingloading and with ailerons).



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3D Robotics

Our buddy Nathan Siedle, the CEO of Sparkfun, has started a great series of posts documenting his high altitude baloon project. It starts here, but the really cool geek-out over sensors and wireless starts here.


Here's the custom PCB:



Sensors include:

  • GPS
  • Accelerometers
  • Pressure
  • Temperature
  • Humidity
  • Ambient light
  • Battery level


Plus long-range wireless modems and onboard datalogging.


Sadly, the wireless link was lost and the balloon and the electronics are somewhere in the plains of Eastern Coloradao.


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3D Robotics

From Wired.com (which I don't run, btw--I just run the sister division, Wired Magazine), a good article explaining why the apparently underpowered Arduino has proven more successful than more powerful computing boards, such as the Beagle Board. Excerpt:


"The Arduino community is at least 100,000 users strong. But it is not alone.

Other open source projects like the BeagleBoard, which is shepherded by Texas Instruments, are trying to win Arduino fans over.

The Beagleboard is a low-power, single-board computer, whose latest version is based on the same 1-GHz ARM Cortex A8 processor that drives the most sophisticated smartphones today. That gives it far more processing power than the Arduino. Yet the BeagleBoard hasn’t hit the same kind of chord with hardware hackers that the Arduino has.

“The BeagleBoard is not for a novice,” says Phil Torrone, senior editor at Make magazine and creative director at Adafruit, a company that sells DIY electronics and kits. “With an Arduino, you can get an LED light blinking in minutes.”


Five reasons are given for Arduino's success:

  • Starter projects
  • Costs and durability
  • A thriving community
  • Maturity is key
  • Simple is attractive


Read the whole thing here.



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Moderator

PIANFORMOSA 26 6 2010 promo from Tittap123 on Vimeo.


Thank to Mario for this beautiful day and Tittap for his Great Video :)

for more info .. power point and for meet the people in the video meet us 8 July at 22.00 PM (ROME TIME) in our first skype conference add VirtualRobotix to your skype firends http://www.virtualrobotix.com ;


Roberto

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3D Robotics

Military drones beset by problems

We don't cover military drones here, but I thought I'd make an exception for this excellent LA Times article, which shows that the pros have as much trouble with their UAVs as we amateurs do!


Some highlights:


"Thirty-eight Predator and Reaper drones have crashed during combat missions in Afghanistan and Iraq, and nine more during training on bases in the U.S. — with each crash costing between $3.7 million and $5 million. Altogether, the Air Force says there have been 79 drone accidents costing at least $1 million each."

...

"At least 38 drones are in flight over Afghanistan and Iraq at any given time."

...

"At least one drone crashed because it had no fuel gauge, and the aircraft ran out of fuel. In another crash, investigators cited a design flaw: The "kill engine" switch was located next to the switch to lower the landing gear, and a ground-based pilot confused the two."

...

""These airplanes are flying 20,000 hours a month, OK?" said retired Rear Adm. Thomas J. Cassidy Jr., president of the aircraft systems group at General Atomics Aeronautical Systems in San Diego, which makes Predators and Reapers. "That's a lot of flying," Cassidy said. "Some get shot down. Some run into bad weather. Some, people do stupid things with them. Sometimes they just run them out of gas."

...

"On Sept. 13, a pilot inside a ground station in Nevada lost video and data links to a Reaper over Afghanistan. As it was about to exit Afghan airspace and crash, an F-15 pilot was ordered to shoot it down and ground troops recovered the wreckage to keep top-secret technology out of insurgents' hands."

...

"After a Predator crashed during a landing at Kandahar air base in March 2007, investigators faulted the Predator system for a "lack of visual cues" to help pilots understand the position of a plane flying half a world away. The pilot in Nevada misjudged the drone's altitude, the investigative report said.

The Predator that ran out of fuel over Iraq had a leak, but there was no gauge to warn the pilot, an Air Force crash researcher said. And a pilot trainee at Creech Air Force Base in Nevada crashed a Predator by hitting the "kill engine" switch instead of the adjacent landing gear switch, according to an investigative report.

Some ground control stations, where pilots and camera operators sit, still have 1990s-era text-based computer systems. Pilots have to type function and control commands rather than clicking on icons.

"There's a control delay between typing something and having it actually happen on the airplane," said Gregg Montijo, a contractor who trains drone crews. "When the heat is on, sometimes guys will type something in, then type it again real quickly. They'll confuse the computer and get the wrong display and get into a vicious cycle."

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BEAM navigation

Phototropic_2m_walker.gif

This is the circuit for a phototropic walking robot insect which follows light.
It's based on M.Tilden's work, BEAM robotics: it's about analog control circuits (microcores) that simulate neural and nervous networks present in the in the real insects' spinal cord; these react to external stimuli in a robust and very reliable way. Many other circuits have been drawn to do things like follow light, sense obstacles and reverse motors.
Of course this works just for walkers for the moment.

here comes my project: a BEAM autopilot!
It will be based on conversion of digital data coming from sensors, GPS to analog current levels, that will be inputted to control circuitries like the one above. The outputs will then be reconverted to digital for actuating servos and so on. I haven't still drawn nor calculated anything.

This is just a newborn concept, now I'd like to hear opinions of feasibility from experts in electronics I'm such a stinky newbie!

Thanks to everyone who will give me some thoughts!!
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Custom helicopter IMU

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I soldered together the helicopter IMU after the long wait for the board (It was worth it, batchPCB doubled my order). The only things not connected is the camera, GPS, Wireless transmitter, MAG, and pressure sensor. All of these go off with cables to various parts of the helicopter. I still have two expansion ports available on seaperate cores available, the only thing planned for the first core is the wireless connection (all other mentioned sensors connect to the shield), and the second will be a memory controller for external RAM, in order to proccess larger images.
You can see the ADC's poking out, one samples the gyros and the temperature outputs on the gyros, and the other does the accelerometer. I have some spare analog inputs, as well as around 12 digital spare (6 broken out on board).
Got all the helicopter parts, but on first spin up, the tail blade got stuck in some blankets and destroyed the belt transmission gear.
I did some surgery to remove a bad cell from the 6s 5000mah battery I got from hobbyking, ended cutting open a cell to get it off as its glued together very well. Very nerve-racking.

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3D Robotics

Book review: Skunk Works

I just finished a terrific book that should be an inspiration to aircraft engineers everywhere. It's called Skunk Works, and it's an inside story of the peak years of Lockheed's now-famous secret development lab, which created the U2, SR-71, and Stealth Fighter. Although first published in 1994, it's still a totally gripping read, full of anecdotes of Cold War air battles and engineering heroics. Think "Soul of A New Machine" but about spy planes. I couldn't put it down.

They also created the first reconnaissance UAV, a jet-powered Mach 3+ drone called the D-21 that was launched from a B52 and designed to overfly Russia or China, dropping its film canister by parachute to be recovered before self destructing. This was before GPS, so the drone used a sophisticated star-tracker for navigation. Although it flew five missions over China, problems with the film recovery process led it to be cancelled.

A couple cool tidbits: the big breakthrough on stealth was the discovery (from an obscure Russian scientific paper) that the radar signature of a flat object was the same (and small) regardless of its size. Thus the faceted shape of the Stealth Fighter, shown on the cover at right. The fact that computers in the 1970s could only calculate shapes with big polygons also contributed to its distinctive shape.

It's co-written by Ben Rich, the chief of the lab for much of that period. Highly recommended!


Here's the Publisher's Weekly description:

"Lockheed's Advanced Development Project has set standards for the aerospace industry for half a century. Under its presiding genius,
Clarence "Kelly" Johnson, the Skunk Works produced America's first jet
fighter, the world's most successful spy plane (U-2), the first
three-times-the-speed-of-sound surveillance aircraft and the F-117A
stealth fighter. Rich was Johnson's right-hand man and succeeded him as
director in 1975, retiring in 1990. In an entertaining style, the
authors describe Johnson's tyrannical managerial style, his thorny but
productive relationship with the Air Force and the stealth-technology
breakthrough that revolutionized military aviation. Writing with
freelancer Jonas, Rich also recounts Skunk Works' failures, including
experiments with liquid hydrogen as a propellant and spy-drone flights
over China's remote nuclear test facilities. He has much to say about
the Defense Department bureaucracy and warns, "Everyone in the defense
industry knows that bureaucratic regulations, controls, and paperwork
are at critical mass... and... in danger of destroying the entire
system." This is a significant book for those interested in aerospace
research and development."
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Moderator

Dear Friends,
this is the first video of Java GS by Riccardo Ferrari (Fox Team) in action.
Java GS using RPC Server architecture implemented in Arducopter Redfox74 branch.
This is new approach to Groundstation for people that prefer completly opensource architecture instead to use labview. In the next revision of Arducopter i think that we implement this code as experimental , activable by DEFINE .
Regards
Roberto N.
FoxTeam : www.virtualrobotix.com


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Around the world with no fuel!

Hi Guy's,

Way off topic but.... How cool is this!

These guys have built a solar plane that has the potential to stay up for ever with no fuel!!

The will attempt to fly it through the night in the next week or so.

Here is a little video from their YouTube channel. Cheers!

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My New AGV



You might remember the old one, which was just a prototype, this one is much better.


The new really big difference is the vehicle (you can see the name of it on the truck every where). I am pleased with the truck, a lot better than my $20 Rc hummer i was using before. This one has plenty of power to drive up inclines and through grass even though i still would only like to drive it on concrete or asphalt.


Also i made some custom PCBs for this purpose



If your interested in a PCB, i have extras i want to get rid of for $6 and free postage in the USA. If you want one then send me a message.


Here are the parts that go on the board:


I will be working on the code for the next few days. I have ran test code and rough AGV code and my custom board is working fine.

I bought a 3"x 2" x 1" plastic project box from Radio Shack and cut a few different holes for cables to go through. My custom AGV PCB goes inside.

The ESC, servo, and UBEC wires go through a hole in the top of the truck that was meant for the antenna.

The box is attached to the bed of the truck using velcro and the GPS is attached to the box using velcro

Here it is all finished. Just like before, the compass is mounted high in the air away from any magnetic interference from the electronics and motor.



I will post some video hopefully next week.


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