Line following Robot

Line following RobotSimple Line Follower robotIt is a simples robot that follows a line, either in a black line or white surface or vice-versa. (decide it)In this slide we will teach you how to make the line follower robot move following the line combine with a type of feedback mechanism to control the direction. Its the basic example of small intelligence robot, actually it focus on the designers intelligence!!Moreover we will make this project into modular so that it can be easily modified in future.The main electronics components that will be used for sensing are two LDRs, the transistors circuit are used to drive the DC motor.

Works involveDesign the mechanism, chassis and body of the robot (hardware) making a chassisKnow the working principle of component able to test the componentInstall and make a wiring for electronic sensor and motor driverCalibrate the sensing device according to high and amount of colour receiveTest run and make some modification/adjust if needed.Making a ChassisIts basically the frame of the robot on which motors and wheels are mounted and all the circuitry part is also placed on it.For base, you can use any material such as playwood, palstic or acrylic sheet of dimension 14x13cm square and thickness of 4mm for our chassis, it can be easily available at any picture frame shop.Or even old toy car can be reused for the body as what we did.

Drive Mechanism layoutWe will be using a fore wheel with a different drive using two motors , One motor used to drive two fix wheel and the other motor to drive two moveable wheel (directional wheel). linkagesThe Direction of the wheel motors can be controlled by changing the rotation of the motor. With help of cam the linkage will turn left or right according to the direction of motor 2

Direction wheelFixed wheelSensor 2 setcamMotor 1Motor 2Linkages)Working Principe -Light Sensor

Particularly we used Light dependent Resistors (LDRs) to detect black line on white surface. The logic is simple. Left sensor will be controlling left motor, when the sensor is on white surface motor will be switched on else switched off, similarly right motor is controlled by right sensor. Motor movement and sensor

LED & LDRThe light sensors must be placed on the robot is such a way that they are very close to the ground. Alignment side by side to the black lineThe are two parts of the circuit, first part would be LDR and LED pairs. These are to be soldered on a small general purpose board and mounted just in front of caster wheel facing downwards. This circuit is connected to the second part. Ensure that distance between two LDR must be 4-5mm greater than the width of the black line. It is necessary to cover the LED LDR pair with some absorbing material in order to avoid ambient light (environment light) to fall on LDR and distort the result

Know your component - guide lineIC 7805T pin setup

Transistor D880

Variable resistance (POT)

LDR

diode

Test the component

LDRPOT-Variable resistance

DARK sensor

Complete circuit