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)
#0510094
MD. JUBAYER HOSSAIN
#0510077
MD. YEASIN BHUIYAN
#0510085
MD. NURUZZAMAN BHUIAN
#0510086
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<<8); ADC_value = ADC_value * 100; ADC_value = ADC_value/1024;
if(ADC_value>40) //If the voltage drop across LED is more than 2 volts { for(a=0;a<1000;a++)
{
for(b=0;b<500;b++) //The robot will turn left for 5 seconds
{ PORTD=26; //Decimal form of 11010 } }
PORTD=23;
if(test>5) //Will stop robot after facing obstacles for 5 times { PORTD=0; //All output is stopped
while(1) {} } test++; } ADCSRA |=(1<
}
void ADC_init() //ADC function {
ADMUX |=(1<
}
int main() {
DDRD=0xFF; //PORTD is declared as output int x,y;
while(1) { for(x=0;x<1300;x++) {
for(y=0;y<1000;y++) //The robot will move forward for 13 seconds {
PORTD=23;
//if there is no obstacle
//Decimal form of 10111
ADC_init(); sei(); while(1) {} } } }
return 0;
}
//ADC is called //Global interrupt begins
APPLICATIONS & COMMERCIALIZATION
Automatic house cleaning Suitable for office and industries Is possible for commercialization High scale production will reduce the per unit cost
LIMITATIONS
:
We are not out of limitations. IR sensor does not work efficiently in the daylight. Heavy weight of the cleaner has decreased the speed. Insufficient power supply has decreased efficiency.
COST ANALYSIS As we did this kind of project for the first time, some money has been wasted where there was no reason to spend that. Without this all money was spent efficiently. A list of all the things we used in our project and their prices are given below: SL NO. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
PURPOSE
QUANTITY
COST(Tk.)
Centrifugal fan DC Motor Gear Motor Wheel Base Micro-controller IR Transmitter IR Receiver Mosfet IC -7805 LED Battery Project board Net &Wire Switch Transparent glass box TOTAL
1 1 2 4 1 1 1 1 3 2 3 1 2 1 1
500 600 900 250 100 80 15 15 90 20 3 420 420 40 10 600 4063
CONCLUSION Nowadays every technical branch of applied science looks for commercial application. A robotic vacuum cleaner can be a good example of that. A wide application of this project can make our daily life easier. On finishing our ME-362 course, we can say that, it had been a great experience for all of us. It was something new anything new has always some adventure and enthusiasm associated with it. We felt the heat of it as well. At last we feel like mechanical engineers! Before this project, we hardly had any experience of working together to accomplish a certain task by our own. We were very lucky to be member of the same group and it was a joy to work aside friends. We came to know how to gather necessary resources and assemble them to achieve the goal. This was the first time we could blend our innovation and knowledge too. At the end of the project, we feel proud and happy that we have stepped a foot forward towards our professional life. Once again thanks to all the people, who have helped us in one way or another to make our project successful.
REFERENCES From time to time we took help from different types of books and websites. The list of references from which we really got some help is as follows: 1. http://www.societyofrobots.com/ 2. http://home.howstuffworks.com/ 3. http://www.wikipedia.org/ 4. Mechanical Measurements By-Thomas G. Beckwith -Roy D. Marangoni -John H. Lienhard
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