This document discusses various applications of autonomous robotics including line followers, obstacle avoiders, mobile robots, gesture robots, and swarm robots. It describes sensors like IR reflective sensors that use IR LEDs and photodiodes to detect surfaces. DTMF signals are discussed as a method for controlling robots with phone keypads by generating dual tones. Accelerometers are described for measuring static and dynamic acceleration. Gesture control and swarm robotics using decentralized self-organized systems are also mentioned. RF modules operating at 434MHz are discussed for long range wireless communication between robots.

1. Autonomous robotics
APPLICATIONS

2. Content
 Line follower
 Obstacle follower
 Obstacle Avoider
 Mobile robotics
 Gesture robotics
 Swam robotics

3. 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).

4. 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

5. OPERATION OF A COMPARATOR

7. Cont.….
 After digitalizing the sensors’ data, it
is sent to micro controller for further
processing and execution.

8. Simple line follower

9. 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

10. The following fig. shows the frequencies used for each
signal

11. 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.

12. OVERVIEW

13. DTMF BASED MOBILE ROBOT

14. 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

15. 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

16. Working

17. OUTPUT RESPONSE VS ORIENTATION TO
GRAVITY:

18. GESTURE BASED RoBOT

19. 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.

20. 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.

21. RF Transmitter

22. The transmitted data is received by an RF receiver
operating at the same frequency as that of the
transmitter i.e. 434MHz.

23. SWAM ROBOT

24. ANY QUIRES?