UNDER THE GUIDENCE OF:-
Mr. Samiran Biswas
S u ub b m m i i t t t t e e d d b y y: : U N NI I V VE E R R I IT TY Y R O OL L L L N O O
A a a a A A As s ii s s h h k ku u m m a r r S Sh h a r r m m a A a A A Am m ii t t M Mo o n n d d a ll P a e a Pr r a t t ii k k D De b b n n a t th h R a a Ro o h h ii t t k ku u m m a r r M Mo o n n d d a ll
1 10 0 6 6 0 0 3 3 0 0 5 5 1 1 0 0 5 5 0 0 1 10 0 6 6 0 0 3 3 0 0 5 5 1 1 0 0 3 3 0 0 1 10 0 6 6 0 0 3 3 0 0 5 5 1 1 0 0 2 2 9 9 1 10 0 6 6 0 0 3 3 0 0 5 5 1 1 0 0 0 0 9 9
ACKNOWLEDGEMENT
We would like to express e xpress our heartiest gratitude to Mr.Samiran Biswas, Mr. Chandan Kumar Ghosh, Mr. Dipak Chakrabarty for providing us with their proper guidelines and supervision to perform our final year project in the 8 th sem .Then I would like to thank Subir sir, Mr. Biswajit Biswas for their continuous c ontinuous inspiration during the whole project.
We would like to thank the whole ECE Dept. Of MCET for their continuous cooperation and clarification of doubts while carrying out project work.
Our special thanks goes to all the faculty members and college administration, MCET for their assistance and encouragement.
I N D E X
S l l. N o o.
C o on n t t e e n nt t
P g .N o o.
1
What is Robotics
5
2
Aim & Desired Specifications
6
3
Metireal Req
7
4
Block Diagram
8
5
Circuit Diagram
9
7
Working of Robot
10-14
8
Mesurement at a Glance
15-16
9
Control & Locomotion
17
10
Applications & Limitaion
18
Conculation
19
Biblograph y
20
WHAT IS ROBOTICS Robotics is the science and technology of robot robot,, their design, manufacture, and application.Robotics requires a working knowledge of electronics, mechanics and software, and is usually accompanied by a large working knowledge of many ma ny subjects.A person working in the field is a roboticist. Although the appearance and capabilities of robots vary vastly, all robots share the features of a mechanical, movable structure under some form of autonomous control. The structure of a robot is usually mostly mechanical and can be called a kinematic chain (its functionality being akin to the skeleton of the human huma n body). The chain is formed of links li nks (its bones), actuators (its muscles) and joints which can allow one or more degrees of freedom. Most contemporary robots use open serial chains in which each link connects the one before to the one after it. i t. These robots are called serial robots and often resemble the human arm. Some robots, such as the Stewart platform, use closed parallel kinematic chains. Other structures, such as those th ose that mimic the mechanical structure of humans, various animals and insects, are comparatively rare. However, the development and use of such structures in robots is an active area of research (e.g. biomechanics ). Robots used as manipulators have an end effector mounted on the last link.
M A T UI R E TE R I IA L L R E EQ U ED
T he component list for making the robot is as follows:-
S.No Material Required Description
Quantity
1
LM358
Dual Op-Amp
3
2
NE555
T imer
1
3
SL100
NPN transistor
8
4
SK100
PNP transistor
1
5
7408
AND IC
1
6
7432
OR IC
1
7
Vector Board
1
8
DC motors
3
9
LDR
(Light dependent resistance)
3
10
IR Receiv er
(for heat)
1
11
32C
Power NPN transistor
2
C I R C A M GR RA CU I T D I A G ( 1)
C I R C 2 ) A M GR RA CU I T D I A G (
O R W RK KI N G O F F T H E R O OB O T B OT Obviously the line following robot will need to see the line, therefore we require an light detector of some sort. We also would like it if the t he line following robot could do this regardless of the ambient conditions (is the room dark or light? is it lit by sunlight or artificial light?). So the robot will also need its own illumination source. The weapon of choice here will be Infra Red (IR) light. To make this easy for ourselves the light only needs to be constant... if a white line is present then it will reflect a lot of IR from our source. If the line is black then we see the opposite effect.
THE CIRCUIT All we need is an IR source, an IR photo-transistor and a couple of resistors! Here are the resources: •
•
IR emmiters and detector pairs: IR emmiters and detector pairs: On top of these, it would be nice if the signal that we get could be TTL (on or off, 0V, 5V). So to do this we will also require our favourite BEAM chip, the t he 74AC240, heres the circuit:
Obviously the line following robot will need to see the line, therefore we require an light detector of some sort. We also would like it if the t he line following robot could do this regardless of the ambient conditions (is the room dark or light? is it lit by sunlight or artificial light?). So the robot will also need its own illumination source. The weapon of choice here will be Infra Red (IR) light. To make this easy for ourselves the light only needs to be constant... if a white line is present then it will reflect a lot of IR from our source. If the line is black then we see the opposite effect.
Circuit operation is simple.... no line to follow put the input to the inverter inv erter high, and therefore the inverter outputs a low, line detection turns on the transistor (or photodiode) and thus the inverter gets a low and outputs a high. If your robot is following a black line on a white page, then add another invereter after or before the first. So what should the values for R1 and R2 be? and how do I set up the 74AC240 chip exactly..... The value for R1 affects the source IR brightness, for maximum brightness
we set R1 to give the maximum allowable forward current for the IR led. So what should it be?? Well, look at the datasheet for your LED, lookup the value of the maximum forward current. Now a simple bit of electronic theory tells us V=IR, I will assume you are using us ing 5V because this is the volatge the 74AC240 should be run at (6V is OK... 4 AA batteries). Now lets say that the max forward current is 100mA so we have 5V = 100mA * R , therefore: 5/100*10^-3 = R = 50ohms. Experiment with different values until you get a sensitivity that you are happy with... too bright and the detector will see it when it shouldn't! Also remember this will affect the distance you can have it from the line you are following. So how about R2? just set R2 to about 4K. The chip setup is simple too... ground pins 1, 10 and 19, put 5V onto pin 20. Now choose a pin to input your signal to, if we look at the 74AC240 datasheet on page 14, we will see a connection diagram, any pin with an I is an
input, follow it across to find fi nd its output. Pins 1 and 19 are the enable pins, which we have h ave grounded to permanently enable the inputs on both side of the chip, this leaves you free to use any of the input pins. For example (in case I haven't h aven't spelt it out enough already)... input your signal at pin 4 and take the ouput from pin 16. The output signal could be used to directly drive your motor... just connect one side of the motor to the ouput, and the other side to ground. If you do this for two motors (2 sets of line detectors will require two sets of emitters and detectors, but only one 74AC240 chip), then you have a basic line follower already! The left detector should be used to drive the right motor and vice versa The behaviour of this robot as it stands will be too turn a motor on IF a line is present, if both detectors are over the line then it will drive straight, if the left detector goes of the line, it will turn off the right motor causing the robot to turn back onto the line, if the right detector goes off the line then it will turn off the left motor and again go back onto the line. If both detectors come off the line (end of line) then the robot will stop altogether, perfect!
74HC240 • 74HCT240
- OCTAL BUFFER/LINE DRIVER WITH 3 - STATE OUTPUTS
General Description The AC/ACT240 is an octal buffer and line driver designed to be employed emp loyed as a memory address driver, clock driver and bus oriented transmitter or receiver which provides improved PC board density.
Features _ ICC and IOZ I OZ reduced by 50% _ Inverting 3-STATE outputs drive bus lines or buffer memory address registers _ Outputs source/sink 24 mA _ ACT240 has TTL-compatible inputs
MEASUREMENT AT A GLANCE •
Height of the base from ground grou nd = 8.7 cm
•
Diameter of the wheel = 3.2 cm
•
Free space = 0.1cm
•
Width of wooden base = 0.5 cm
•
Breadth of base = 17.6 cm
•
Length of lower base = 23.7 cm
•
Number of motors used = 3
•
Revolving base : Breadth =15.5 cm Length= 30.7 cm
•
Length of arm =31cm
•
Length of grabbing hand = 9.6cm
•
Maximum extendable length of grabbing hand =10cm
The bot rests upon four wheels. Out of four wheels, the two rear wheels are driven by two separate geared motors of 100 rpm each which are connected on the same axis. The D.C motors are operated at 12 volt with normal power supply of 220- 230 volt using a Switched Mode Power Supply (SMPS). The wheels can rotate in both clockwise and anticlockwise direction. The rest two front wheels can rotate 360 degree on both ways to support the bot in any direction. Left and right movement of the bot is due to free rotation of front wheels keeping the left and right rear wheels constant at one time respectively .
UPPER BASE Above the lower base of the bot, the turn table platform is of 30.7 cm length and 15.7 cm breadth. The upper revolving base is connected with an arm which lifts and lowers down the material and also keep the blocks in horizontal and vertical position. The turn table is rotating in both directions through a geared motor of 10 rpm. Horizontal movement of the arm depends on the clockwise and anticlockwise movement of the motor shaft of the turn table. The motor is actually fixed with the lower base keeping the shaft at a certain height. This shaft has got a rubber padding on its tip. turntable there is a rubber padding.
CONTROL The mechanical structure of a robot must be controlled to perform tasks. The control of a robot involves three distinct phases perception, processing and action (robotic paradigms). Sensors give information about the environment or the robot robo t itself (e.g. the position of its joints or its end effector). Using strategies from the field of control theory, this information is processed to calculate the appropriate signals to the actuators (motors) which move the mechanical structure. The control of a robot involves path planning, pattern recognition, obstacle avoidance, etc. More complex and adaptable control strategies can be referred to as artificial intelligence .
LOCOMOTION For simplicity, most mobile robots have four wheels. However, some researchers have tried to create more complex wheeled robots, with only one or two wheels. •
•
Two-wheeled balancing: While the Segway is not commonly thought of as a robot, it i t can be thought of as a component of a robot. Several real robots do use a similar dynamic balancing algorithm, and NASA's Robonaut has been mounted on a Segway. Ballbot: Carnegie Mellon University researchers have developed a new type of mobile robot rob ot that balances on a ball instead of legs or wheels. "Ballbot" is a self-contained, battery-operated, omnidirectional robot that balances dynamically on a single urethane-coated metal sphere.
APPLICATIONS 1. The robot can be used as a guider to guide the visitors from the entrance to the main office . 2. It can help doctors to carry the medicines from one ward to another . 3. The main purpose is to rescue the people by extinguishing fire in a building . 4. When man power does not work to rescue then the robot can done this job.
LIMITATIONS AND EXTENSIONS
In the present condition it can extinguish fire only in the way and not in all the rooms. It can be extended to a real fire extinguisher by replacing the fan by a carbon-di-oxide carrier and by making it to extinguish fires of all the room using microprogramming. Also the robot could not be run through the batteries because at some conditions the current requirement for the circuit rises to about .8A which is very high and can not be obtained using batteries.
CONCUL AT AT ION ION
We made it possible using various electrical and mechanical components. It includes in total five geared motors of varying rpm. We have made a differential steering set-up for the various movements of the lower base. The other movements of the upper base, arm and the grabbing system is provided by mechanical coupling, pulley system and a pivoting system respectively. Ball bearing, free rotating wheel etcetera are used for the movement of the bot. For the electrical connection part we had used switches, relays, connecting cables, and other components. In our journey we had met with several problems, especially while working with the grabbing part. We solved most of the problems and finally arrived up till this. Moreover all type of electronic goods were not available in our nearby market and for small things we had to travel a long way from Behrampore to Kolkata. However it was fun working in such an innovative and energetic team. Finally we present to you, MASS, our robot. Though it looks somewhat poverty stricken due to its rickety limb, it is capable of performing its task in an efficient way. We had just tried to utilize our meager resources optimally .
BIBLIOGRAPHY These are some of the sites we visited:http://www.hobbyengineering.com/rmapIndex.html http://www.ridgesoft.com/buildingbots.htm http://www.seattlerobotics.org/guide/infrared.html http://www.robotroom.com/RBFB.html //line following http://www.robotroom.com/RBFB.html robot http://www.mstracey.btinternet.co.uk/interest.htm http://www.dudi30.republika.pl/galeria/index.html //New robot every week http://www.robotics.com/robomenu/index.html
THANK YOU
