Blogs

https://www.youtube.com/watch?v=Nmp4zzl2pfo

Some of us, do not live in California with 300+ sunny days in a year, and have to cope with rain and bad weather. The new watertight Fujitsu Arrows Tab looks to be perfect for such days.

By the time we reached the ghost town Gold Hill near Reno, our equipment was pretty heavily beat up from all the travelling. Please excuse the waves in the picture, our props have beaten themselves through heavy gravel and forests to reach this place, they deserve a little bit of vibration :)

After reading about the crowdsourced UAVforge.net competition here on DIYDrones, I conjured up the audacity to enter an Arducopter into the fray.  Since then, the field has been reduced to 20 teams competing for 10 slots in a fly-off scheduled for May.

After some trial and error, I was able to assemble an Arducopter capable of completing the competition course. I passed the required live, directed demo indoors during a snowstorm last week.

Since it has a crowdsourced component, I need some votes (likes) on the UAVforge website to help make it to the fly-off.  If you believe my entry has merit, I'd appreciate your vote.

Team Phase Analytic

http://www.uavforge.net/uavhtml/#

Please forgive the poor videos as I had no "file footage".  It seems as though no one else I know is fascinated enough to stand and film endless loiter tests and PID tuning rituals...

If I am lucky enough to secure a slot in the fly-off, I'd like to invite at least 2 of the Arducopter Dev team members to the expenses paid trip to Georgia.  It would really be their victory more than mine.

Any suggestion or criticisms are welcome.  I am just a fellow hobbyist.

Thank you!

arashi

Team Phase Analytic

The deadline for the current T3 competition (auto takeoff and landing) is Sunday night! I know it's still winter in much of the world, but let's get some more entries in. Right now only the UDB team has got their act together with a some impressive missions like the above. And we don't have any multicopter entries are all :-( 

Get out there!

My latest autopilot with new ADXRS453 gyros is ready for testing.

- Two switching power supplies (Traco Power) at 6.5V and 5V for low power dissipation

-  Separated reference voltage with RLC filter for sensors

-  Separated reference voltage with RLC filter for ATXMEGA's ADC reference input

-  Separated power supply with RLC filter for MCU's digital side

- Two MCU's  ATXMEGA128A1 @ 40Mhz (40+40 MIPS), one for AHRS and one for navigation

- ADXRS453 ultra high vibration rejection gyros, digital output (SPI)

- LIS344ALH Accelerometer

- HMC5883L  3D Compass

- MPL3115A2    I2C Precision Altimeter - internal ready calculated altitude !! - saving MCU time for other tasks

- 6 R/C inputs

- 8 PWM outputs (460Hz)

- 2 PWM outputs for servo camera stabilization

- 8 digital outputs (500mA/each) for buzzer, external LED's,payload trigger,etc

- 2 spare analogical inputs @ 12bit

- 4 general purpose I/O's (I2C, UART, PWM)

- battery voltage monitoring

- Serial COM. for GPS

- Serial COM. for XBEE

- Serial COM. @ analogical input for ultrasonic Sonar

- Four LED's for GPS,XBEE,etc.

I will start doing testings with the AP in high vibration environment - by using unbalanced propellers + motors and see how well gyros will perform. In following days, MPL3115A2 will be also delivered. Just waiting to see the altitude precision of  this new IC.

Will keep you posted about testing results.

Cheers,

Sergiu

Hi all,

after a lot of research, programming, setting and tuning, I'm proud to announce that my Proxima II went in flight.

It was already, but without any autopilot, only to set the right controls, trims, CG and wings angle of attack.

Now it is fully autonomous. This is the more complex autopilot equipped plane I ever build.

Here you can see the plane in full action.

In this video there is a demonstration of the controls possibilities.

The pilot has the following controls over the plane :

• throttle
• elevator
• rudder
• ailerons, differential !
• flaps, with those functions : thermal flaps, crow flaps
• autopilot mode
• coming next will be camera pan / tilt and camera mode controls

Possibilities are :

• roll control over two (ailerons) or four surfaces (ailerons and flaps)
• camber control over four surfaces (I could program it over two surfaces too, but actually I don't need it)
• crow flaps, with roll control over two or four surfaces
• fine trimming of both ailerons and flaps for roll or camber

About the plane :

Proxima II, 2.78m, Selig 3021 (Reichard)

MVVS 3.5 / 1200

Castle Creations ICE 50A ESC

Thomas Scherrer RC system

UavDevBoard 4 stabilization / autopilot unit

And finally an amazing board that allowed me to have all those functions mixed with the autopilot.

FpvKiwi Channel Wizard

This mixer is incredibly flexible in programming.

It is fed with PPM stream from RC rx. The UDB is daisy chained to it and feeds back to it again ailerons control for stabilization and autonomous flight.

Here are the schematics of all the connections :

Here you can watch some more pictures of the plane.

Next plans are to mount a video system and use it as an FPV platform, for long time flying using thermals.

This plane is dedicated to Bill Premerlani, as a tribute to him for starting this amazing adventure, for all the improvements he achieved and for letting me the privilege to travel a short distance on this long road with him.

Thank you Bill !

Best regards,

Ric

I tested the auto landing feature on the APM I've installed on my Nova. Unfortunately, something has gone awry with the APM (the ADC may have failed) and the APM couldn't load the accelerometers or gyroscopes, causing a stabilization and auto flight mode failure.

I'll be repairing that as soon as possible, and work on getting the Nova back in the air. Meanwhile, I'll do some FPV flights to see if I can't start getting the hang of that.

See you next week!

-Trent

Equipment Used:

Airplane: Scratch-built Nova, see http://www.MyGeekShow.com for plans and build instructions

Main Camera: iPhone 4s

Airplane Camera: FlyCamOne2

Motor: http://www.hobbypartz.com/75m55-optima450-2220-1800kv-2.html

ESC: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=13429

Battery: http://www.hobbypartz.com/77p-sl4400-3s1p-30c-3333.htmlidProduct=6306

Servos: http://www.hobbypartz.com/topromisesg9.html

Prop: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=5437

Stats:

Weight: 32 oz

Thrust: 21 oz

Wing Area: 3.33 square feet

Wing Loading: 5.3 oz per sq ft

If you're interested in building the Nova, I've got free build instructions and plans on my website: http://www.MyGeekShow.com.

The New America Foundation had a conference in Washington DC last week called "Tinkering with Tomorrow: Will the DIY Movement Craft the Future?" 

The full conference is recorded in the video above, but check it at at the 30:00 mark, when Tom Kalil, the Associate Director of White House Office of Science and Technology Policy, singles out DIY Drones as a great example of "cyberphysical systems". That's defined as very low-cost hardware and embedded software--a physical device with sensors and actuators, connected to the network. "A huge amount of innovation is going to come out of this", he said. 

NASA and Lockheed Martin have teamed up to create the X-56A, which is designed to use sensors and fast-response control loops to stop wing flutter, which can be a killer in high-aspect ratio wings. From Wired's DangerRoom:

When flutter does occur in the X-56A’s slender wings, the on-board flight computer will manipulate the flight control surfaces on the wings in an attempt to reduce it. Although some fly-by-wire aircraft have been able to reduce the oscillations, the typical solution is to simply increase the strength (and weight) of the structure.

If successful, new designs could lead to ultra lightweight structures and extremely efficient wings for future high altitude drones expanding the capabilities of the eyes in the sky.

The research could also make its way into the civilian world. Because strength, weight and efficiency are interlinked, many futuristic designs promoted by NASA and others rarely go beyond the design concept stage because there is no way to safely use lightweight structures that lack the strength to handle potentially destructive things like flutter.

From IEEE Spectrum

Here's a quadrotor with giant spindly bird legs from the Utah Telerobotics Lab. It's a passive system which uses the weight of the robot to actuate the grippers, so that when the quadrotor lands on something it latches on and stays. To release, the robot just lifts off, and the grippers let go. Birds use a very similar system to keep themselves perched while asleep, and the leg and toe design was inspired directly by songbirds.

[ Utah Telerobotics Lab ]

Here's it flying:

This is a little off-topic for us, but here's a new achievement in aeronautics: a new paper airplane distance record of more than 266 feet. I'm particularily proud of our former University of Berkeley quarterback who had the winning throw. There was a little sticky tape on the plane, which is allowed by the rules, so it's not 100% paper, but the competitors are being gentlemanly about it..

Hizook has a great analysis of VC funding for robotics companies in 2011. There isn't as much of it as you might expect (note that only one is for a UAV company, Helen Greiner's CyPhy Works, which has yet to release a product). Here's his explanation for why:

My hope is that robotics will get more love in the next year(s), but getting VC funding for robotics is a decidedly tough nut to crack.  Robotics companies have large capital requirements for robot hardware, few potential acquirers, and almost no "Google-scale" breakout success stories (ie. IPOs).  I mean, c'mon... one of the best known robotics companies, iRobot, has a market cap of just $700 Million.  This makes robotics a difficult sell to your typical VC firm.  My hope is that this list can give others courage to pursue "swing for the fences" type projects along with a source for robotics-friendly VC firms.

This great talk, given yesterday at TED, is now live. I was here and the crowd was wowed. Check out the lovely math on simplifying the 12-dimensional math to 4 dimensions at around the 5:00 mark, 

    Just finished building an almost production quality heavy lift foldable Y6 frame.  Bare frame without electronics and motor mounts is 327.4g.  All frame parts are cnc machined.  The motor mounts are molded out of light weight fiberglass reinforced plastic (rear mount), and light weight graphite reinforced plastic (front).  

    The idea was to build a strong, lightweight, foldable, heavy lift platform at the bare minimum of cost.  All the components are covered and protected by an ultra lightweight fiberglass body set.  I was using carbon for the prototypes, but later opted for fiberglass to limit interference issues so everything could be enclosed within the body.  The carbon body weighs in at 80g a piece.  The Fiberglass body weighs in right around 45g (90g for both halves).  

    The arms are 16mm carbon fiber cello wrapped tubes.  The arms have almost a 2mm wall thickness, which makes them virtually indestructible.  40-50% of the arms weight can be drilled out for further weight saving without compromising structural integrity in flight.  The sub-frame assembly was cut from 2.5mm peel-ply carbon fiber panel (very strong and rigid, but at half the price of traditional weaved carbon fiber fabric).

    Everything on this air frame is an original custom design, especially the landing gear.  I have built and flown a number of multirotors with varying success.  The quality and flight characteristics have continually gotten better with each consecutive build.  In a previous blog that I posted "Trilo-Byte preproduction prototype"  I tested the effects of using light weight shock absorbent landing gear.  Due to the efficiency of prototype landing gear I decided to incorporate them into this version as well.  Considering the amount of money that goes into an AP rig why do we still use stiff rigid landing gear when landings on even the best systems are all but perfect?  I believe that it makes perfectly logical sense to dampen the landing struts to minimize excessive force on expensive hardware and components.  The landing gears dampening systems can be adjusted with cheap inexpensive o-rings.  

    I am also finishing up on a production quality quad build using many of the same building techniques.  I have also designed a better method for mounting ESCs', which makes them more accessible and easier to replace in the event one fails; also greatly reduces wire clutter.  I will post the quad photos and subsequent flight videos once I have finished fabricating and mounting the landing gear.  

    The premise behind all of my designs are to make the highest quality air frames at the lowest possible price, but most importantly make them easily serviceable with readily changeable and easy to produce parts.  Best of all, I design my frames around the ArduPilot hardware.   I will post videos and more photos soon, along with more specs.  

Feel free to post your comments, questions, suggestions, or criticisms.  All feedback is appreciated.   

I have an old BNB Digital Power recorder so I wanted to have a look at the hovering power requirements of my quad. The weight of the quad with either battery is very similar.

Quad specs:

APM2

KDA20-22L motors from Hobbyking

2 x Super Simple 25-30A ESC's from Hobbyking

2 x Hexfet 25A ESC's from Hobbyking (2 of 4 were DOA)

10 x 4.5 props from Goodluckbuy.com

Batteries: 4S 2200mAh Nanotech 25C

3S 3000mAh Turnigy 25C

X525 frame

What vibration can do to your model (1:1 example)

The smallest computer to run Linux?  I think this has a LOT of potential..all the sites selling it are down due to traffic volume...

More here:

http://www.raspberrypi.org/#top

:-)

I've been working towards a realistic simulation of my high-altitude return-to-launch glider project in X-plane and this is the latest result which some here might find interesting.

The simulation is running with X-plane 9, APM-MP 1.1.36 (to keep the TAS into APM - more on that later) and a slightly modified version of ArduPlane 2.28.

To achieve the drop, I drag the aircraft up to the release altitude using the Local Map feature in X-plane and set the speed to zero.  Whilst this isn't a perfect simulation of the intended release due to the flat orientation of the aircraft, for my purposes it is sufficient for now.  Initially I allow the aircraft to accelerate in Manual mode until about 25kt IAS, then I switch to Stablize, manually manipulate the controls to pull out of the dive as rapidly as practicable before proceeding to switch into Automode.  Eventually I need to code this whole process to trigger and execute all automatically in APM.

On this drop, I set the release point to be about 80 miles 'upwind' of the simulated launch point to make a rough allowance for the drift of the balloon on ascent.  I am using the X-plane's real weather simulation (where it gets its weather data from some unknown on-line and quasi-real-time source), so I couldn't be absolutely sure what the headwind was going to be.  This was the third in a series of flights, where the release point was selected from the experience of the earlier flights to give a likely head wind for the whole descent glide stage.

As you can see from the Google Earth image above, most of the travelling is done above the jetstream altitudes and the aircraft arrives at the loiter point still at nearly 45000 feet!

I logged the data using the data output to file feature in X-plane and then created a KML file using this method which uses this on-line file translator.  Whilst logging the data in X-plane, I added more than just lat-long-alt and included some airspeed data so I could figure out a few other things.

The altitude profile shows the entire descent stage lasting a little over two hours:

and, the speed profile is here.  You can see how the ground speed is fluctuating wildly as it tries to hold the loiter position.  I'm not sure if the peak airspeed of nearly 500mph is achievable either because I didn't make a note of the Mach number, but it was probably less than 0.85.  I suspect this could be an issue for airframe integrity...

More work needed here to limit the speed during the dive phase.

Finally, I integrated ground speed to give me an estimate of the distance I could feasibly travel from the release point.  A pretty impressive number, don't you think?  Line of sight all the way too! ;) 

...and before I forget, here's a few details on the TAS problem I mentioned earlier.

The APM-MP-based HIL simulation up until recently has fed APM with true airspeed (TAS) from the X-plane data.  I need this primarily for the PID loop speed scalar to allow stable control at high altitudes.  The only problem is that this isn't what APM gets in real life from a pitot.  The pitot-static system will give you indicated airspeed (IAS), or more correctly, dynamic pressure, which deviates wildly from true airspeed as density changes.

Michael Oborne has changed this in a later version (1.1.42 at least) so that APM now sees a realistic IAS number from X-plane, however this would mean I'd have to implement the IAS-TAS conversion in the APM code.  I must do this at some stage, but for now having this little MP bug is a handy thing! :)  Lazy?  Moi...?

The APM software mod I've done is an embarrasingly simple one (yes, it's true I'm not a software geek!) where I expand the speed scalar clips from the standard 0.5-2.0 to a randomly selected 0.01-5.0.

http://www.suasnews.com/2012/02/12471/double-o-drone-grasp-lab-plays-bond/

Quadrotors designed and built at the University of Pennsylvania perform the James Bond Theme by playing various instruments including the keyboard, drums and maracas, a cymbal, and the debut of an adapted guitar built from a couch frame. The quadrotors play this “couch guitar” by flying over guitar strings stretched across a couch frame; plucking the strings with a stiff wire attached to the base of the quadrotor. A special microphone attached to the frame records the notes made by the “couch guitar”.

These flying quadrotors are completely autonomous, meaning humans are not controlling them; rather they are controlled by a computer programed with instructions to play the instruments.

Penn’s School of Engineering and Applied Science is home to some of the most innovative robotics research on the planet, much of it coming out of the General Robotics, Automation, Sensing and Perception (GRASP) Lab.

This video premiered at the TED2012 Conference in Long Beach, California on February 29, 2012. Deputy Dean for Education and GRASP lab member Vijay Kumar presented some of this groundbreaking work at the TED2012 conference, an international gathering of people and ideas from technology, entertainment, and design.

Now with a loop at the touch of a button and USB port that allows you do grab your HD images.

The AR.Drone is beginning to be a useful platform, not long before every builder has one.

http://www.suasnews.com/2012/02/12433/pre-orders-to-open-march-1st-for-ar-drone-2/