ABSTRACT
“A robot is a reprogrammable,
multifunctional manipulator designed to move materials, parts, tools or
specialized devices through variable programmed motions for the performance of
a variety of tasks”
Robot is an
intelligent and human operated self controlled.
Robotics has
made a revolution in the field of industry and in many domestic applications. Robotic
plays a vital role such as cooking, serving and majority robots used in field
of industry and industrial applications.
Some of the
industrial applications are in automobile industries, beverages manufacturing
industries, aero-space industries, computer assembly, and .etc
We have made
of prototype of a pick and place robot which is used in beverages manufacturing
industries.
We have
studied and analysed and made this robot. The purpose of pick and place robot
is to pick the object which is in production line and place in the desired
place or place according to destination.
INTRODUCTION
Robotics is a prominent component of manufacturing
automation which affects human labour at all levels, from unskilled workers to
professional engineers and manager of production. Future robots may find
applications outside of the factory in banks, restaurants, and even homes. It
is possible, likely, that robotics will become a field, like today’s computer
technology, which is pervasive throughout our Society.
Well it is a system that contains sensors, control
systems, manipulators, power supplies and software all working together to
perform a task. Designing, building, programming and testing a robot is a
combination of physics, mechanical engineering, electrical engineering,
structural engineering, mathematics and computing. In some cases biology,
medicine, chemistry might also be involved. The study of robotics means that
students are actively engaged with all of these disciplines in a deeply
problem-posing problem
Robot can be
defined as programmable multi-functional manipulator. It is used to move or
hold work pieces or specialized devices and it can able to perform verity of
tasks
The use of robots is necessary to meet production
demands. There are many advantages to incorporating robots such as, decreasing
cost and waste material while speeding production. Robots are also removing the
risks to employees by performing dangerous tasks.
Since the first
industrial machine-tending robot was introduced in North
America in the 1960s, the industry has grown to more than 135,000
robots in operation, according to figures from the Robotic Industries Association
(RIA).
INTELLIGENT ROBOT’S
These are very
advanced state of robot and posses sufficient artificial and machine
intelligence. Somewhat analogous to the sensory perception of the neuromuscular
co-ordination that human being of capable of intelligent robots cannot only
explore the environment on their own perceptions and evaluate them in real
time. But also execute the necessary motor functions Match the action of the
sensor inputs. Advance robots have been built with mobility to not only move
over flour but also to climb. Compactly assemble with no board sensors,
instruments and power supplies.
INTELLIGENCE
LEVEL
- The
intelligent control robot is capable of performing some of the functions
and tasks carried out by human beings.
- It
can detect changes in the work environment by means of sensory perception.
- Intelligent
robot is equipped with a variety of sensors and sensor apparatus providing
visual (computer vision) and tactile (touching) capabilities to respond
instantly to variable situations.
- Much
like humans, the robot observes and evaluates the immediate environment by
perception and pattern recognition.
- Extensive research has been and still
concerned with how to equip robots with seeing “eyes” and tactile
“fingers”.
- Artificial intelligence (ai) that will enable the robots to respond, adapt, reason, and make decisions to react to change is also an inherent capability of the intelligent robot.
HISTORY:
1922: Rossum’sUniversalRobots
1922: Rossum’sUniversalRobots
1954: First programmable robot
1978: First PUMA robot
1983: Started teaching in
Robotics
In the early 1800’s
mechanical puppets were first built in Europe
The first industrial robots were Unimates developed by
George Devol and Joe Engelberger in the late 50’s and early 60’s. The first
patents we by Devol but Engelberger formed Unimation which was the first market
robots. So Engelberger has been called the “father of robotics”. For a
while the economic viability of these robots proved disastrous and thing slowed
down for robotics. But the industry recovered and by the mid-80’s robotics was back
on track.
George DevolJr, in 1954 developed the multijointed
artificial arm which leads to the modern robots. But mechanical engineer Victor
Scheinman, developed the truly flexible arm know as the Programmable Universal
Manipulation Arm (PUMA).
BASIC ELEMENTS OF ROBOT:
The main
parts of robot are
Ø Manipulator
Ø Controller
Ø Sensors
Ø End
effectors
Ø Power
Source
MANIPULATOR:
It consists of
base, arm and wrist similar to a human arm. It also includes power source
either electric, hydraulic or pneumatic on receiving signals from robot this
mechanical unit will be activated. The movement of manipulator can be in
relation to its coordinates system which may be Cartesian, cylindrical etc.
depending on the controller, the movements may be point to point motion or
continuous motion.
CONTROLLER:
The instructions
(programme) to the robot to perform the desired tasks are input through the key
board of this unit. A teach pendant is also provided for giving non-textual
commands input. The controller converts the input program to suitable signals
which activate the manipulator to perform the desired tasks.
SENSORS:
For certain robot
applications, the type of workstation control using interlocks is not adequate.
The robot must take on more human like senses and capabilities in order to
perform the task in satisfactory way. These senses and capabilities include
vision and hand-eye coordination, touch and hearing.
END
EFFECTOR:
The end effector is
the special-purpose tooling which enables the robot to perform a particular
job. In the terminology of robotics, an end effector can be defined as a device
which is attached to the robot’s wrist to perform a specific task. The task may
be work part handling, spot welding, spray painting, or any of a great variety
of other functions.
For purpose of
organization, we will divide the various types of end effectors into two
categories: grippers and tools.
POWER
SOURCES
·
The Three Power Sources Used In Current Robots Are:
·
Electric: All Robots Use Electricity as the Primary Source of Energy.
·
Electricity Turns The Pumps That Provide Hydraulic And Pneumatic
Pressure.
§
It Also Powers The Robot Controller And All The Electronic Components And
Peripheral Devices.
§
In All Electric Robots, The Drive Actuators, As Well As The Controller,
Are Electrically Powered.
§
Because Electric Robot Do Not Require A Hydraulic Power Unit, They
Conserve Floor Space And Decrease Factory Noise.
§
No Energy Conversion Is Required.
§
Pneumatic: These Are Generally Found In
Relatively Low-Cost Manipulators with Low Load Carrying Capacity.
§
Pneumatic Drives Have Been Used For Many
Years For Powering Simple Stop-To-Stop Motions.
§
It Is Inherently Light Weight, Particularly When Operating Pressures Are
Moderate.
§
Hydraulic: Are either Linear Position
Actuators or a Rotary Vane Configuration.
§
Hydraulic Actuators Provide A Large Amount Of
Power For A Given Actuator.
§
The High Power-To-Weight
Ratio Makes The Hydraulic Actuator An Attractive Choice For Moving Moderate To
High Loads At Reasonable Speeds And Moderate Noise Level.
§
Hydraulic
Motors Usually Provide A More Efficient Way Of Energy To Achieve A Better
Performance, But They Are Expensive And Generally Less Accurate.
CLASSIFICATION OF ROBOTS:
Robots are
classified as:
ACCORDING TO TYPE OF CONTROL:
Ø Point-to-Point
Robots
Ø Continuous
Point Robots
Ø Computed
trajectory robots and
Ø Servo-controlled
Robots.
POINT TO POINT ROBOT:
Robots move from one point to
another but cannot stop middle or intermediate position
THE CONTINOUS PATH ROBOT:
The type of robots can move
to a prescribed numbers of points along the same path and can stop at required
position
COMPUTED TRAJECTORY ROBOTS:
These types of robots can
move in a path of a specified direction.
SERVO CONTROLLED ROBOTS:
These robots have some
means of sensing the current position and it can send to prescribed or required
position
ACCORDING TO CAPABILITIES:
Ø Sequence
controlled robot’s
Ø Adaptive
robot’s
Ø Intelligent
robot’s
SEQUENCE CONTROLLED ROBOT’S:
These are operated with a
fixed sequence of actions according to the instructions.
ADAPTIVE
ROBOT’S:
They can reach according to
environment using this sensor’s the performance is optimized by adjusting
controls to changing the parameters.
INTELLIGENT ROBOT’S:
These are very
advanced state of robot and posses sufficient artificial and machine
intelligence. Some what analogous to the sensory perception of the
neuromuscular co-ordination that human being of capable of intelligent robots
cannot only explore the environment on their own perceptions and evaluate them
in real time. But also execute the necessary motor functions Match the action
of the sensor inputs. Advance robots have been built with mobility to not only
move over flour but also to clime. Compactly assemble with no board sensors,
instruments and power supplies.
ACCORDING TO THE CONFIGURATIONS:
A large numbers of
combinations are possible to design a robot for example; a robot manipulator
having 3 degree of freedom can be designed by using different combinations of
steps of joint (5X5X5) 125 ways. Further variations are possible when we
consider the sizes fourths variations are possible when we consider the sizes
ranges of motion, orientation, etc.
There are
five commonly used configurations
ü Cartesian
ü Cylindrical
ü Polar
ü Jointed arm
CARTESIAN CO-ORDINATE ROBOTIC ARM:
Axes in the robot arm are perpendicular. One axe is
part of a pole, while the other axe is a telescoping arm. One of the two parts
of the arm is attached to a base, which the robot arm can rotate on. This part
of the arm is long and thin. The other robot arm wraps around the long and thin
robot arm and can rotate around it. This allows the robot arm to rotate around
the base in order to grab something in any direction. The robot arm has the
ability to telescope, allowing it to reach out and interact with other objects.
CYLINDRICAL CO-ORDINATE ROBOTIC ARM:
This arm has a cylinder that is attached to a base.
This cylinder revolves on the base, allowing the robot arm to interact with
objects in all directions. This robot arm has a long metal shaft which is
connected to the cylinder and another long metal shaft by elbows that are
capable of bending via the internal mechanisms of gears or screwjacks. For the
other long metal shaft, one end is attached to the previous metal shaft, while
the other end is attached to a wrist that is capable of rotating. The rotating
functions are controlled with a rack and pinion system. The rack and pinion is
operated by a long, grooved strip and a grooved gear. The long grooved strip
moves in one direction or another, turning the gear via the friction caused by
the grooves on the gear and strip.
POLAR ROBOT ARM:
This robot arm has two pivotal joints, consisting of
rings turning on pivots. There is one prismatic joint which consists of one
rectangular object sliding within a larger rectangular object. All of this is
encased in a sphere which the robot arm is attached to. The two rotary joints
are perpendicular, allowing the robot arm to rotate to the left and right and
also rotate up and down. The prismatic joint allows the arm to stretch out and
interact with objects.
JOINT ROBOT ARM
The joints on this arm have a Z-shape with axes on
both ends. There is a pivotal joint on both ends of this Z-shaped arm and one
pivotal joint in the middle. The bottom part of the SCARA arm is attached to a
pedestal, which attaches to the rest of the robot.
DEGREES OF
FREEDOM
- The
Degree Of Freedom Or Grip Of A Robotic System Can Be Compared To The Way
In Which The Human Body Moves.
- For
Each Degree Of Freedom A Joint Is Required.
- The
Degrees Of Freedom Located In The Arm Define The Configuration.
- Each
of the Five Basic Motion Configurations Discuss Previously Utilizes Three
Degrees of Freedom in the Arm.
- Three
Degrees Of Freedom Located In The Wrist Give The End Effector All The
Flexibility.
- A
Total of Six Degrees Of Freedom Is Needed to Locate a Robot’s Hand at Any
Point in Its Work Space.
- Although
Six Degrees Of Freedom Are Needed For Maximum Flexibility, Most Robot
Employee Only Three To Five Degrees Of Freedom.
- The More The Degrees Of Freedom, The Greater Is The Complexity Of Motions Encountered.
Degrees Of Freedom
- The
Three Degrees Of Freedom Located In The Arm Of A Robotic System Are:
v
The Rotational Reverse: Is
The Movement of the Arm Assembly about a Rotary Axis, Such As Left-And-Right
Swivel of the Robot’s Arm about a Base.
v
The Radial Traverse: Is The
Extension And Retraction Of The Arm Or The In-And-Out Motion Relative To The
Base.
v
The Vertical Traverse:
Provides The Up-And-Down Motion Of The Arm Of The Robotic System.
- The Three Degrees Of
Freedom Located In The Wrist, Which Bear The Names Of Aeronautical Terms,
Are
- Pitch Or
- Yaw: Is The
Right-And-Left Movement Of The Wrist.
- Roll Or Swivel: Is The Rotation Of The Hand.
PATH
CONTROL
- Commercially
Available Industrial Robots Can Be Classified Into Four Categories
According To The Path Control System.
- Limited-Sequence:
Do Not Use Servo-Control To Indicate Relative Positions Of The Joints.
- They
Are Controlled By Setting Limit Switches And/Or Mechanical Stops
Together With A Sequencer To Coordinate And Time The Actuation Of The
Joints.
- With
This Method Of Control, The Individual Joints Can Only Be Moved To Their
Extreme Limits Of Travel.
- Point-To-Point:
These Robots Are Most Common And Can Move From One Specified Point To
Another But Cannot Stop At Arbitrary Points Not Previously Designated.
- Controlled
Path: Is A Specialized Control Method That Is A Part Of General Category
Of A Point-To-Point Robot But With More Precise Control.
- The
Controlled Path Robot Ensures That The Robot Will Describe The Right
Segment Between Two Taught Points.
- Controlled-Path Is A
Calculated Method And Is Desired When The Manipulator Must Move In The
Perfect Path Motion.
- Continuous
Path: Is An Extension Of The Point-To-Point Method. This Involves The
Utilization Of More Points And Its Path Can Be Arc,
- Because Of The Large Number Of Points, The Robot Is Capable Of Producing Smooth Movements That Give The Appearance Of Continuous Or Contour Movement.
ROBOT SPECIFICATION:
ACCURACY: How close does the robot get to the desired
point? When the robot's program instruct the robot to move to a specified
point, it does not actually perform as per specified. The accuracy measures
such variance. That is, the distance between the specified position that a
robot is trying to achieve (programming point), and the actual X, Y and Z
resultant position of the robot end effector.
Repeatability: The ability of a robot to return
repeatedly to a given position. It is the ability of a robotic system or
mechanism to repeat the same motion or achieve the same position. Repeatability
is a measure of the error or variability when repeatedly reaching for a single
position. Repeatability is often smaller than accuracy.
Degree of Freedom (DOF): Each joint
or axis on the robot introduces a degree of freedom. Each DOF can be a slider,
rotary, or other type of actuator. The number of DOF that a manipulator
possesses thus is the number of independent ways in which a robot arm can move.
Industrial robots typically have 5 or 6 degrees of freedom.
Resolution: The smallest increment of motion or distance that can be
detected or controlled by the robotic control system. It is a function of
encoder pulses per revolution and drive (e.g. reduction gear) ratio. And it is
dependent on the distance between the tool center point and the joint axis.
Envelope: A three-dimensional shape that defines the boundaries
that the robot manipulator can reach; also known as reach envelope.
Maximum
envelope: the envelope that encompasses the maximum designed movements of all
robot parts, including the end effector, work piece and attachments. Restricted
envelope: it is that portion of the maximum envelope which a robot is
restricted by limiting devices. Operating
envelope: it is the restricted envelope that is used by the robot while
performing its programmed motions.
Reach: The maximum horizontal distance from the center of
the robot base to the end of its wrist.
Maximum Speed: A robot moving at full extension
with all joints moving simultaneously in complimentary directions at full
speed. The maximum speed is the theoretical values which does not consider
under loading condition...
Payload: The maximum payload is the amount of weight carried
by the robot manipulator at reduced speed while maintaining rated precision.
Nominal payload is measured at maximum speed while maintaining rated precision.
These ratings are highly dependent on the size and shape of the payload due to
variation in inertia.
USE OF ROBOTS IN INDUSTRY:
Today most
robots used are found in factories and they are referred to as industrial
robots. Ten years
ago, 9 out of 10 robots were being bought by auto companies - now, less than
50% of robots are bought by car manufacturers. Robots are
used in warehouses, laboratories, research, energy plants, hospitals, space
exploration etc… Robots are
a way business owners can be more competitive Cutting
Operations Part
inspection, sorting, cleaning, polishing
PICK AND PLACE ROBOT:
In this highly developing society; time and man power are
critical constrains for completion of task in large scales. The automation is
playing important role to save human efforts in most of the regular and
frequently carried works e.g. most of the industrial jobs like welding,
painting, assembly, container filling etc. one of the major and most commonly
performed work is picking and placing of jobs from source to destination. For
this purpose, ‘pick and place robot ‘maybe used.
Pick and place systems are designed to perform repetitive
picking and placing tasks in production or laboratory facilities, and are
usually employed for their precision and cost effectiveness. McClellan Automation has the capability to
design and build custom pick and place equipment to your specifications. Pick and place machines designed by our
automation engineers are distinguished by their exceptional efficiency and
precision, resulting in an increase in output as well as long-term savings for
our Customers.
DESCRIPTION:
We
have made proto type of pick and place robotic arm which is used in beverage
industries
The
main parts of a proto type pick and place robot:
1)
Remote controller
2)
MCU circuit
3)
Robotic arm
REMOTE
CONTROLLER:-
It
consists of a transmitter and toggle switches. Here we have used encoder in
transmitter to transmits the signals to receiver part by using re communication
MCU CIRCUIT BOARD:-
It
consists of MCU, step down transformer, receiver, regulator, relay module.
We are using
8051 32bit micro controller an embedded c language program is dumped in micro
controller to control the RF communication signals.
We are
using the step down transformer to convert the 230volts to 18volts but the
circuit requires 5volts so a regulator is used to convert the 18v to 5v.
RECIEVER
Receiver
consists of decoder receives signals from the remote controller by RF
communication.
RELAY
MODULE
It
consists of 2 relays each relay consists of 1 led and overall module consists
of 3 leds and the third led is always “on”
ROBOTIC ARM
The robotic arm is
connected to micro controller unit (mcu) circuit board. The robotic arm can
cover distance within 12inches. It consists of 5 motors these 5 motors are
controlled by operating of remote control the 5 motors used in robotic arm are
One
motor is used for base rotation of 260degrees.
Second
motor is used for the shoulder movement with an angle of 160degrees.
Third
motor is used for elbow movement with an angle of 240degrees.
Fourth
motor is used for wrist movement with an angle of 120degrees.
Fifth
motor is used for gripper movement opens with a width of 1.7inches.
In
robotic arm gripper plays vital role in picking the objects. So we are going to
discuss about gripper
GRIPPERS:
Grippers are end effectors used to
grasp and hold objects. The objects are generally work parts that are to be
moved by the robot. These part-handling applications include machine loading
and unloading, picking parts from a conveyer, and arranging parts on to a
pallet. We tend to think of grippers as mechanical grasping devices, but there
are alternative ways for holding objects involving the use of magnets, suction
cups, or other means.
Grippers can be classified as single grippers or double grippers
although this classification applies best to mechanical grippers. The single
gripper is distinguished by the fact that only one grasping device is mounted
on the robot’s wrist. A double gripper has two grasping devices attached to the
wrist and is used top handle two separate objects. The two grasping devices can
be actuated independently. The double gripper is especially useful in machine
loading and unloading applications. With a single gripper, the robot would have
to unload the finish part before picking up the raw part. This would consume
valuable time in the production cycle because the machine would have to remain
open during these handling motions.
Another way of classifying depends on whether the part is
grasped on its exterior surface or its internal surface. The first type is
called external gripper and second type is referred to as an internal gripper.
The reason for using a gripper instead of attaching the
tool directly to the robot’s wrist is typically because the job requires
several tools to be manipulated by the robot during the work cycle. The gripper
serves as a quick change device to provide the capability for a rapid
changeover from one tool to the next.
In addition to end effectors, other types of fixturing
and tooling are required in many industrial robot applications. These include
holding fixtures, welding fixtures, and other forms of holding devices to
position the work part or tooling during work cycle grippers.
WORKING OF PICK AND PLACE
ROBOTIC ARM
When
power is supplied from power source to transformer (step down) the input is
230volts and its output is 18volts. But 5volts is enough to run the circuit so
regulator is used to decrease the voltage from 18volts to 5volts.
If
power is supplied to remote control by 9volts battery then the leds on each
switch board will turn “on” and the leds on receiver turn “off”. It indicates
that the signals have been reached from transmitter to receiver.
If any fault is there in remote control
circuit the respective relay leds will turn “on” on relay module
When
any switch is pressed on switch board the receiver receives signals from
transmitter on remote control. Now the signals from the receiver sent to micro
controller unit. The micro controller receives signals from receiver and read the
programme and gives the instructions to relays. According to the instructions
the relays will control the motors of robot arm.
In
proto-type robotic arm it consists of 5 different types of movements which are
operated by switches in remote controller
This
has 3 switch boards namely SB1, SB2 and SB3 (from right)
Switch board 1(SB1)
The
first board consists of 4 switches which controls gripper and wrist. the Gripper movements opened and closed are
carried out by G1 and G2 switches.
G1→Opening
G2→Closing
The wrist movements up and down carried out by W1 and
W2 switches.
W1→Down
W2→Up
Switch
board 2(SB2)
The SB2 consists of 4 switches which control
shoulder and elbow.
The shoulder movements are operated
by S1 and S2 switches
S1→Down
S2→Up
The elbow
movements operated by E1 and E2 switches
E1→Up
E2→Down
Switch
board 3 (SB3)
SB3 consists of 4 switches which
controls base and light.
The base movements are operated by
B1→Clockwise
B2→Anticlockwise
The light ON/OFF controlled by
L1→-----
L2→ON/OFF
ADVANTAGES:
They
include higher productivity reduced
labour costs reduced
downtime increased
quality and consistency and inventory
and scrap savings In addition
the same robot can potentially be used for a variety of tasks
DIS ADVANTAGES:
Reprogramming
the controller and replacing fixturing in the work cell and the end-effectors
this can be expensive and time consuming. The single
most prohibitive aspect of using robotic automation is the initial investment
required in purchasing the robot itself.
CHARACTERISTICS GENERAL APPLICATION
There are
certain general characteristics of an industrial situation which tends to make
the installation of a robot economical and practical. These general
characteristics include the following
Hazardous
or un-comfortable working conditions:
In job
situations where there are potential dangers or health hazards due to heat,
radiation, or toxicity, or where the workplace is uncomfortable and unpleasant,
a robot should be considered as a substitute for the human worker.
Repetitive tasks:
If the work
cycle consists of a sequence of elements which do not vary from cycle to cycle.
It is possible that a robot could be programmed to perform the task.
Difficult handling:
If the work
part or tool involved in the operation is awkward or heavy, it might be
possible for a robot to perform the task.
Multi shift operation:
If the initial
investment cost of the robot can be spread over two or three shifts, the labour
savings will result in a quicker payback.
APPLICATION AREAS:
•
Material
transfer.
•
Machine
loading.
•
Welding.
•
Spray
coating.
•
Processing
operation.
•
Assembly.
•
Inspection.
BIBLIOGRAPHY.
McGraw-Hill INTERNATIONAL EDITION, industrial engineering series,
industrial robotics, MIKELL P.GROOVER, MITCHELL WEISS, ROGER N.NAGEL, NICHOLAS
G.ODREY
PRENTICE HALL OF INDIA PRIVATE LIMITED, New delhi-110001, 1994. MIKELL P.GROOVER,
EMORY W.ZIMMERS, JR.
J.F. ENGLEBERGER, ROBOTICS IN
PRACTICE, AMACOM (AMERICAN MANAGEMENT ASSOCIATION), NEW YORK
R. HINSON,”CASE STUDY: ROBOTS IN
MACHINE LOAD/UNLOAD OPERATIONS,”
CONCLUSION:
This
robot is used for pick the object in one place and place that objects in
required places.
Some
industrial works are harmful for humans this robot is mainly used for reduce
the risk process and consuming time and avoid labours. Human are tired for hard
work such as assembly line, material handling etc. this robot does all those
things it mainly reduces the manual work our robot is designed
At
low cost as well as high efficient one.
This
project is to give the way for providing bigger effective robot for
Industrial
applications.
