Tuesday, August 31, 2010

3D freehand pen computer interface

Found on Tinkernology and Makezine.com: http://tinkernology.blogspot.com/2010/08/sensor-input.html   http://blog.makezine.com/archive/2010/08/3d_freehand_drawer.html

This is a cool device that has gotten some attention. It's a computer interface that takes in 3D points. You manipulate a pen connected to an arm with joints and the pen's position is calculated. The author of the video made it himself with a PICAXE controller*, but I'm pretty sure expensive units can be bought for computer modeling (CAD).

*Similar to the Ardino microcontrollers I've posted about.

Difficult quadrotor maneuvers

Found on BotJunkie.com: http://www.botjunkie.com/tag/quadrotor/

A quadrotor is a small, helicopter-like robot with 4 propellers. It's a project that seems to be a semi-classic robotics experiment for colleges and advanced techniques. Here's two colleges that have done some impressive work on quadrotors.

Aggressive quadrotor maneuvers
This is from the GRASP lab at the University of Pennsylvania. Note that the accurate movement is helped by the infrared cameras and lights mounted around the room.

Flying Inverted Pendulum
This is the Swiss Federal Institute of Technology Munich, which has balanced an inverted pendulum on one of their quadrotors. An inverted pendulum is an upside-down pendulum where the bottom, mounted part moves to keep the top, swinging part in balance. This is like when you balance something on your nose or in your hand, like a yardstick.

Zero: The Biography of a Dangerous Idea by Charles Seife


I recently read Zero: The Biography of a Dangerous Idea by Charles Seife. It's an interesting book that discusses the importance of zero and describes its history. You might have heard that back when counting and number systems were just being started, people didn't think of a number/digit that had the value of nothing. Somebody must have thought of it some time, yes, but it was much more complicated than that. Zero turns out to have been a very controversial concept that applies to historic worldviews and modern applications.

If you're in to math, I'd certainly suggest this book. But I agree with an Amazon.com reviewer that the author is a little too flowery and poetic sometimes.

Saturday, August 21, 2010

Mindstorms NXT Color Sorter

Found on Tinkernology: http://tinkernology.blogspot.com/2010/08/color-sorter.html
Robot maker's website: http://robotics.benedettelli.com/ (looks like there many other cool robots there)

A very very nice color sorter with an arm that picks up and places colored balls. A color sensor is on the ball rack. It uses RC servos in the arm, which is cool that they could integrate that with NXT. The ball containers are fairly clever too.

What's nice about this robot is that it is very fast and efficient. Other robots you might see (this could be anywhere) move slowly and ultra-methodically like they are running on a low-level computer. These are common among x-y plotters and unique walking or climbing robots. It is hundreds of times more impressive and efficient when things move faster and the robot multitasks movements. Call me arrogant if it really does take this level of processing and precision, but often in these cases it seems to an observer that the robot is not well developed in some way. At least let me say that if the video has to be sped up 8x to keep the person from falling asleep, there might be a problem.

Thursday, August 19, 2010

Sixth Sense computer/world interface

Website: http://www.pranavmistry.com/projects/sixthsense/

This has been recognized as a totally mind-blowing breakthrough idea by websites, magazines, and other technology people. Sixth Sense is a technology made and developed by Pranav Mistry at MIT, with help from his professor Pattie Maes.

It is a camera/projector combination that projects images on objects in the world and senses finger positions and gestures. Currently the fingers are sensed with colored tape or marker tips. This allows for interesting interaction with the digital and physical world. The best way to find out more is to watch the videos.

Demonstration of what Sixth Sense can do.

A more detailed video of Pranav Mistry and his work on interfaces, specifically building up to Sixth Sense.

Gesture computer interface with colored gloves

Found on Wired.com: http://www.wired.com/gadgetlab/2010/05/gloves-gesture-computing/

Sensing hands and gestures with cameras has not been done a lot, and this is a great example. This is from two researchers at MIT using colorful, stretchy gloves and a webcam. The specifically colored patches on the gloves are recognized by the computer and the hands' positions and locations can be found. The gloves are designed to work effectively in different lighting conditions and show the front and back of the hand.

Something innovative about this method is that the captured picture of the glove is compressed to a 40x40 pixel image and searched for a match in a database. The matched hand position is then used in the application. Since the position is not found by computing the relative position of the parts of the hand, this method can be very fast and efficient.

This video is very impressive:

A close up on the gloves:

Walking table: moves when you push it

Found on Makezine.com: http://blog.makezine.com/archive/2010/08/walking_table.html

Interesting idea, not totally practical of course. At first when I read the title, I thought it was robotic and moved on its own, which would also be a clever and funny thought.