Blimpbots Featured
Sam noticed that Dr. Duderstadt recently included a photo from the Blimpbots demonstration in his new report, "Engineering for a Changing World."
Check it out on page 61 of the PDF (the page numbered "50").
April 02, 2008
June 22, 2007
As seen by our computers
In this brief video, Patrick and I lead two unpowered blimps around the CSE atrium by means of fishing line. This is one of the test sequences used to test our from-scratch object tracking system. The markings that you can see on each blimp are placed completely automatically in realtime. The computers also know how large the object appears relative to several trained examples, and use this to formulate a 3D estimate for each blimp's position.
Use the full-screen button to see a bit more detail.
Alternate video formats: wmv, mpg.
Use the full-screen button to see a bit more detail.
Alternate video formats: wmv, mpg.
May 31, 2007
Up Up and Away!
So you want to make yourself a blimp. You've got a bunch of fancy electonical gizmos, some motors and propellers and a balloon full of helium. You're ready to go, right? Not so fast, hotshot. You're going to need something to tie all that stuff together. That's where the BlimpBot chassis comes in. Our blimp chassis had to be lightweight, stable, relatively aerodynamic, as well as accomodate batteries, motors, circuit boards and take a bump or two. Having access to the A&D school's laser cutter, we were able to work through a number of chassis designs in wood and acrylic. The acrylic designs ended up being heavier than the 1/8" model aircraft plywood we went with. We finally settled on a design that snapped together like a model airplane and was held together with wood glue. Mini zip ties held the battery and pcb board on. A dab of glue and some electrical tape wound around the motor housing secured the motors. The bumpers were made from carbon fiber strips from the hobby shop, bound with fishing line. The chassis was taped to the polyurethane blimp bags.
Below are the graphic files of the layout we used for the laser cutter. The idea was to get as much mileage as possible out of each 12" by 24" piece of plywood!
May 11, 2007
Demonstration snapshots
April 24, 2007
Give me the code!
We will be making much of our code available at the below URL. General project discussion will still take place on this blog.
April 23, 2007
Our finalized circuit board
Early in the project, I decided it would be a good idea to design an entirely new blimp control board, so that we would have a lot more control over what happens onboard each blimp. For projects like this, it is definitely good to see whether you can just purchase a canned solution, or if you will have to build it completley from scratch. Choosing either extreme is probably a bad choice.
With this PCB design and the accompanying firmware that runs on it, we ended up a little more on the "from scratch" end, but now hopefully others can leverage our work. We used expressPCB to produce our boards for a very reasonable charge, accompanied with fast delivery. Our final design is available for download. You'll need the (free) design software from expressPCB to open and manipulate the designs. An accompanying schematic is also available.
Now, in terms of features, this PCB has a quite a lot packed into a relatively small package:
- Onboard Microchip PIC18F1330 microcontroller, able to run at 32MHz with its internal oscillator. Beware of this inaccuracy in the currently-posted PDF manual!
- Serial communications with pins designed to mate with the Sparkfun BlueSMiRF. This allows the unit to operate remotely with very low power at a distance of 100 meters!
- Speed and direction control for 3 DC motors (400mA).
- Motor source voltage is separable from the main battery voltage -- so you can use different batteries to match your motors. If you don't need this, you just jump the main battery over.
- Two mutually-exclusive high-power outputs (400mA). We use these for two high-intensity LEDs.
- 0.01V-precise battery voltage sensing down to 3.0V.
- Pins designed to mate with an HMC6352 compass.
- Another pin set alternately compatible with this 3-axis accelerometer.
- Pin header for In-Circuit-Serial Programming with the Olimex PIC-MCP-USB programmer, which is compatible with the Microchip MPLAB.
- The whole thing weighs less that 15 grams populated, and measures just under 2.5" x 1.9".
Not bad for a first hack at a PCB, right?
April 21, 2007
All good things
On Friday night, before the demonstration, the blimpbots were dancing with new superbright red and blue LEDs....
The demonstration has concluded, and not without a bit of unintended excitement. (More on that soon, with photos and eventually video.) The project has concluded, but the conclusion is a soft one, and we will continue to broadcast blimpbot details here. Perhaps a flurry of such details as we wrap things up. All of our designs and much of our software will be available soon.
April 19, 2007
Come see Blimpbots
We are busy preparing for our public demonstration, which will be held this Saturday, April 21, starting between 4:00 and 5:00pm.
Our demonstration will be held in the Computer Science & Engineering Building's central atrium on North Campus. Just walk in and look up! Prior to our demonstration, the other GROCS projects will be presented in Design Lab 1 in the Duderstadt Center.
More info on that here.
April 04, 2007
Painting on plastic
Painting our new clear polyurethane blimp has been among the many things we've been working on in the past few weeks. We tested Krylon engine enamel and Krylon fusion spraypaint on plastic, and neither seemed to work particularly well. We ended up using fabric paint for the first blimp -- and you can see us applying it in the video below. Beyond this, there has been much progress on all other aspects, but we will save those details for forthcoming entries.
