DUAL M

ODE

OBSTACLE

AVOID

ING

ROBOT

G U I D E D B Y: -

M R . A J I T H J O S E P H

D O N E B Y : -

V I S H N U R A J

R O S H A N S E B A S T I A N

M A N E E S H K U M A R M M

S H U H A I B P A

INDEX

1. OBJECTIVE

2. REQUIREMENTS

3. BLOCK DIAGRAM

4. BLOCK DIAGRAM DISCRIPTION

5. ADVANTAGES

6. APPLICATION

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OBJECTIVE

The objective of this project was to develop a Collision Avoidance. Mobile robot with onboard sensors and a Microcontroller.

The mobile robot designed is capable of moving in an environment which has obstacles avoiding collisions.

The Mobile robot uses the Infrared transmission Method for Obstacle avoidance.

The Algorithms runs on the PIC microcontroller based on the information received by the IR receiver .

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REQUIREMENTS

1. PIC 16F877A microcontroller

2. HT12E encoder

3. HT12D decoder

4. LM324 op-amp

5. L293D motor driver

6. IR transmitter

7. IR receiver

8. 7805, 5V regulator

9. 5mm LED10. 1N4007 rectifier diode11. ASK transmitter module12. ASK receiver module 13. 4MHz crystal14. 12v , 100-rpm geared motor15. Various passive and active devices.

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BLOCK DIAGRAM

REMOTE ROBOT

SWITCHES

RF TRANSMIT

TER

RF RECEIVE

R

HT12DECODER

OBSTACLE

DETECTOR

PIC16F877A

MOTORDRIVER

m1

m2

ANTENNAANTENN

A

IRSENSOR

HT12ENCOD

ER

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When a button is pressed in the remote, the corresponding code is transmitted through RF transmitter.

At the receiver end, this transmitted signal is received and decoded.

The MCU unit compares the received code and drives the motors corresponding to the code received.

Obstacle detectors detect any object in the way and intimate the microcontroller.

BLOCK DIAGRAM DISCRIPTION

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HT12 ENCODER/DECODER

Used to interface RF transmission and reception.

The encoder/decoder have same number of addresses and data format.

 HT12E converts the parallel inputs into serial output.

It encodes the 12 bit parallel data into serial for transmission through an RF transmitter.

These 12 bits are divided into 8 address bits and 4 data bits.

HT12D converts the serial input into parallel outputs

The serial input data is compared with the local addresses three times continuously.

The input data code is decoded when no error or unmatched codes are found.

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RF MODULE/ASK MODULE RF can travel through larger distances

RF signals can travel even when there is an obstruction between transmitter & receiver.

Amplitude-shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave.

The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the amplitude of the received signal and maps it back to the symbol it represents, thus recovering the original data.

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

The transmission occurs at the rate of 1Kbps - 10Kbps

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PIC16F877A

• 8-BIT MICOCONTROLLER

• 13-BIT ADDRESS LINE

• RISC

• HAVARD ARCHITECTURE

• 35 SET INSTRUCTION

• FLASH PROGRAM MEMORY

• EEPROM 256 BYTES

• RAM- 368 BYTE

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CONTROL BLOCK Contains pic microcontroller(pic16f877a).

Receive input transmitted , input from IR sensor and input from decoder and give necessary output to motor driver ic.

MOTOR DRIVER IC L293D is used.

L293D is a dual H-bridge motor driver integrated circuit

 Motor drivers act as current amplifiers since they take a low-current control signal and provide a higher-current signal

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SENSOR

The sensor used is a  IR sensor, they detect the obstacle by emitting IR ray .

IR LED  transmits infrared rays in the range of 760 nm wavelength.

A small amount of IR energy is reflected by objects in front of the device and returned to the detector.

The IR detector is a photodiode

The IR receiver connected to a op-ampl sends these reflected signals to microcontroller

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MECHANICAL STRUCTURE

The base chosen our robot is metallic . The base is light weight , yet strong .

The motors used are gear motor itself which need a voltage of  12V.

The motors are strong enough to drive the base even with a weight on it.

Three wheels have been used , one at the front and two at the back. The back wheels are toy car wheels and the front wheel is the free wheel

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ROBOTIC MOVEMENT

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ELECTRICAL STRUCTURE

We are using a 12V battery since this is the maximum voltage that we need for our circuits.

The power supply converts the 12V from the batter to 5V since micro controller only needs 5V.

IC 7805 is used as voltage regulator.

Voltage regulator provides +5 v constant output.

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ADVANTAGES

Mobile robots perform various tasks to serve humans.

No human guidance is required in automatic mode.

This sort of project is very much useful in the industries where the automated supervision is required.

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APPLICATION

1. Driverless vehicles running along beams

2. Obstacle Detection for a Mining Vehicle

3. Obstacle detecting system for a motor vehicle

4. Autonomous cleaning robot

5. Use as a fire fighting robot

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THANK YOU ..

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