An Obstacle Avoiding Vacuum Cleaner Robot (MAE 4733 Term Final Project Report)

An Obstacle Avoiding Vacuum Cleaner Robot COURSE NO. : ME-362 INSTRUMENTATION AND MEASUREMENT SESSIONAL

DEPARTMENT OF MECHANICAL ENGINEERING BANGLADESH UNIVERSITY OF ENGENEERING AND TECHNOLOGY

SUPERVISED BY: DR. M. A. TAHER ALI PROFESS0R, DEPT. OF MECHANICAL ENGINEERING, BUET.

DR. MD. ABDUR RASHID SARKAR PROFESS0R, DEPT. OF MECHANICAL ENGINEERING, BUET.

DR. MUHAMMED MAHBUBUR RAZZAQUE ASSOCIATE PROFESS0R, DEPT. OF MECHANICAL ENGINEERING, BUET.

A.K.M. MONJUR MORSHED ASSISTANT PROFESSOR , DEPT. OF MECHANICAL ENGINEERING, BUET.

MD. AL-AMIN KHAN CHOWDHURI LECTURER, DEPT. OF MECHANICAL ENGINEERING, BUET.

MD. WASIM AKRAM LECTURER, DEPT. OF MECHANICAL ENGINEERING, BUET.

ABDUL MOTIN LECTURER, DEPT. OF MECHANICAL ENGINEERING, BUET.

ACCOMPLISHED BY GROUP NO. B17 GROUP MEMBER SHUVRA BANIK (Team Leader)

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MD. JUBAYER HOSSAIN

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MD. YEASIN BHUIYAN

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MD. NURUZZAMAN BHUIAN

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ACKNOWLEDGEMENT Starting with the name of Almighty we would like to pass our gratitude to him for completing our project timely and successfully. Beginning from the project proposal, the journey was never easy for us all the way through. With the very little knowledge and experience, it was always going to be tough for us. Without the help of few generous people, all our hard work would have gone into vain. First of all, we would like to express our heartiest gratitude to our course teacher Dr. Md. Abdur Rashid Sarkar sir. He was always there in our aid, as far as advices and suggestions are concerned. We are also grateful to A.K.M. Monjur Morshed, Md. Al-amin Khan Chowdhuri, Md. Wasim Akram, Abdul Motin for helping us in different prospect of our project. Assistant instrument engineer of Instrumentation and Measurement lab, Mr. Masudur Rahman is one person whom we would never forget to mention. He was ever so cordial and goodhumored to serve us with whatever we needed. We are also thankful to the lab assistants of the machine shop, welding shop and carpentry shop, who helped us in constructing the project. Last but not the least, we should not also forget our friends and classmates who continuously encouraged us and shared their ideas.

CONTENTS TOPIC

PAGE NO.

INTRODUCTION

01

ABSTRACT

02

OBJECTIVES

03

BASIC COMPONENTS

04

MECHANICAL COMPONENTS

05-07

ELECTRICAL COMPONENTS

08-12

OTHER ELEMENTS

13

WORKING PRINCIPLES

14-19

APPLICATIONS & COMMERCIALIZATION LIMITATIONS

20

COST ANALYSIS

22

CONCLUSION

23

REFERENCES

24

21

INTRODUCTION As engineering practice goes mainly for autonomous control over expected operations, robotic appliances have a vast field of applications. In other words, it is the heart of mechanical engineering. A vacuum cleaner is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors or carpets. Most homes with carpeted floors in developed countries possess a vacuum cleaner for cleaning. These are the conventional human pushed vacuum cleaner. But we thought in a different way. A robotic vacuum cleaner is the first step towards our thoughts. A robotic vacuum cleaner is meant to supplement a standard, humanpushed vacuum cleaner. It drives around the room autonomously to clean it. It will start cleaning when the power button is switched on. Whenever there is any obstacle in front of the cleaner it just changes its direction automatically and goes in the other way. It has also got the ability of automatic shut down. The cleaning part of our project is based on Bernoulli's Principle, which states that as the speed of air increases, the pressure decreases. Air will always flow from a high-pressure area to a low-pressure area to balance out the pressure. The robotic part is microcontroller based. The obvious outcome of the combination of these two parts is the robotic vacuum cleaner and that’s our ultimate objective.

ABSTRACT A vacuum cleaner is not a new concept in the field of mechanical engineering, but when it comes about a robotic vacuum cleaner, it’s something new and different. It’s not like the conventional human pushed vacuum cleaner. It has got an autonomous control with the ability of avoiding obstacle. The vacuum cleaner has an intake port where air enters and an exhaust port where air exits. A centrifugal fan inside the cleaner, forces air towards the exhaust port at a high speed, which lowers the pressure of the air inside according to Bernoulli's Principle. This creates suction - the higher pressure air from outside the vacuum rushes in through the intake port to replace the lower-pressure air. The incoming air particles rub against any loose dust or debris from the floor or carpet and carry these in the exhaust port which is a glass box. There are two holes in the box covered with nets. The dirt is trapped in the nets, but the air passes right through the holes to the environment. A brush is placed at the intake port, which kick dust and dirt loose from the carpet so it can be picked up by the air stream.

OBJECTIVES The main objectives of our project are: → To model a vacuum cleaner with robotic control. → To save time and power by automatic control. → To make the task of cleaning easier. → To come up with some new ideas concerning vacuum cleaning.

BASIC COMPONENTS: The basic elements, we used are of two types : 1. Mechanical Components 2. Electrical Components

Fig: A conventional vacuum cleaner

1. Mechanical Components :  SPECIALLY DESIGNED FAN : The fan is so designed that it can create pressure difference between bottom and upper portion. It is a backward curved type centrifugal fan. It is rotated by a motor.

Fig: Specially designed fan

 WHEELS : Four wheels are used in this project .The front two wheels are given power & are controlled by two motors .Two revolving wheels are also used for bearing loads placed on the board.

Fig: Nylon wheel and revolving wheel

 D.C. MOTOR : An electric motor is a machine which converts electrical energy into mechanical energy. Its action is based on the principle that when a current-carrying conduction is placed in a magnetic field, it experiences a mechanical force.

Fig: DC motor

 GEAR MOTOR : We used two gear motors to control the two front wheels individually.

Fig: Gear motor

2. ELECTRICAL COMPONENTS : **

CIRCUIT ELEMENTS

**

 RESISTORS : A device which is us used to resist current in an electrical circuit. Resistors can be made from different material. But the most common is carbon composition (Graphite plus binding agent).Basically it is small and thin section of carbon composition with Lead at each end. Resistance is measured in Ohms & is represented by the Greek symbol Omega. To abbreviate a bit ,prefixes are generally used to indicate a multiplier or resistance value. Typically we see just two of these : K=thousand ; 1KΩ =1,000 Ω M=million ; 1MΩ =1,000,000 Ω =1000 KΩ

Fig: Resistance 

VARIABLE RESISTANCE : Variable resistance shows different values of resistance in different position within a predefined range. In our circuit we used 100 kΩ variable resistance.



L.E.D. ( Light Emitting Diode) : It is one kind of color bulb.It emits visible light when current passes in forward direction.It also has polarity.Generally it can withstand 5 to 25 mA of current.So , a fixed variable resistor is used in series for it’s safety.

Fig: LED 

MOSFET : The ‘’metal oxide semiconductor field effect transistor’’ is a device, used to amplify or switch electronic signals. It is by far the most common field effect transistor in both digital & analog circuits. It is composed of a channel of p-type & n-type semiconductor material & is accordingly called a PMOSFET & an NMOSFET. → IRF840 is used to drive each dc motor connected with two front wheel. →33 A , 100V , 0.04 Ω , N-Channel Power MOSFET →Ultra low On-Resistance

Fig: Mosfet



MICRO-CONTROLLER: ATmega-8 microcontroller is used in our project. The feature are given below :

Fig: Micro-controller

Fig: Pin configuration 

IC (INTEGRATED CIRCUIT) 7805 : Some types of chips are particularly sensitive to voltage fluctuations. The 7805 power regulator will take any voltage between 6V and 12V DC and turn it into a smooth 5V to power the chips. The easiest method of building the circuit is on and electric breadboard. They are available at all electronics stores.



IR (INFRA-RED) TRANSMITTER : It is used to send infra-red which will be reflected somehow if there is an object in front of it.



IR (INFRA-RED) RECEIVER : It is used to receive the infra-red which has been reflected towards it and it makes a corresponding voltage change.

Fig: IR transmitter & IR receiver

 Project board : Project-board is used to connect all the circuit elements

Fig: Project board

** OTHER ELECTRICAL ELEMENTS **  BATTERY

: A 12V battery is used to supply the power required.

 WIRES :

Wires are used to connect all the electrical components to make a complete circuit .

WORKING PRINCIPLE : Working principle of this cleaner robot can be divided as follows: 1)Mechanical Part 2)Circuit & Programming Part

1. Mechanical Part : Basic Principle : Vacuum cleaners work because of Bernoulli's Principle, which states that as the speed of air increases, the pressure decreases. Air will always flow from a high-pressure area to a lowpressure area, to try to balance out the pressure. A vacuum cleaner has an intake port where air enters and an exhaust port where air exits. A fan inside the vacuum forces air toward the exhaust port at a high speed, which lowers the pressure of the air inside, according to Bernoulli's Principle. This creates suction - the higher pressure air from outside the vacuum rushes in through the intake port to replace the lower-pressure air. The incoming air particles rub against any loose dust or debris from the floor or carpet and carry these in the exhaust filter bag made of porous woven material (typically cloth or paper). The dirt is trapped in the filter bag, but the air passes right through the bag to the environment. Some vacuum designs also have rotating brushes at the intake port, which kick dust and dirt loose from the carpet so it can be picked up by the air stream → We use the specially designed fan to creating vacuum. The fan is rotated by a DC motor. So dust is suck from bottom to upper portion & is stored at a particular place inside the transparent glass box. → Two front wheels are controlled individually by two motor for movement at various places. Rear wheels are used just to bear the loads (Battery, Transparent glass box etc.) placed on the small vehicle. They are not given power.

2.Circuit &Programming part :

CIRCUIT DIAGRAM :

Programming Part: The code is written in Programming language C in AVR Studio 4. PonyProg 2000 software is used to download the program from computer to the micro-controller. The code is given below :

#include #include

double ADC_value; int a,b; int test=0;

ISR(ADC_vect) //Interrupt function { ADC_value = ADCL; ADC_value += (ADCH