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1. Israel has UAVs in the air 24/7, mostly on its borders. Unlike the piloted Air Force squadrons, where most flights are training, 90% of UAV missions are "operational", meaning that they're actually tracking targets and watching for bad guys.
2. They've been working to eliminate "flying" altogether. The UAVs take and land themselves, and "R/C" piloting skills, which were once prized, are now discouraged. It simplifies the training, lowers costs, and mimimizes human errors. Often the joysticks are linked only to the camera, and the aircraft is only guided by clicking on a map.
   
3. Another advantage of a small country (about the size of New Jersey): all the UAVs above hand-launch size are launched from Air Force bases like this one and communicate with the ground with direct radio links. No need for satellites. They can usually get an aerial camera on any spot along the boarder within three minutes. Aerial imagery is shared between Army and Air Force in real time, so there are few of the intramural battles the US has over chain of command and airspace control.

This post describes the beta version of BASIC Stamp autopilot code. As mentioned in my last post, the two main challenges in this project were dealing with the constraints of integer-only math and a severely restricted variable space (just 26 bytes!).

The first one I got around by treating fractional degrees as full degrees (since the UAV is never going to travel more than one full degree away from launch) and essentially treating them as integers. This was a little tricky, since I'm limited to word-length variables (with a max value of 65,535, which is essentially 4 and half digits of precision) and the GPS natively generates six and half digits of precision (360.9999 W/E). But I truncated the full degrees to just 1 and -1 from the current position, and that let me retain the full precision of the fractional degrees.

The second problem I got around by splitting the program up into five sub-programs (each one is allowed to reuse the variable space in RAM) and switching in real-time between them. I also used the Stamp chip's 121 bytes of "scratchpad" memory to store a lookup table of all the waypoints, and that's available to all the programs, although you can't manipulate the scratchpad memory directly without copying it into a variable.

The current program does three things:

1. It intercepts R/C receiver commands to the rudder, elevator and gear switch and translates them into computer commands, which drive the servos through a Parallax servo board or FT639 chip. When it detects that the gear switch has been thrown, it transfers control of the rudder and elevator to the autopilot program, and back again when the switch is returned to its manual position.
2. When under autopilot control, it reads GPS coordinates and headings and translates them into directional vectors to the next GPS waypoint. It uses those vectors to steer the rudder.
3. It also uses GPS altitude readings to do a crude sort of altitude hold. Because the GSP altitude data is so noisy, the autopilot averages over three readings and treats that as accurate +- 10 meters. It uses that data to adjust the elevator to try to keep the plane within a range of +- 10 meters of the original altitude at which it was put into autopilot mode.

The code has been tested on several different kinds of servo driver chips and GPS modules, as well as with GPS simulators, but not yet in the air. So consider it just instructional at this point. I'm sure there are some bugs, and a lot of settings that need to be tweaked. Also, we have not yet added camera controls and other more sophisticated in-air options, such as circle and hold (although these aren't hard to add, not that we've got the basic hardware interfaces working).

You can download the code at the following link. Load the first program (uav.bsp) and it will call the others at compile and download time.

The recommended hardware is a Basic Stamp BS2p on a dev board using the FT639 servo driver chip and a standard GPS module such as the EM406. Details on these hardware configurations can be found in the main post on this UAV. Other servo drivers, such as the Parallax board can be used, and the details on how to modify the code for them is in the comments of the code

• Basic Stamp autopilot code. [Latest version]

• Code for the Parallax servo board and Parallax GPS module is here.
• Similar code for the FT639 servo controller chip and Parallax GPS module is here.

We love GoogleMaps, but one of the problems with it is that you can't really add your own data to it. Sure, you can superimpose your imagery on a GoogleMaps layer, but it won't show unless people use a special URL. That's the reason for the creation of OpenAerialMap.

Pict'Earth's Jeff Johnson explains:

"OAM gives us a place to publish the imagery so that it easily reused. Basically the imagery that Google and MS Aggregate is not truly 'free' in the sense that it cannot be used in any useful sense outside of their programs without an overbearing license. Its kind of like Navteq or Teleatlas data. It may be freely available, but its not really free. So then, the goal of OAM is to provide a place where people like us (doing DIY stuff) can publish our imagery in a central place, but also a place for governments and other organizations that pay for imagery to get help publishing their data into the public space in an open/free way."

O'Reilly's Brady Forrest has great post that explans more here. (He also mentioned that I'm going to be giving a DIYDrones presentation at ETech on March 3-4 in San Diego. More on that later.)

You can see one example of one pass I took of the Alameda Naval Air Station runway that was orthrectified and stitched by Pict'Earth and is now part of the standard OAM map at that lat-lon (our imagery circled in the screen shot above).

(credits: Christopher Schmidt set up OpenAerialMap and the servers are hosted by Telascience, SDSC and bandwidth comes from CalIT)

Hi my name is Rob Swynnerton, i run a small company, www.flyingwings.co.uk. We manufacture a range of EPP models, wings etc. We also make parts for UAV contractors and this has sparked my imagination, what would be a great UAV test platform ? What size, payload capacity, what would be better than a commercially available model ie twin jet etc. Designs that inspire me are the Desert Hawk and the Raven, small micro UAV's with a wingspan of around 48-60" and payload of 1-1.5kg. Any help would be appreciated.

ps.... big up to Gary Mortimer for steering me here.

Rob

From an email that Rob just sent... Now I'm sure we all have ideas for what we would like in an airframe.

If you put it here I'll make sure he reads this thread.

The desert hawk is epp, and so are others being developed. We are producing airframes

for a major UK military contractor, its gone UAV crazy over here with a massive dedicated centre being built here in Bristol.

It would be good fun to create a package for amateur developers .

If you have a spec you would like, then let me know.

Regards Rob

Tarbert says it's possible that some regulation recommendations could be produced by July 2008, although he calls that "a big, big if." Even then, a Notice of Proposed Rulemaking wouldn't "hit the street" until a year later, and a public comment period of 90 days would follow after that, so any regulations likely wouldn't come into play until the middle of 2010.

One problem is that there's no definition yet for what a small unmanned aerial system is. MITRE Corp. has taken a stab at defining it for the FAA, and Charlotte Laqui, the UAS project team leader for the company, also spoke at the Wednesday meeting.

Stressing that the definition is just a "starting point," and certainly hasn't been accepted by the FAA, Laqui says MITRE has roughly defined possible operations for two classes of small vehicles.

One would have a maximum weight of four pounds, a flight ceiling of 400 feet above ground level and could fly in all classes of airspace. Such vehicles could fly over even heavily populated areas without posing a big risk to people on the ground or other vehicles in the air. Another class of vehicle could weigh up to 35 pounds, fly up to 1,200 feet above ground level only in Class G, or uncontrolled, airspace. Those vehicles would pose an acceptable risk in more lightly populated areas.

Vehicles could not operate within three miles of a chartered airport and would have to be kept within sight of the operators, she says.

Whilst flicking through the pages of a magazine, I came across....

The only down side for South Africa and in particular up here in the mountains is the size, probably can't lift a camera as well with a high density altitude.

I send an email off to Flying Wings asking for a bigger one and Robert Swynnerton very quickly replied that they were building one for our very purpose that would be available soon.

Called the Observer and I quote....

The Observer will be modular so you can have a conventional tail anddifferent payload configs, as you wish. It will look similar to the DessertHawk 1, seeRobert Swynnerton

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?)