Line Follower and Obstacle Detector Robot

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Abstract

To construct a Line Follower & Obstacle Detector Robot based on a group of Integrated Circuits. A pair of IR Emitter & Receiver is used to guide the intelligent system throughout the track. Data from the sensing arrangement is feeded to the OP-AMP (LM-324), which is further feeded to the AND IC (IC-7408) for conditioning. The conditioned data is then directed to the motor driver IC (L293D) to drive the gear motor.

Introduction:

  • Robotics has become a very common application in most of the developed countries. High performance, high accuracy, lower labor cost and ability to work in hazardous places has put robotics in an advantageous position over many other technologies.
  • The main idea of this project is to design and build an autonomous line following robot, which is capable of following a white line drawn on a black surface. It has an infrared sensor system and logic gates to guide the robot along the black line. The black line and white surface is detected by the IR sensors whose signals are sent to respective logic gates which locates the black line and keep it on track and a motor driver which is responsible in maneuvering the robot.

Objectives:

The aim of the project is to design and build a line following autonomous vehicle consisting of track sensors which enables it to follow a track that consists of white line on a black surface and detecting the obstacle. The objectives of this project are as follows:

 • Capable of following a line and taking various degrees of turns.
 • Detection of obstacle ahead of it 
 • It must be prepared of a situation that it runs into a territory which has no line to follow.
 • Insensitive to environmental factors such as lighting and noise.
 • Must allow calibration of the line’s darkness threshold.
 • Reliability and speed control capability.
 • The color of the line must not be a factor as long as it is darker than the surroundings.

List of Components:

  • IR Sensor 
  • LM324
  • L293D Motor Driver IC 
  • IC-7408
  • Gear Motor 
  • Battery

Block Diagram:






Circuit Diagram:

Circuit Diagram of a LFR


Working Principle:

  • Here we have used a 7408 IC which is simply an AND gate. This takes two digital inputs and produce a single output besides a single IC-7408 has four and gates and we just need two of them. First the output from the IR sensor is supplied in such a manner that if no obstacle comes in the way of the IR Sensor then the output of the OP-AMP is high or +5volt. Then this output is supplied to the two AND gates. So to make each one input of the two gates becomes 1. For tracking the line another one comes from the left IR sensor & the right IR sensor. This is done in the manner that if the IR gets the reflected light the output of the OP-Amp becomes high means 1 logic for the two AND gates.
  • Now if no obstacle detects at IR sensor & both sensor side on white surface then our robot will go forward. If the left sensor gets black line the corresponding left motor will stop while the other will continue. This makes the robot to turn left. Similarly if the right sensor gets black ling the corresponding right motor will stop while the lest will continue. This makes to turn the bot at right direction. 
  • If the IR sensor detects any obstacle at its path one of the inputs of the two AND gates becomes 0 volts or logic 0 this will make the two outputs of the AND gates 0 logic this makes a hard break to the robot by turning the two motor stop.

Constructional View:


Side view & rear view of my LFR


Applications:

  • Industrial automated equipment carriers.
  • Automated cars.
  • Production automation system.
  • Tour guides in museums and other similar applications.
  • Instant crash avoider.
  • Entertainment and small household application.

Advantages & Disadvantages:

  • It can be used to follow tracks by taking various turns.
  • It can detect obstacle ahead it.
  • As it not made up using microcontroller, it is not responsive to The sensitive turns.
  • It can’t follow turns of 90’.

Future Prospects:

  • It could be interfaced to other hardware devices to work as a automated vehicle .
  • It could be used for collecting data from any inhabitable atmosphere where human being can't reach.