It is almost Christmas again. My flight back home is going to be on the 21st, 6am in the morning, 14,000 mileage back and forth.

Amos III is wired up with computer, GPS, and phidget. I droved it using joystick remotely through wireless network. Amos III already put a bunch of holes on the walls, so I put the motors back on 12V power source instead of 24V. Amazingly, Amos III is still capable of pushing tables with me sitting on it. Now I just have to wait for Stew to design sensor mounts for LIDAR, GPS Antenna, compass, as well as E-stop. After that, Amos III will be able to navigate on its own, guided by the software I wrote last year, erc v1.1, using a pure behavioral approach.

I also started to be involved in a multi-touch screen project. Basically, multi-touch screens allow multiple touch points to be recognized at the same time on the screen. Touch screens on laptops, cell phones, or other devices can generally recognize one or two touch points at the same time. Multi-touch screens can sense up to unlimited number of touch points, thus, amazing things like hand drawing, content organizing, resizing objects or even multiple users using the same screen can be done through multi-touch. Here is an amazing demo.

Although it is amazingly cool, most multi-touch screens are still very thick nowadays. The way most multi-touch screens works today is a combination of infrared lights and cameras. Basically, intensive infrared light is shined through the screen so that when an object comes close enough to the screen on the other side, infrared light is reflected back through the screen. A infrared camera will be able to pick up the reflection, clear enough to determine the position, shape and size of the object. By using infrared light source, visible lights generated by room lighting source or the screen itself will not interfere with the touch point sensing ability. On the other hand, infrared light can penetrate some surface, like a laptop screen, which allows the multi-touch technology to expand into a variety of devices. For example, Microsoft did a multi-touch screen using a projector projecting image onto a glass, and the user operating the screen on the other side of the glass. They also did some experiments around multi-touch laptop screen, where they put infrared light through the LCD from the back of the screen.

Our version of multi-touch screen works basically the same way. Since our club room has a glass wall on one side, we are utilizing the glass to do a multi-touch screen for club promotions. We put vellum on the glass and project image from inside the room. The users will be standing outside of the room in the hallway to operate the screen by hands. The project right now is at its initiate state, where we borrowed an old projector, bought 100 infrared LEDs, and have a webcam with a customized old film filter to filter out some of the visible lights and allow infrared to come through. By the way, cameras without good infrared filter can see infrared light. If you don’t believe me, try pointing your TV remote to your webcam and press down buttons. You will see the LED lights up on the remote through the webcam.

Another cool thing I forgot to mention is that we used the filtered webcam to observe the lasers from the LIDAR. The LIDAR has a spinning mirrors that redirects infrared laser to a 180 degree range and measures the distances from the reflecting objects at every 0.5 degree. Using the webcam, we saw a clear line being projected onto objects around the room by the LIDAR, which is really cool because normally you don’t see it. Later, we came up with this crazy idea about modifying our LIDAR strategy by puting a hot mirror controlled by a positioning servo right above the LIDAR lense to redirect where the lasers are pointing to. In this way, we can get around 100 degree wide 3D scan about our environment without moving the LIDAR itself. More research and experiments need to be done in this area before we can put it into the design of our IGVC robot this year, which by the way is very possibly going to be AMOS III.

BROWSE / IN TIMELINE
« Amos III is Alive!
» Multi-touch Software Development

BROWSE / IN SAME CATEGORY English
« Amos III is Alive!
» Multi-touch Software Development