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In my focus on the Lego UAV, I forgot to mention that I've also uploaded the Visual Basic source code for our cellphone autopilot. It's in pretty good shape, and just needs a little more tweaking for reliable airbone use. If you're comfortable with Visual Studio and Windows Mobile, this is a great starting point for cellphone-based aerial control, communications and imaging. The code is here.

Anybody recognize where I stole the image that is on the program's opening splash screen? (Shown here on the Windows emulator. Weirdly, the emulator blocks screen shots, so I had to photography the screen. Apols for the poor quality...)

You may have missed it in the discussion threads at left, but Howard Gordon has been doing some terrific work combining his robot and camera control boards with UAV platforms. The latest uses the quadcopter platform that the X-UFO/X3D guys in Germany developed. Check out his full post here.

Keep us posted on your progress, Howard! (Here's hoping you'll offer the components for sale, too, once you've got it done.)

Go here first. http://www.click2houston.com/investigates/14659066/detail.html

Is more being made of this than is necessary?? I wonder why the reporters spin did not point towards the environmental benefit of UAV's less gas than the helicopter. The newscopter that was chasing, is that not invading the privacy of some police officers on a private farm??

Newscopters falling from the sky constitute quite a danger to the public, as last years crash in Phoneix Arizona proved.

So is raising the privacy issue, the pot calling the kettle black. Whats newsroom rights for one, is police invasion for others.

But I certainly agree that since 911 many basic human rights and freedoms are being lost worldwide under the banner of anti terrorism. Many of them just plain dumb. If you have flown internationally recently you will know the pain that is the new liquids rule.

All liquids that can be picked up once your through the security gate in duty free. Perhaps the sale of clear plastic bags world wide has gone down, so something needed to be done to lift them.

What really worries me here is that UAV's are being shown in a sinister light. The ability of UAV's to do dangerous, dirty difficult jobs at a lower cost with less risk to life should be emphasized at every turn.

Otherwise everytime you take your Lego autopilot out to play in your black van wearing shades you might come under TV Helicopter scrutiny. Perhaps Lego should be banned, thats the answer. It clearly demonstrates an invasion of your neighbours privacy.

I don't care if I'm lost in the hills or out to sea and a UAV, blackhawk helicopter or Buck Rodgers in his space ship hove over the horizon to find me, just as long as I am found.

Its no secret that the UK CAA may impose restricts on aircraft less than 7KG in weight with UAV equipment onboard.

Heres an extract from a 2004 policy document.

This policy is applicable to all types of UAV

Systems, including those of novel design.

UAVs under 7kg mass fall within the Small

Aircraft definition of the Air Navigation

Order (ANO) [6] and are exempt from most

regulatory provisions. Such UAV Systems

are currently the subject of a further review.

by the UK-CAA and may be included within

this policy at a later date.

Civil Aviation Authorities are pulling standards together and the days of the amateur developer are probably numbered.

Newscopter pilots need not worry for their jobs as aviation grown ups have already spotted that the media would like UAV's and will probably close the loop before its even slightly opened.

Ho humm, suppose I must start my working day.

G

An amateur UAV maker in Los Angeles built a UAV designed to fly 21 miles, from Long Beach to Catalina Island and back. It was notable especially for having the motor moved to a pylon above the wing and a pan-tilt gimbal camera put in the nose instead (see picture). This thread about it on RC Groups is a great introduction to high-end UAV making, diminished only by being a few years old (and I don't know if they ever had the courage to attempt the flight. Given the costs--nearly $4,000--it would have been an expensive loss at sea if anything went wrong)

Anyway, in this post he provides a spreadsheet of all his costs. It's very instructive, and most of those costs have not changed in the past three years. Small sample below; full version here.

Tom Pycke, who is one of the more sophisticated UAV hobbyists, has a good post showing how to use the open-source Flight Gear simulator program to test your autopilot code.

He begins:

"A lot of people think they need great electronics skills, a lot of time, and embedded programming skills to experiment with Kalman filtering of IMU-data. Think again! The key to all your success stories is simulation!

One of the easiest tools that can help you with those simulations, is a great flight sim called Flight gear. It uses advanced aerodynamics simulation libraries, among which some were created by the NASA. Good enough for our purposes! On top of that, you can easily configure Flightgear to log all the data you need. I updated my config file to log the following variables:

• Roll
• Pitch
• Acceleration along the 3 axis
• Gyro reading along the 3 axis
• Heading
• Airspeed"

He includes sample VB code, too (yes, you can code a Kalman in VB!). Read it all here.

The cover of MAKE magazine this month is a how-to on "blubberbots", which are small indoor blimp UAVs (story only for subscribers for the moment--subscribe! It's worth it). You can buy a kit from the MAKE store for $99 that will allow you to build a limited UAV--it heads towards lights and has a bump sensor to retreat when it hits walls. But how much harder would it be to give them real navigation abiliites, triangulating off IR beacons or even using GPS (if your roof isn't too thick)?

Oh, and the back page feature of that issue is on me and my Lego UAV (blush).

Here's a picture of the CPU and motor assembly from the creator's website, where there are several other Autonomous Light Air Vessels (ALAVs) and robtics projects:

These scientists describe their UAV project at the South Pole. Sound familiar?

"Flying a mission is always a little scary. Tom, the project engineer and pilot, stands by with his remote control and flies it a little until a stable flight is acheived, then we engage the autopilot. The plane then turns and heads off into the distance, disappearing from view after about half a mile, and dropping out of radio contact with its computer base station after four miles or so. That part of the mission is the most scary, as we've nothing to do but wait for fifteen minutes biting our nails as the plane follows its plan.

We breath a sigh of relief when we regain the signal and see some coordinates on the screen, but only declare success once we've seen the machine, taken it smoothly back down to the snow, and downloaded the data its recorded."

Play around with Lego Mindstorms NXT enough and at some point you'll inevitably get frustrated with NXT-G, its graphical programming language of "blocks" that you drag around and connect with "wires". It's great for teaching kids the basics, but once they embark on anything remotely ambitious they're bound to run into trouble. Whether it's the crazy sprawl of blocks over the work area (even a simple loop can require screens of slow horizontal scrolling), the lack of floating point math or, perhaps worst of all, the total absence of debugging tools, sooner or later you're going to start longing for a proper programming language that uses, you know, text and stuff.

"if...then...else", "while", even "for...next" -- you won't know how much you actually like those constructs until you don't have them. For anyone who's ever programmed, there's nothing better for understanding programming logic than properly tabbed and commented code, all in a column of text as God intended. And for your kids, there's no time like the present to introduce real programming, using coding conventions that will be as relevant in the decades to come as they were in decades past.

The good news is that there are lots of replacement text-based languages for Mindstorms NXT, from Java to Lua (or, if you want to stick with visual programming, you can also use LabView, the professional-grade language that NXT-G is based on). Even better news: I'm here to tell you that one stands out from all the rest.

It's RobotC and it's simply fantastic. If you're not a C programmer, don't worry--aside from a few grammatical conventions, it could be BASIC. But where it really stands out is in the programming environment. RobotC's integrated development environment (IDE) includes real-time syntax checking, compiling and contextual help and auto-complete of functions and variables. It has an awesome debugger, allowing you to step through your program, set break points and watch variables, or just watch the code executing on the NXT brick. And its collection of instructional and sample programs is unmatched in the Mindstorms world.

To give you of sense of this, here's my Lego UAV code in NXT-G (here and here) and in RobotC (here).

RobotC got its start at Carnegie-Mellon, the nation's top robotics school, and the pedigree shows. But special credit should go to Dick Swan, who authored much of the current program. (Dick, get a home page so I can link to you!)

For the stuff that we're now doing, including integrating GPS via Bluetooth, there's nothing for Mindstorms NXT that can match RobotC for flexibility and ease of use. Plus if you want to teach your kids real programming, why not introduce them to a real programming language? C leads to C+, C++ and C#, which is a lot more than you can say for Java ;-)

(Aside: as I was re-teaching myself how to program in C, I was reminded about the funny logic of computers. -100 is > than -90. Is this true in all languages?)

If you ask me, this is better than NASCAR. The DARPA Urban Challenge (robot cars race though a town) is being webcast live now.

Very well done live video is here, with color commentators, helicopter views and tons of team cams. Go Stanford (pic)!

How long till we see something like this for UAVs?

Well good old Google as ever comes up trumps...

http://www.rrcc.org/downloads.htm

http://pages.sbcglobal.net/limeybob/

http://www.ajdesigner.com/phpwinglift/wing_lift_equation_force.php

I'm sure there are many others that people know about.

Perhaps there should be a page of useful software here.

G

It would seem that being +30 at 4000' means something, which of course I already knew, but just what is the drop in performance on a 50 odd inch wing trainer??

What magic program or website could tell me that to lift lets say an extra 1KG of equipment at a density altitude of 7000' the aircraft would need to be X wingspan with Y power up front??

There must be something out there that will tell us such things.

As I walked into add this little bit, my wife said come and look at this, making its way across our dining room was a tiny mole snake, or thats what we think it was anyway.

I must be back in Africa!!!

Sorry if my blog posts are annoying some as they appear on the front page, very little hard core UAV and lots of off topic, but it should encourage some of the 270 other members to move me off the page ;-)

Gary Mortimer, now that the storm has passed.....

Settled back in South Africa after the glorious world cup rugby victory!! A storm is brewing outside so can't stay long!

I have been itching to get a shot of animals to start the process of getting software to spot them for me (grown ups will work that out)

It also crossed my mind whilst flying down to South Africa that a Zagi or some such flying wing would be a very robust platform to play with. Having never flown a powered flying wing I made up a balsa box for engine and battery and taped it onto my Xit flying wing.

My eldest Adam demonstrating here!!!

As you can tell another fine example of my engineering skills, still it worked it went like 5h1t off a shovel, a little two unstable for camera work. But if I could find a two metre span foam flying wing I think it would be a winner. My youngest Daniel demanded that it be turned back into a glider as he has most correctly spotted glider guiding is the finer form of model flying.

Next the Hobbico Superstar received the electric motor.

You all know what that looks like, so here we are before the off.

Anyhow that flew, but on adding my camera did'nt.

The aircraft did just not quite have the go at 4000' and plus 30C

Does anyone know a simple place for working out what a trainer type airframe might lift when temperature and density altitude have been taken into account?? I might just have to get out my E6B but have no idea what sort of thing a standard airframe would lift at ISA or how to work it out.

All rather annoying as the school that bounds the polo fields from which we fly has a small airfield, yes I said that right a small airfield. What would I have given to have an airfield at my school. Anyhow they have a few game animals, a couple of Zebra and some Blesbuck. If I can get some shots of them to my friend Lyndon Estes in the US then maybe his wizards can work out how to count them from video or stills.

I can use some ic powered airframes but I think that vibration will be an issue, maybe I will have just try that until the powers to be can be pursueded that I need a big electric glider ;-)

From inside the storm in Mooi River......

Bang

• Return to starting point when pilot looses the plane

• GPS input and parsing based on several NMEA codes
• Waypoint storage (one for now)
• SD card support
• Radio control receiver interface
• Servo control
• Video output of any GPS and microprocessor values
• As a separate unit, 2.4Ghz video downlinking.

• Video overlay on the downlink
• Google Earth Integration for setting routes (via KML file read/write)
• Pan/tilt/snap camera control integration