MICRMOUSE : Micromouse is an event where small robot mice solve a 16x16 maze. It began in late 1970s, although there is some indication of events in 1950. Events are held worldwide, and are most popular in the UK, US, Japan, Singapore and South Korea. In India, the contest is being held in IIT-Bombay during its technical festival for past few years. Our MICROMOUSE
And this chart was prepared by me, though I like drawing and painting and stuff... but again, advertising is not my cup of tea.
We worked for whole of Feb and March to make our mouse move. The problem with the one which we took to Mumbai was that it was too heavy to lit itself, so, we decided to send it to VLCC for the weight los program. As a result, we got a new chasis, fabricated wih aluminium /* instead of cheed wood, which we used earlier */, at my room. Wings were fabricated with bakelite /* blank PCB board :P */. Also, we reduced the number of sensors to three on each side wing, from four. One of the biggest trouble, which stil doesnot have a satisfactory solution was the castor wheel. We couldnot find a light weight castor wheel. And finally what we put is a small trailing wheel, steered by a DC motor. Though we are not using proper steernig, we are just having on the spot turn. So, the steering wheel is either parallel or perpendicular to the two control wheels.
If I have to describe it, it is like, on the input side, we have eight IR sensors, two on the front wing, three on each side wing. The advantage of such positioning of sensor is that as the sensor are downward facing, they donot hae trouble with ambient light, as can be the case with many IR sensors. Apart from that, this design is easiest to work on :P. The two front sensor are to detect the front walls and to avoid head-on collision with a wall in case of some mishappening. The three sensors on each wing, the centre one helps to detect if there is a wall in a particular grid or not while the other two on each wing helps in maintaining a straight path while moving. That is the input part.
Now, for processing, we used Philips P89C51RD2 microcontroller, with 64K coding area and 2K RAM. Thoguh generally, people dont prefer Philips microcontroller, Atmel and PIC are the big names in the field, but we had to go for this one as we found programmer for this one only. A programmer is a hardware device which helps in gettng the code from the computer to the microcontroller.
On the output side, we had two stepper motor /* this pair we got from Lamington, Mumbai */ which are diretly attached to the two wheels. Stpper motors give better accuracy, though they take up more current as compared to geared DC motor, but stepper motors are fairly simple to use, and hey, this was our first hand in robotics, so we played safe by going with this one. Aprat from that, we had a DC motor aso to steer, which I had mentioned earlier.
The electronis included obviusosly the controller P89C51RD2. On the input side, we directly took the output of IR sensors to muC. These sensors ON2509, are proximity sensors, with a really short range of approx. 1 cm. They give high if they detect something. On the output side, we gave output to two L297, stepper motor controller, thourgh a buffer, and the to ULN2803, current amplifier, and then to the two stepper motors. Though we could had avoided L297, but t just made coding a little bit simpler. Also, we had DC motor connected through L298, which acts as a H-bridge, as we required bi-directional DC motor control, and a current amplifier as well. But he biggest rouble which is still there is, we are not able to run it on batreries, its getting too heavy with them, mayb we need better and lighter batteries, and that's the bigest drawback, being in pilani, lack of resources. Well, for electronics, me and gautam were there, supporterd by mr. L V Sumanth /* to be referred as Su here onwards */ for soldering.
Now for the algorithm we applied, we used Depth first search for exploring the maze and Breadth first search for finding the shortest path. I worked on the code just for interfacing, i mean I/O control. Rest, the algorithm part was taken care by karan bathla, the fourth member of the league.
And the mechnical design was completely handled by mr. Su. The mechnical part included chasis design and fabrication, which was done in my room only with aluminium :). And also, DC motor and small steering wheel was also his idea, when we gave up on castor. Though this mr. su is a comp sci student, his knowledge and understanding specially for automobiles is too good. A few pics of fabrication.
This wasnt the final circuitery, we resoldered it all.
And yeah.. the name.. we are stil lookig for a name for our mouse. When we went to mumbai, we called it 'Ram Bharose', and this new improved verison is called 'Mann Mauji', though not ofically. Still looking for some name.... suggestions are most welcome. And mayb if the name suggested by you is selected, you'll win a free lunch(box) from me :P.* So, our micromouse expert comittee :P /* in alphabetic order*/
Gautam Chaudhari
Karan bathla
L V Sumanth
Rishi Mathur
* Conditions apply. You need to apply for the contest through the prescribed form, which will be made available form a later date, which wil be intimated soon. I won't courier/parcel the gift. You'll have to collect that from me, and you'll have to notify me six working days in advance if you wish to claim your prize, after the contest results are declared FIND OF THE DAY : Why be difficult when you can be impossible
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