Chris Anderson's Posts

Minimum Blimp V2 update

Posted by Chris Anderson on March 19, 2008 at 6:00am

As mentioned before, for the second version of our Minimum Blimp Jordi and I decided to mod a RC toy blimp on the grounds that it will be cheaper and more robust than trying to build the whole mechanical assembly ourselves (the aim is to have a fully programmable and hackable blimp UAV kit for less than $100). Jordi started with $15 toy (gondola shown above), ripped out the RC electronics and built his own Arduinio board, IR sensor package and added a Ping))) sensor for altitude hold. Here are a few shots of the first version (please forgive the protoboard disasters--we'll neaten it up for the next rev!)

Underside of the blimp gondola, showing custom IR sensors for navigation and Ping))) ultrasonic sensor for altitude hold. (enlarge to check out the DIYDrones branding on the IR board!)

Inside of the blimp gondola, showing the custom Arduino board. This Toy blimp just got a major brain transplant! We'll be showing a more polished version of this blimp at the FIRST Robotics National Championship in Atlanta, April 17-19.

3D Robotics

What does "Open Source Hardware" mean?

Posted by Chris Anderson on March 18, 2008 at 2:00pm

Here at DIY Drones, we adhere to open source principles wherever possible. That means we aim to share (that means post it, not make people ask for it) code, schematics, PCB files, parts lists, instructions, and algorithms for every project featured here. In practice, that's not always possible (not all project have PCB files; not all projects need schematics), but it's our philosophy. Is that "open source"? In spirit, yes. But in letter, it's more complicated, because hardware is more complicated than software. We can't GPL a parts list, and the license that we do use for this site, a Creative Commons "Attribution" license (use/modify what you want, but give credit), doesn't have the same viral characteristics of the GPL in the sense that people who use our intellectual property are free to keep closed their "derivative work" if they want. This is all a bit messy and complicated, but fortunately Phil Torrone of Make Magazine gave a great talk on Open Source Hardware at Etech that helps explains all this, and it's now available.

3D Robotics

A clever approach to indoor beacons: ultrasound + IR = GPS

Posted by Chris Anderson on March 18, 2008 at 5:13am

A Luxembourg-based team has come up with a really clever indoor navigation system that combines ultrasonic beacons with IR to achieve absolute position ("synthetic GPS"), much like the NorthStar system we use but entirely DIY. As they describe it: "The infrared flash of a single beacon arrives instantaneously at the robot that is equipped with a combined infrared/ultrasonic receiver. But the ultrasonic signal only arrives with a certain delay, due to the "slow" sound velocity, in comparison to the speed of light. The receiver is able to measure the time lag between both signals and deduce the distance between the robot and the beacon." Features include: # participation of up to 7 beacons that may be placed at strategically interesting places # the beacons send out strong IR and ultrasonic signals that don't require reflectors on the receiver side # like RF-beacons, these beacons transmit their identification number, making localization easy # always one beacon acts as the master beacon, sending out a synchronization message to all other slave beacons The project is entirely open source and is in the proto-board stage (see below). It was designed to work with LEGO Mindstorms NXT and as such uses I2C output. But that, of course, is also readable by any microcontroller, so it could work as well with Arduino or Basic Stamp. Looks like a great opportunity for one of our PCB whiz's to make a small and light version for blimps!

3D Robotics

BoingBoing TV features DIY Drones!

Posted by Chris Anderson on March 13, 2008 at 9:26am

Our Minimum Blimp demo at ETech is the focus of today's Boing Boing TV. Learn how Jordi and Chris met and watch Jordi get subtitled! (Note: Some of the imagery is taken from elsewhere on this site and other presentations I've made and doesn't actually come from the Minimum Blimp or any blimp for that matter. It's just there for flavor...)

3D Robotics

Minimum Blimp UAV (Version 1) schematic and code

Posted by Chris Anderson on March 11, 2008 at 9:30pm

For those who want to reproduce what we did with the Minimum Blimp, the schematic is above. The Arduino code is here. We're now moving on the Minimum Blimp Version 2, which will be based on a custom PCB. Rather than use the flimsy and expensive BlubberBot kit as the starting point, we're probably going to mod a $15 RC toy blimp. We just rip out the RC unit, put in our Arduino processor board and sensors, and presto, instant UAV! And under $100...

3D Robotics

Regulatory FAQ

Posted by Chris Anderson on March 9, 2008 at 8:30pm

[These are Frequently Asked Questions about the current state of UAV regulation in the US. Regulations elsewhere are different, but here is a similar post giving the rules for Canada.]

Q: Are UAVs legal in the United States?

A: Under certain conditions, they are. There are two ways to legally fly Unmanned Aerial Vehicles in the "National Airspace", which is to say all but certain restricted areas: 1) Get a Certificate of Authorization (COA) from the FAA, a process that can take months or more. 2) Fly under exemptions granted to non-commercial ("recreational") flyers who adhere to certain restrictions. More detail is here.

Q) What are those restrictions for non-commercial UAVs flying without a COA?

A: You MUST do the following: 1) Stay below 400ft. 2) Maintain a "pilot in control", which is to say that you must always be able to take manual control and fly the aircraft out of danger (in general, that means maintaining line-of-sight contact with the aircraft). 3) Stay away from built-up areas. More detail is here.

Q) Who can apply for a COA?

A: Typically only government agencies (Law enforcement, Civil government, etc). This is not an option for a private individual.

Q) I've heard that the FAA doesn't allow unmanned aircraft with cameras and/or GPS. True?

A) No. Commercial use of aircraft with cameras is regulated as above, but aircraft flying under the recreational exemption may use cameras and GPS.

Q) What countries have more relaxed UAV regulations?

A) Australia and New Zealand are famously progressive in their UAV policies. Other countries, such as Mexico, have been know to be relatively friendly, too.

Q) What are the prospects for FAA regulations that allow amateur UAVs more freedom?

A) There is currently a rulemaking proceeding that aims to improve the regulations on UAVs. It will take a while; indeed, you shouldn't hope for anything before 2010-2012. There may be a special category for UAVs under 4 pounds, which may be more lightly regulated. But then again there may not. It's all up in the air, so to speak, and the forces that oppose amateur or commercial UAVs in the National Airspace are many and powerful. Speak up!

Q) What about universities and other students. Any exemptions for them?

A) Not automatically. But they may be able to get COAs more easily if they are federally funded and go through that agency.

Q) What if I break the rules?

A) Well, for starters, we don't want to hear about it here! We realize, of course, that people break the rules all the time on the assumption that if they use good judgment and stay away from built-up areas, they won't be caught. That may indeed be the case, but it will only take one cowboy flying a UAV into an airport landing zone and endangering civil aviation to set our hobby back by decades. So please don't do it! (Plus you could go to jail)

Q) Okay, I'm obeying all the rules. Are there any other guidelines for safe and responsible UAV operations?

A) Yes. RCAPA (the RC aerial photography association) has some excellent guidelines that are a great place to start.

3D Robotics

PicoPilot software updated

Posted by Chris Anderson on March 9, 2008 at 7:47pm

The good folks at UNAV have been listening to our complaints about the way their software handles communications errors if you don't have your Com ports set up just right when running the software (it basically barfed up a cascade of mystifying error messages, with no indication of what was really wrong and what to do about it). They've now created a new version of the main program (the waypoint editor) that handles Com port problems much better (see screenshot). You can download the new version here. (It will only work if you've already installed all the other software that comes with the PicoPilot). Thanks, UNAV!

3D Robotics

Testing the real world range of the Pololu IR transcievers

Posted by Chris Anderson on March 8, 2008 at 8:00pm

As you know, we've had a lot of trouble with the short range of our Pololu IR transceivers that we use with our Blimp UAV. They're rated at up to 20 feet, but we can't seem to get more than 10 feet (and usually more like 5) in real world conditions, with the usual amount of IR noise and the two transceivers not being on the same horizontal plane. I know that the power of the transmitting LEDs should be roughly proportional to input voltage (they're rated from 6-16 volts), so I thought I'd test them at different voltages. Here are the results:

Note that this is on the same horizontal plane. If you're not on the same plane, as we usually aren't, you need to cut those figures in half. So basically it doesn't look like we're ever going to get more than about 7 ft of range reliably. That means it's time to make our own custom IR transceivers with high-power LEDs and a dome array (to handle 3D positions). We'll save weight and money in the process, so this is well worth doing.

3D Robotics

Failsafe board now cheaper, better

Posted by Chris Anderson on March 6, 2008 at 7:22am

The Failsafe board (known as a "RxMux", or Receiver Multiplexer) that I wrote about before (and here) is now available for $20 less and with the connectors that I complained were missing in the original and hard to find. It's now $79 and the connectors are $10. Get it here and the connectors here.

3D Robotics

ETech BlimpBot demo report: Success!

Posted by Chris Anderson on March 5, 2008 at 4:00pm

Well, that went better. After last week's disaster, Jordi and I worked hard to make the Etech demo of the Minimum Blimp UAV go smoothly. It was almost a full hour, and the room was a bit smaller, so we were optimistic. But we weren't counting on optimism alone: Jordi had done a lot of work on the blimp since TED to help it handle air currents better, including:

Using the voltage regulators on the Pololu Motor Driver boards rather than a stand-alone voltage regulator.
Adding a separate battery for the motors so high current drains and voltage drops don't risk crashing our Arduino. (This is a short term hack while we get our power management properly fixed and switch to LiPos)
Upgrading the vertical motor to a low voltage N20, which has a better power to thrust ratio than the motor we'd been using
Tweaking the code to give full thrust when needed, which is allowed by the better power management
Other tweaks in the software to adapt to the inertial momentum and laggy physics of a blimp in a moving fluid
The result: success! The range of the IR transceiver is still less than ten feet in a noisy environment like a conference hall, but it nicely follows you around if you hold the beacon and walk around the room and otherwise does what it's supposed to do. Presentation went great, full room, people seemed to love it and video crews interviewed us afterwards. (Links to coverage when they go live)
Next: Minimum Blimp UAV 2.0 with a custom PCB, single LiPo and integrated motor driver chips. And then a kit you can buy and build for less than $100. Stay tuned! [Photo of Jordi credit: Phil Windley]

3D Robotics

Great primer on accelerometers and basic triginometry

Posted by Chris Anderson on March 4, 2008 at 7:42am

I'll be the first to admit it: I had to relearn a lot of trig that I was last taught in 7th grade when I started work on autopilots. Now Freescale, who makes accelerometers, has come out with a really easy to understand primer on the math of tilt sensing that make it all wonderfully simple. Well worth checking out.

3D Robotics

TED Report: Foiled by Air Conditioning!

Posted by Chris Anderson on March 1, 2008 at 7:00am

Yesterday Jordi and his wife drove up with the BlimpBot to Monterey, where I was attending the TED conference, so I could demo it. This was a pretty high-stakes demo, since not only would there be 2,000 of the most influential people in the technology, entertainment and design (TED) worlds watching, but they included Al Gore in the FRONT ROW, Google's Sergey Brin and Larry Page and movie stars such as John Cusack and Cameron Diaz. The bot worked great in the hotel room, and then we took it the the auditorium during a break to test it on the main stage. Yikes. We were getting IR interference from everything, from LCD screens to the bright stage lights, and our reception range dropped to something around three feet. Even worse, the air currents were overcoming the blimp's ability to fight them. So we gave up on the idea of a fixed IR beacon on the ground, and I decided to hold it in my hand to keep it near the blimp. Even then, the motors couldn't fight the currents well enough. So we rushed back to our staging area (my hotel room) and Jordi updated the firmware to give more power to the motors even at the cost of battery life (this demo only had to run three minutes) . We tested it again in the hotel room, it worked fine, and then it was time to go. When we got to auditorium and waited in the wings to go on, it was clear that something bad had happened in the firmware update. The vertical motor wasn't coming on at all sometimes and it wasn't clear why. Then Jordi realized that in changing the power settings, he'd also changed the timing of the loops, and we weren't resetting the motor controllers at the right time, which meant that the chance of them working when needed was random (and low). We'd just been lucky in the hotel room, but clearly weren't now. Still, I crossed my fingers and went on, carrying the blimp. Disaster! It turns out that one big thing had changed since our test run in the auditorium: 600 people had arrived. All that body heat had raised the temperature of the room, kicking in the air conditioning, which came out of huge ducts right over the stage. Basically I was under a raging waterfall of cold air, and the poor blimp sank right to the floor, its little vertical thruster completely overcome.

Lesson 1: Little blimps need still air
Lesson 2: If you can't find still air, you need WAY more powerful thrusters (which means more battery power, which means more weight, which probably means a bigger blimp)
Lesson 3: Don't update your firmware five minutes before you're going to fly an autonomous robot ten feet away from a former Vice President of the United States.
Lesson 4: Hey, it's a tech demo on stage, and they *always* go wrong--don't let it throw you. So I didn't. I just stood there holding the blimp, as you can see in the picture above, and went on with my talk and slides as planned. Points made, time limit met, applause gained. I looked a bit awkward, I'm sure (although hopefully not always as unhappy as I look above), but at least I got the sympathy vote! Now on to San Diego for Etech on Tuesday, where we get to do it again for an hour in front of the smartest geeks in the world. So much for the sympathy vote ;-) Jordi's hard at work fixing the firmware problems, so fingers crossed...

[Photo credit: Red Maxwell]

3D Robotics

Getting ready to debut the Minimum Blimp UAV at TED

Posted by Chris Anderson on February 28, 2008 at 12:30pm

Tomorrow Jordi and I will give everyone at the TED conference in Monterey the first public preview of the Minimum Blimp UAV. I did the design and Jordi did all the work! Jordi has more detail in his post (apologies for the repetition!), but basically we took a BlubberBot, kept the envelope, two motors and the plastic motor mounts, and threw everything else out. We added IR position sensors, ultrasonic altitude sensors, an Arduino "Lilypad" and a third motor for vertical control. Our autopilot, sensor and thrust package looks like this:

And it works! Here's a video of it circling a ground-based beacon and maintaining altitude. Extending that to full-room autonomy is simply a matter of adding beacons as waypoint markers.

3D Robotics

Interview: UNAV's Dave Perry on the PicoPilot autopilot

Posted by Chris Anderson on February 26, 2008 at 10:30pm

If you want an autopilot for less than $1,000 today you only have two choices: Do it Yourself or buy a PicoPilot (Dean Goedde's AttoPilot isn't out yet). The PicoPilot, which has been out since 2003, is small, light, and simple, and comes in varieties that range from simple one-axis rudder control to barometrically controlled elevator and/or throttle (prices ranges from $500 to $800). We have a couple of them, and we've found that once you've gotten over the slightly tricky setup, they're reliable and easy to use. I thought I'd continue this interview series by talking with Dave Perry, the owner and President of UNAV. Q: First, a little about you. What's your own background and how did you get into this? A: I'm the owner and president of UNAV, LLC. My background has been in aerospace, working as an electrical engineer in the Seattle area . Positions held include, hardware engineer, software engineer and engineering manager. My credentials include a BSEE and a Commercial pilots license. My almost 40 years of experience in electronics includes both hardware and software design, specializing in embedded projects. I've also flown Cessna's and other light planes in Alaska and have been active in the RC hobby since 1973. Q: What's the history of UNAV? A: I got started in the UAV business back in 1990 when a RC buddy asked me to help him with the electronics on a government contract for some large RC helicopters ( UAVs ). It didn't take long before the customer was asking for custom electronics. In those early days, I was doing business as "PDC", but the company name was changed to UNAV, LLC in 2000. Today we operate as a virtual company with six people on the team. Richard and Mark are my old RC buddies and Mark is our technician and tech. support guy. Jodi and Charles handle manufacturing and Brad is our business consultant. Q: Although we know your professional-quality 3500 product line is excellent and the recent price reduction make it very attractive, we're focused on the sub-$1,000 space, and that means the PicoPilot line. It was first released in 2003, and although it was revolutionary in the price/performance at the time, it's now starting to show its age, especially on the software side. What's next for this line? A: PICOPILOT was specifically designed to be simple and easy to use with a low price-- not all UAV customers have the skills necessary to deal with a more sophisticated system. One of the most common complaints we hear from former CloudCap and Micropilot customers ($5K to $10K autopilots) is that they are are just too complicated ! We've sold many PICOPILOTs to former "high-end" users. UNAV does offer a much more sophisticated autopilot, the 3500FW with a feature set comparable to the ($5K to $10K) autopilots out there. Some notable exceptions: a lot of time was spent making the 3500 system user-friendly and it's priced at $2500.

The first PICOPILOT was sold in October 2003. PICOPILOT has become the benchmark for low cost autopilots because it's been around a long time and developed a good reputation. Like most software based products, the design has evolved over time, in-fact my software notes show that we are currently shipping firmware revision 23 for the NAV2. The history of the PICOPILOT firmware can be traced back even farther to the PDC10 which was first released in March 2000. We've sold about 250 PICOPILOTs to date.

Even the $500 PICOPILOT-N provides a lot of capability. Last fall we demonstrated our EasyLander electric motor-glider (24oz gross) flying a 17 mile route over Baker Lake in the North Cascade mountains. Our chase boat could barely keep up with the little plane. I don't think PICOPILOT is starting showing its age, we've successfully tested installation on VISTA and a RS232 port can be added to any computer that doesn't have one. UNAV has an on-going R&D program and we are currently developing new products, including in the sub-$1,000 space. Watch for announcements on our website. Q: What do you think of Dean Goedde's thermopile approach, as opposed to your own IMU technology? A: PICOPILOT does not use an IMU or IR sensors, it uses our proprietary rate control system . I know most low cost autopilots use the FMA Co-Pilot for attitude control but anyone that's used it knows it has limitations. Unlike the CO-PILOT, the PICOPILOT attitude control is not affected by terrain, weather or surface water. A couple times now we've unintentionally demonstrated PICOPILOT's ability to control the plane and navigate when it flew into a cloud ! Q: Recent export control regs have made it impossible for you to sell outside the US. What are the prospects for export approval for your autopilots, and in the meantime, what do you suggest that non-US customers buy instead? (Obviously, our suggestion is that they DIY, but that's not right for everyone ;-) A: I'll leave the interpretation of US export regulations to the lawyers but you can read them for yourself by looking up 9A012 on the EAR or go to our website and click the"US Export regulations" link . I can tell you that we have successfully obtained export licenses for several of our customers in Europe and have shipped PICOPILOTs to them. Your readers should be aware that the export regulations make no distinction between hobby ( DIY ) or commercial UAV components and any air-vehicle with an autopilot is defined as a UAV.

3D Robotics

Lego GPS Autopilot code now less buggy!

Posted by Chris Anderson on February 24, 2008 at 11:30pm

For those of you interested in building a Lego Mindstorms UAV, two updates: 1) I've improved the RobotC code for the Bluetooth GPS version, in which I caught a lot of bugs. If you were having trouble with it before, download it again and see how it works. 2) At an event in April (can't say more than that), I'll be unveiling the next version of the Lego Mindstorms UAV, which will be a full IMU-driven autopilot. I can't say more about it now, but you'll be blown away. It's not a toy anymore ;-)

3D Robotics

New autopilot/IMU board from SparkFun

Posted by Chris Anderson on February 18, 2008 at 3:00pm

Some of you may have noticed that for quite a while SparkFun has been listing a "UAV Development Platform - ET312 + IMU" that's always been out of stock. I backordered one out of curiosity last year, and pretty much forgot about it. Then, last week, SparkFun called and said that they'd "finally got it working" and it was now available for backorder customers. Did I want one? Sure! It showed up today and it's going to take me some time to figure it out properly, but here are some first observations:

It's a "development platform", not a fully-featured working autopilot. Although there is firmware available for it, it's designed to be a standard hardware package around which you can develop your own autopilot code.
The firmware comes pre-loaded, and works pretty much as advertised. I tested it on the ground, so it was hard to tell how well it actually stabilizes a plane, but the elevator seemed to respond properly to tilting. The rudder didn't, but that was probably because it was trying to turn the "plane" to a destination and I wasn't playing along ;-)
That firmware is written in assembly, so good luck to you! It seems to do pretty much the basics of what you'd want an autopilot to do (and I mean basics--there's no provision for waypoints, and it's just a "fly home" autopilot at the moment), but if you want to tweak it you'll have to do learn PIC assembly (not super hard, but still: what's wrong with C?!)
It includes a 4-degree-of-freedom IMU: two gyros and one two-axis accelerometer.
As the two-axis configuration suggests, it's designed to control just two channels: elevator and rudder. A third channel is used to turn it on and off.
It's got a good SiRF III GPS module on board, although you'll need to add your own antenna through the included SMA connector.
At $299, it's not cheap. But when you consider that a simple set of accelerometers and gyros will set you back $109, the addition of GPS and a PIC processor, all nicely integrated on a board, is probably worth it. But it still seems about $100 overpriced to me.
You need some additional hardware to work with it: the main thing is an ICD2 interface to program the onboard PIC chip and for debugging. That will set you back another $120.
The documentation looks excellent, with a lot of theory on control and aerodynamics as well as a lot of help on PIC assembly language and development suggestions for the platform.
Bottom line: this looks like a good, albeit expensive, way to learn about IMU-based autopilots. It's not really an autopilot itself yet, but could be made into a relatively low-featured one pretty easily. I think it's accurately described as a "development platform", so if you're in the market for that and can afford a $300 lesson, I can recommend it as a unique and well-made way to get started.

3D Robotics

Minimum Blimp UAV bench testing

Posted by Chris Anderson on February 18, 2008 at 1:30pm

Jordi and I have been hard at work on the Minimum Blimp UAV and things are coming together nicely. Here are some videos: First, a test of the Ping))) sensor that we're using for altitude hold. Don't you love the tray-table simulation platform? ;-) The Ping))) sensors are strapped to the far end of the table.

Next, a test of the location-spotting IR tranceivers. In this test we've done a few interesting things. First, you'll note the LEDs turn off for part of the trial. That's because the onboard IR tranceiver doesn't need to have its LEDs on (which consume a lot of power) because it's only receiving data on the position of the beacon transceiver. (The ground-based beacon doesn't need to know where the blimp is) So we take a reading every second, then disable the board for the rest of the second--it's easy to do in software and the board comes back in 75ms each time. Like this: -Set the Enable pin to High (turn on the beacon) -Wait 75 milli seconds to give time for wake up -Read and store the 4 inputs (depending on how noisy the data is in the real world, we make take a dozen readings at 200Hz here and average them to create a direction vector) -Turn off the beacon (Enable pin low) -Process the data, and return the result for navigation... The second thing we've done is boost the voltage going into the ground-based transceiver to extend its range. We got 10 feet at 5v, but the boards can take up to 16v. We'll do a proper test over the next few days, but I'm hoping to get at least 20ft with higher voltage. And since that's 20ft in each direction, it potentially gives us a working blimp range of 40ft, centered around the beacon.

3D Robotics

Demo of a failsafe board for the Basic Stamp autopilot

Posted by Chris Anderson on February 18, 2008 at 11:30am

In an earlier post, I discussed the importance of having a redundant failsafe board so you can regain control in the advent (likelyhood!) of an autopilot failure. Basically, what that board does is sits in-between your autopilot, RC receiver and servos. You switch it between receiver and autopilot with a spare channels on your transmitter. If your autopilot fails, even if it loses all power, the failsafe board, which is independently powered, will allow you to switch control back to the RC system. Here's a quick tutorial on the board we chose, an RxMux from Reactive Technologies:. You'll need to do two bits of soldering first. The board doesn't come with connectors, so you've got to order those. It's a little funky, but the way to do that is to "build a part" at Smatec. The connectors you need are Samtec TSW-108-25-G-T-RA, and you just enter in the right numbers or letters in each data field, and it then confirms that this is a valid part and lets you order a sample for free! They sent me three of these right-angle connectors, which was just what I needed. Thanks Samtec! Once you get them you solder them on to the RxMux. The second bit of soldering is that you've got to make a couple of female-to-female Y-cables. Simply take three of these cables and cut them in half, then resolder the wires, two connectors on one side, one on the other, with heatshrink tubing at each junction. Then just plug it all together. The channels that don't go through your autopilot can go straight to Input A on the RxMux. The ones that do go through your autopilot will use the Y connectors, with one lead going to the RxMux and the other to the autopilot. And all the servo-out leads from your autopilot go to Input B on the RxMux. It's a lot of wires, but it's actually pretty straightforward. There's no configuration required of the RxMux--whatever RC channel you connect to the Channel 8 input of the RxMux's Input A is the switching channel, and it just transfers control of the servos from Input A to Input B and back again as desired. Here's a video of it at work:

3D Robotics

GPS simulation with Microsoft Flight Simulator 2004

Posted by Chris Anderson on February 17, 2008 at 9:36pm

We love FlightGear and all that it stands for, but the truth is that it's a bit complicated for beginners. For the rest of us, there's the old stand-by, Microsoft Flight simulator. There's a free plug-in for MS Flight Simulator 2004 called GPSOut that simply outputs GPS of the current flight to the serial port of your choosing, with whatever NMEA sentences you want. If you've got FS 2004, download that, copy the dll and ini files to your Flight Simulator modules folder and edit the following lines in the GSPout.ini file so that they read like this: Sentences=RMC,GGA [add any others you want] Port=COM2 [change to whatever port you're using for your serial connection that substitutes for your GPS] Speed=4800 There's no sign of the plug-in in the FS program when it's running, but if you've copied it to the right directory, it should be silently outputting the GPS in the background while you're flying. So fly to the area where you'll be testing your real UAV and you should see the correct GPS data streaming into your Basic Stamp autopilot. Here's a video of this working (that's me and my ten-year-old):

3D Robotics

How college Blimp UAV contests work

Posted by Chris Anderson on February 16, 2008 at 10:00am

The main existing US Blimp UAV competition is the Indoor Aerial Robot Competition (IARC) held every year since 2005 at Drexel University in Phladelphia. The contest is designed mostly as an exercise in remote control, both human and computer. The blimps appear to be all RC, with wireless cameras pointing down. The robotics part is either an image processing and control task, where the ground-based computer analyzes the video and transmits commands to the blimp via a trainer cord to a standard RC transmitter, or one in which a human operator does the same thing (looking only at the video stream). Examples of the computer-driven tasks are line following and fighting gusts of wind, while the human-driven tasks include following a maze and spotting objects in a certain order. The basic platform is a $850 52" envelope with three motors, servo vectoring (meaning the motors are on a shaft that tilts them up or down), and no onboard intelligence, either processing or sensors (it's just RC, with a wireless camera). The contest description includes the possibility that teams could add ultrasonic sensors or gauge speed and direction with optical flow calculations from the camera, and some have done that with ultrasonic and IR sensors, but all the data is sent to the ground computers, processed there, and turned into RC commands back to the blimp. Here's a paper that describes how one team's blimp works. The main difference between this approach and the one we're pursuing with our Minimum and Maximum Blimp UAVs is that we're entirely focused on onboard intelligence and sensing. Our blimps have two-way wireless links, but not conventional RC ones, and they're not designed for manual control. At the moment, we're making the autonomous navigation job easier with ground-based beacons, but the aim is to do away with those eventually and navigate like our outdoor UAVs do, entirely on their own. Here's a video from last year's competition, which was held in April (presumably this year's will be announced soon--I've emailed for more info):