Autonomous roboticsAPPLICATIONS

Content

Line follower

Obstacle follower

Obstacle Avoider

Mobile robotics

Gesture robotics

Swam robotics

Sensors IR reflective sensors have an emitter (IR LED-

TX) and a receiver (Photo diode).

If white surface is present beneath the IR LED,

IR rays are reflected and are sensed by the

receiver i.e. photodiode (refer fig1).

While in the case of black surface, the light gets

absorbed and hence receiver (photodiode) does

not sense any IR rays (refer fig2).

ILLUSTRATION OF THE SENSOR WORKING

MECHANISM Let us consider Rs to be the resistance of the

receiver (Photo Diode),

As discussed earlier the Rs value varies for

different intensities falling on the photo diode,

let us assume the values of Rs to be ->

Rs=150Ω without light (black surface)

Rs=10kΩ with light (on white surface)

On black surface-

Vp= [Rs/ (Rs+R)*Vcc] = [150/

(150+10)]*5V=4.68V

On white surface-

Vp= [Rs/ (Rs+R)*Vcc] = [10/

(10+10)]*5V=2.5V

OPERATION OF A COMPARATOR

Cont.….

After digitalizing the sensors’ data, it

is sent to micro controller for further

processing and execution.

Simple line follower

DTMF (Dual Tone Multi frequency) DTMF is a process used in the telephone system. While dialing the number to recognize

the key on the phone’s keypad, the key will generate two simultaneous tones, these tones

are decoded by the DTMF decoder (Telephone exchange) and determine the key which

was pressed.

There are sixteen DTMF signals in total. These are divided into two groups

1) high group frequencies

2) low group frequencies

The following fig. shows the frequencies used for each

signal

OUTPUT

A DTMF decoder circuit distinguishes the

frequencies produced by the keypad and

produces the binary sequence equivalent to the

key pressed in a DTMF keypad.

DTMF signal can be tapped directly from the

microphone pin of a mobile phone device.

Cut the microphone wire and you will get two

wires. The one wire is the DTMF input other is

the ground to the circuit.

The signals from the microphone wire are

processed by the DTMF decoder IC which

generates the equivalent binary sequence as

parallel outputs - Q1, Q2, Q3, and Q4.

OVERVIEW

DTMF BASED MOBILE ROBOT

ACCELEROMETER

It’s an electromechanical device that measures acceleration forces and tilt angles by

using the MEMS (Micro Electro Mechanical Systems) technology, where acceleration is

the rate of change of velocity with respect to the time.

Acceleration forces are of two types

1) Static acceleration

2) Dynamic acceleration

CONT….

STATIC ACCELERATION:

Static acceleration is the constant force of gravity and by measuring the amount of

it, one can find out the angle at which the device tilted (with respect to the earth).

Example: Gravity pulling at your feet.

DYNAMIC ACCELERATION:

Dynamic acceleration is the dynamic (variable) force of gravity and by measuring

the amount of it, one can analyse the way the device is moving.

Example: Moving Car

Working

OUTPUT RESPONSE VS ORIENTATION TO

GRAVITY:

GESTURE BASED RoBOT

INTRODUCTION TO SWAM ROBOTICS

Swarm intelligence (SI):

is an artificial intelligence technique based

around the study of collective behavior in

decentralized, self-organized systems.

Swarm robotics

A large number of micro-robots that capable of

performing tasks that are not possible with

either a single micro-robot, or with a small

group of micro-robots.

RF MODULE

RF module operates at Radio frequency i.e. between 3 kHz & 300 GHz.

In this RF system, the digital data is represented as variations in the amplitude of

carrier wave. This kind of modulation is known as Amplitude Shift Keying (ASK).

RF module consists of an RF Transmitter and an RF Receiver, where the

transmitter/receiver (Tx/Rx) pair operates at a frequency of 434MHz.

RF transmission is more strong and reliable than IR transmission

RF communication uses a specific frequency unlike IR signals which are affected by

other IR emitting sources.

Signals through RF can travel through larger distances making it suitable for long

range applications.

RF Transmitter

The transmitted data is received by an RF receiver

operating at the same frequency as that of the

transmitter i.e. 434MHz.

SWAM ROBOT

ANY QUIRES?