Saturday, February 14, 2009

Add an icon to the page title!

For long I wanted to change the "B" icon thats displayed alogside the title of every blogger blog and have a unique icon for this blog. As usual, i approached Google for help and found one too! Now let me write how I changed the usual icon and used this "T" (For Techster, ofcourse!) icon. The works involved in this are

(i) Create an icon
(ii) Uploaded it to any web server
(iii) Use that for your blogger blog

Instead of going for any web server, I preffered to use blogger for storing my image. Since blogger doesn't allow you to upload a ".ico" file, I used the 'KIconEdit(Using KDE 3.5.4-10.fc6 Fedora-Core)' application in our college's browsing centre to create a simple icon and saved it as a png file. Then I created a new post(not for publishing) and uploaded this png image there. I copied the location of this image. Finally I added the following code inside the head section of the html code (Goto Layout ---> Edit html) of my blog page.

Save the edits and view your blog. You'l be getting your new icon for the title! :)

(i) You can directly use a jpeg picture. Just upload the pic, copy its lopcation and add the given line of code
(ii) I've used a picture of the code here since blogger will take it as a html tag if I type it directly.

Thursday, February 12, 2009

Satellites collide!

I was bored to the core and wanted to read something interesting. It was then I found a truly interesting article on the home page of Wikipedia. It was something about the "collision of satellites" - something that I have never heard of before! On February 10 this year, two satellites in orbit - Iridium 33 and Kosmos-2251 collided with each other directly while orbiting the earth. This direct collision was so severe that both were completely destroyed and more than 500 pieces of debris were tracked by U.S. Space Surveillance Network.

The Iridium 33 was launched on September 14, 1997 and was operational till the collision. The Kosmos-2251 was launched on June 16, 1993 and was retired before several years.

Hope that the debris produced by this collision won't pose a threat to the other spacecrafts and upcoming launches.
An artist's depiction!

Wednesday, February 4, 2009

The K! Project

Well, I'm back to take care of my log after quite a long period! Yeah, its not easy even to have proper meals when you are a part of the Project team of K '09. So, now that I'm back, without much bla bla bla, I'll directly jump into what I wanted to do all these days - post about our Kurukshetra Mega project.

This year's Mega project for Kurukshetra was A Strategic All-Terrain Robotic Platform. I was a part of the Mechanical Team comprising two - myself and Arun seashatri for the project. Santhosh, Vijayakumar and Karthikeyan took care of the electronics and programming part.

The objective
Our objective was to build a small robust unit that could navigate in rugged terrain and tackle small obstacles and most importantly do a surveillance work.

The Construction
We had certain things to keep in mind before starting the construction..

1) The most important thing - ALL TERRAIN NAVIGATION
2) Effective suspension - For enhanced camera feed from the vehicle
3) Sturdiness - our imported 130 RPM, 24 V motors may very well disintegrate the unit if it has a weak frame. Moreover it should hold 2 12 V UPS batteries each weighing more than 2.5 Kg.
4) An effective arm to pick small objects

Now, for the first concern - all terrain navigation - we had to decide on the type of wheels. We had a look at the trainer wheels in kids' cycles and thought that it would work out for us. Then we worked on the suspension. We fell upon the springs used in the gear box of ambassador cars. With the essential parts in hand, the design of the body was done easily. All that we had to do then was - go to the workshop; cut the metal (we used Mild Steel) ; put the things in place and bolt them! Wait, I forgot to tell about the arm! Even before deciding on the wheels, we finished the construction of the arm using 6mm thick Aluminium plates. Seshatri came up with an effective idea of a pulley system that could make the maximum use of low torque motors. It was very simple yet effective considering the limited options we had.

Finally after some two months(semester exams slowed us down), we were done with the chassis. It was time for a test run! The first test run gave us a BIG BIG BLOW!! Yeah, we totally forgot the "Buckling and twisting" nature of springs during the construction. The very high torque motors that we used made the springs twisted in different directions and caused big variations in the alignment of wheels. We had to use unconventional methods like placing bolts and clamps at appropriate places to control the twisting. But we couldn't stop the buckling. Only during the next test run, we realised that buckling - which is considered to be a bad aspect in suspension, actually helped us save the bot from the juggernaut of the motor!! The initial acceleration was immense that it could have toppled the bot without the spring that absorbed the force. Finally we added the gripper to the arm and mounted the arm. Santhosh turned up with better wheels for the bot - those wheels used in trolleys seen at airports. That type of wheel impressed all and we used that finally. (I'm simply sayin "we mounted the arm".. this is an understatement! we had to work for days and experienced sleepless night in doing these works!)

The Base Console
Atlast, after a lot of fine tuning and adjustments, the base console was ready. The base console was the most attractive part of the bot. The base being a computer, the console application displays
1) The camera feed
2) Parameters like system voltage, system current, motor supply voltage, remaining battery power etc..
3) The GPS module placed in the bot displays the coordinates of its current position and its velocity
4) Google map embedded in the application provides visuals of its location

Due to unexpected and shocking happenings like burning of TV tuner card in the computer, failure of the wireless transmitter of camera and so on just on the day before the date of display, we had to postpone the date of display by 2 days. After doing the necessary changes, we finally had a good show during the display. One thing which most people like about it was the unique suspension system ;-)..

Right now, I dont have the screenshots of the base console with me. So, I'll upload them later. as for now, I'll upload the only pic of the bot that I've got