Grid Solving Robot

Introduction :

Grid solving robots are very useful in various robotics competitions. In this tutorial we would be dealing with how the grid follower robot works along with its algorithm. A grid follower is basically a line follower with a modified code which helps it in traversing a grid. Just as a simple line follower, a grid follower takes inputs from various sensors to detect its position on the grid.

Simple line follower can be made using controllers as well as without controllers.

   Making a line followers using controllers needs a programming skills.

 Microcontrollers can be programmed using c language or/and assembly language.

It is better to write programme in c instead of using asssembly .

 

line followers without microcontrollers can be made using various circuits.

one of them was designed by me 

simple line follower robot without microcontrollers

The Bot

Here we will be assuming that our robot is taken input from 5 different sensors.
Out of the 5 sensors 3 sensors will be primarily used for line following while the other two sensors would be used for detection of the intersections or nodes i.e. points where two lines intersect perpendicularly. The sensors can be used as per one’s choice either a led-ldr pair or infrared led receptor pair, etc. Here we will be assuming that when the sensor is on the white surface it gives a high output and accordingly when it’s on the black surface it will give a low output.

Microcontroller :

Various microcontroller's can be used as a brain of the bot :

1. 8051 and its derivative http://myelectronicsbook.blogspot.in/2012/08/microcontroller-8051-pin-description.html
2. AtmegaXX(8,16,32)

Sensors :

Any of these can be used : LED - LDR  

LDR is light dependent resistors. it is simply a resistors with a variable resistance. but its resistance depends on light. when light falls on resistors , resistance decreases . in dark conditions resistance increase,as there no avalability of light.

IR-Photodiode

IR - Phototransistor :
TCRT 5000 is ready made module available in electronic's shop . U just have to mention the part no. as "TCRT 5000 ".

MOTORS:
Normal dc motors can be used as actuator.
Stepper motors can be used for better accuracy.

Algorithm table

1	Sensor 2	Sensor 3	Sensor	Sensor 5
0	0	1	1	0	Take right turn
0	1	1	0	0	Take left turn
0	1	1	1	0	Keep going forward
0	0	0	1	0	Take left turn
0	1	0	0	0	Take right turn