Posted in General at 2:27 pm by Tijs

Hi there! Long time no see.. We have been rather busy (with Zeppy among other things), and we decided to focus on improving Zeppy, instead of updating the weblog.

What have we been up to, then?

New gondola
We’ve built a new home for Zeppy’s electronics. We built a gondola which contains the camera, motors, the gumstix computer, and the motor drivers. Underneath the gondola there is room for the battery. We use the lid of the butter-packaging as a dock on the zeppelin, so we can easily attach and detach the hardware from the balloon.

Zeppy Gondola

New motors
The motors that we borrowed from the toy-blimp just were not up to the task, since they were very noisy but not very powerful, and the rotors had a habit of coming loose in mid-flight.
So we bought three new EDP-20 motors with fitting rotors from a local shop. Since these motors are often used for model airplanes they are actually too powerful for our needs, but thanks to a little voltage regulation circuitry we can now easily configure the power of the motors.

Zeppy flies.. Beautifully!
New gondola, new motors, some programming, and.. Zeppy is airborne! - Even better: The steering is now very direct and responsive. For the first time, we can really fly our home-made blimp, and make it go wherever we want it to go.

Us looking at a flying zeppy.
Docking station
One of the motors is pointing downwards, and every time that zeppy lands or stands, he’s standing on this motor. To spare this motor, we’ve built a little ‘docking station’ for Zeppy. He looks very happy in his new home!

New balloon with logo
The university is enthusiastic, and we’ve been approached for some demonstrations in the near future, so we’ve decided to make a new better-looking balloon, with a logo on it.

We’ve got a new robot lab!
Our AI-department recently moved to a shiny new location, which houses a brand new robot-laboratory. Moving our delicate hardware and accessories was a bit problematic, but thankfully everything arrived safely. We had some funny looks riding our helium-filled canister to our new home!
The new robot-laboratory is large enough to merrily fly a zeppelin around. We can now fully appreciate our new motors, Zeppy can approach amazing speeds! The nasty sprinkler But, as it is with every change there are also downsides to our new playground, because all new buildings have to fulfill local fire-department regulations, meaning that they have to have sprinklers in every room.
Have you ever looked closely at a sprinkler? Have you seen the nasty sharp edges? They are sharp enough to cut right through an unsuspecting Zeppy.

We are still working on solving this problem, together with the building managers.

Sonar Sensor
In order to get a good measure of Zeppy’s height, we decided that we wanted to outfit Zeppy with a sonar sensor (Devantech SRF02). The sensor is amazingly light, weighing in on only 4.5 grams. We have already done all the soldering, and we are now working on reading the I2C data that the sonar supplies, which is somewhat tricky.

Basic sensor-motor coupling
We have created a lot of filters for the camera-images, which all output features. These features are based on motion detection and color-space information, for example.
Using the machine learning package WEKA, we extracted some basic rules as to when the zeppelin is flying to low to the ground. Applying these rules in the brain of Zeppy, will hopefully lead to a step closer to making Zeppy autonomous.

Zeppelin on other planets

And last but not least we made a nice movie of a zeppy roaming on an imaginary planet