How to make a simple line following robot

I'll explain how to build a 'Line Following Robot step by step.

                                         

It is better if you have any basic knowledge about electronics,such as reading resister color code,soldiering, familiar with circuit symbols,polarity of capacitors,diodes etc..

If you are not familiar,then use following links to learn about them before read this page

• Reading resister color code
• Soldiering
• Circuit symbols

As the first step of line following robot,we have to make the chassis of it.

Following conditions should be considered before making the chassis of the bot.

1. Weight.
2. Moment of  inertia.
3. Center of gravity.
4. Wheel size.

Since we are planing to make a normal line following robot,we do not need to consider above conditions heavily.

1. Weight   :-It is better if the robot is light weight.Because it is easy to control when its' weight is low.Also it helps to save energy of battery.
2. Moment of inertia  :-It is hard to control robot movements when moment of inertia is high.so keep heavy items such as batteries,motors etc as close to robot center as possible.
3. Center of gravity  :-To accelerate/decelerate robot weight should on its tires.If there is no weight on tires -> no grip.So center of gravity should close to the axle of wheels.C.G. should be low as possible.You can use Lighter or slimmer motors to lower c.g.
4. Wheel size  :-Bigger wheels higher the c.g.smaller wheels lower the c.g.Keep wheels & shaft as light as possible.Wider wheels are hard to turn.

Lets select motors and wheels,

• Motor   :-This is a 500rpm geared DC motor.You can use this kind of motor or any kind of 12v DC geared motor.

• Wheels :-I used 29*5*3.9mm Rubber Car Tire Toy Pulley Wheels bought from ebay.