At the endof the class, student should be able to:-
1.0 INTRODUCTION AND BASIC CONCEPT
OF AUTOMATION
1.1 Describe the concept of industrial
automation.
1.1.1 Definition of industrial
automation.
1.1.2 State the advantages and
disadvantages.
1.1.3 Identify types of automation.
1.1.4 Describe the Automation in
production system.
1.2 Explain the basic concept of robot
terminology.
1.2.1 Describe the basic concept
following:
a. Link and Joint
b. Degree of Freedom (dof)
c. Orientation Axes
d. Position Axes
e. Tool Centre Point (TCP)
f. Work envelope/workspace
g. Speed
h. Payload
i. Repeatability
j. Accuracy
k. Settling Time
l. Control Resolution
m. Coordinates
• Definition Industry:
SystematicEconomic Activity that could
be related to Manufacture/Service/
Trade.
• Definition Industrial Automation:
Automation is a set of technologies
that results in operation of machines
and systems without significant human
intervention and achieves performance
superior to manual operation
5.
Advantages for Automation
1.To increase labor productivity. Automating a manufacturing operation usually
increases production rate and labor productivity. This means greater output per hour of
labor input.
2. To reduce labor cost. Ever-increasing tabor cost has been and continues to be the
trend in the world's industrialized societies. Consequently, higher investment in
automation has become economically justifiable to replace manual operations.
Machines are increasingly being substituted for human lahar to reduce unit product
cost.
3. To migrate the effects of labor shortages. There is a general shortage of labor in
many advanced nations and this has stimulated the development of automated
operations as a substitute tor labor.
6.
Advantages for Automation
4.To reduce or eliminate routine manual and clerical tasks. An argument
can be put forth that there is social value in automating operations that are
routine, boring, fatiguing, and possibly irksome. Automating such tasks
serves a purpose of improving the general level of working conditions.
5. To improve worker safety. By automating a given operation and
transferring the worker from active participation in the process to a
supervisory role, the work is made safer. The safety and physical well-being
of the worker has become a national objective with the' enactment of the
Occupational Safety and Health Act (OSHA) in 1970. This has provided an
impetus for automation.
7.
Advantages for Automation
6.To improve product quality. Automation not only results in higher production
rates than manual operations; it also performs the manufacturing process with
greater uniform and conformity to quality specifications. Reduction attraction
defect rate is one of the chief benefits of automation.
7. To reduce manufacturing lead time. Automation helps to reduce the elapsed
time between customer order and product delivery, providing a competitive
advantage 10 the manufacturer for future orders. By reducing manufacturing lead
time, the manufacturer also reduces work-in-process inventory.
8.
Advantages for Automation
8.To accomplish processes that cannot be done manually. Certain operations cannot be accomplished without the aid
of a machine. These processes have requirements for precision, miniaturization or complexity of geometry that
cannot be achieved manually.
Examples include certain integrated circuit fabrication operations, rapid prototyping processes based on computer
graphics (CAD) models, and the machining of complex, mathematically defined surfaces using computer numerical
control. These processes can only be realized by computer controlled systems.
9. To avoid the high cost of not automating. There is a significant competitive advantage gained in automating a
manufacturing plant. The advantage cannot easily be demonstrated on a company's project authorization form. The
benefits of automation often show up in unexpected and intangible ways, such as in improved quality, higher sales,
better labor relations, and better company image. Companies that do not automate are likely to find themselves at a
competitive disadvantage with their customers, their employees, and the general public
9.
Disadvantages of Automation
1.Higher Start-up cost and the cost of operation. Automated
equipment includes the high capital expenditure required to invest in
automation. An automated system can cost millions of dollars to design,
fabricate, and install.
2. Higher Cost of Maintenance. A higher level of maintenance needed
than with a manually operated machine. These include buying
electromechanical devices such as electromechanically valve, sensory
devices, and smart devices. Cost of spare parts for automation system
may consider higher compare to the manual operate.
10.
Disadvantages of Automation
•Obsolescence/Depreciation Cost. Obsolescence and depreciation is a gradual
reduction in the value of physical assets. This phenomenon is characteristic of all
physical assets in the form of equipment and machinery. It was something that was
inevitable due to technology development. Obsolescence or depreciation can be
classified into two parts, namely: -
i. Physical Depreciation - occurred as a result of physical damage of equipment or
robots. It describes a form that can be seen clearly as damage, wear and corrosion.
ii. Depreciation of the functions - it existed from changes in demand for services may
be provided. Depreciation caused by changes in the need for an equipment service
discovery of new equipment or a robot system inability to meet demand
11.
Disadvantages of Automation
4.Unemployment. A disadvantage often associated with automation, is
worker displacement. Due to the fact that manual laborers are being
replaced by robots or other automated machineries, this results to mass
lay-off. A lot of people are losing their jobs especially those who work in the
manufacturing industry such as a car factory.
5. Not economically justifiable for small scale production.
12.
Types of Automation
System
Automatedmanufacturing systems
can be classified into three basic
types:
i. Fixed automation.
ii. Programmable
automation, and
iii. Flexible automation.
13.
Fixed Automation
Fixed/hard automationis designed for large volume
production of a single product or task. The machine
layout is designed to the fixed sequence of operations.
Pros—
• Typically, lower build costs compared to programmable and
flexible options.
• Improved product consistency
• Operates at high speed for a high production rate
• Lower unit cost for each piece sold
Cons—
• Machine layout inflexible, so alterations to design are costly
and time-consuming
14.
Hard
automation
• Examples offixed automation include machining
transfer lines found in the automotive industry,
automatic assembly machines, and certain
chemical processes.
• This is relatively useful for many companies who
use automation to create food products of one
type and variant. It allows them to effectively
produce that item and package it in bulk.
• Foods that require chemical processes, for
example, may use this to ensure the consistency
of the chemical processes.
15.
Programma
ble
Automation
• Programmable automationallows the production
equipment and automation to be altered to changing
needs. This is done by controlling the automation through a
program, which can be coded in certain ways for the
automation to change the sequence of automation.
• It’s used more commonly in low to medium levels of
production, often being most suitable for batch production.
• Programmable automation will often be used by factories
who make different variants of foods. This allows them to
make batches, from a few dozen to potentially thousands at
a time, of one product. If the product needs changing, it
simply needs to be reprogrammed.
• Advantages include:
Flexibility to change products if needed
Suitable if batch production is required
Disadvantages include:
Expensive for equipment
Lower production levels
Often time-consuming to change products
This type of automation is well suited for: Low/Medium
demand and occasional changes in products.
16.
Programmable automation iffor the
manufacturer that needs flexibility in
production for batch runs.
Programmable machinery allows for
the reprogramming of sequences
which will allow for different product
configurations.
Pros—
• Flexible system
• Suitable for batch runs from 50 to 1000
unit
Cons—
• Re-configuring the system can still be
time-consuming.
• This system requires an upfront
substantial investment for general
purpose programmable equipment.
17.
Flexible
Automation
Flexible/soft automation isan extension of
programmable automation, but with less time
lost for reprogramming or tool changes. This
automation is for the manufacturer that needs to
run a variety of products with no downtime
between batches.
Pros—
• Continuous production includes in sequence product
variables
• Medium production
Cons—
• Higher initial investment than fixed or programmable
• Components that allow for quick changes, such as a
robot arm, will need logic controllers, sensors and lasers.
• Skilled labor for part changes, maintenance, and other
supervisory duties.
18.
Three types ofautomation relative to production quantity and product variety.
19.
Describe the Automationin Production System
Production System consists of facilities and manufacturing support systems
A production system is a collection of people, equipment, and procedures organized to perform the
manufacturing operations of an organization. A production system consists of facilities and manufacturing
support systems (Figure 1.5):
i. Facilities—the factory, the equipment in the factory, and the way the equipment is organized around the
shop floor.
ii. Manufacturing support systems—the set of procedures used to manage production and to solve
technical and logistics problems met in manufacturing processes. These systems include product design,
planning and control, logistics and other business functions.
22.
Basic Concept ofAutomation Terminology
• Links and Joints
• Links are the solid structural members of a robot, and joints are the movable
couplings between them. Joints or axes found in the manipulator (robotic
arm). A joint of an industrial robot (Figure 1.10) is similar to a joint in the
human body. It provides relative motion between two parts of the body.
Joints consists of two types, major axis comprising the base, shoulder and
elbow and minor axis comprising wrist pitch, wrist roll and wrist yaw.
25.
Degree of freedom(DOF)
• Each joint on the robot introduces a degree of freedom. Each dof can
be a slider, rotary, or other type of actuator.
• Robots typically have 5 or 6 degrees of freedom. 3 of the degrees of
freedom allow positioning in 3D space, while the other 2or 3 are used
for orientation of the end effector.
• 6 degrees of freedom are enough to allow the robot to reach all
positions and orientations in 3D space.
• 5 dof requires a restriction to 2D space, or else it limits orientations.
• 5 dof robots are commonly used for handling tools such as arc
welders.
26.
Each joint representsa degree of
freedom; there are 22 joints and
thus 22 degree of freedom in the
human hand
28.
• From theFigure 1.13 we can see that the robot has five degrees of
freedom. That means we can have it move in five independent ways.
The five different movements are created in five different joints as
described below.
1. Base Joint: This joint allows movement of 350° rotational motion.
2. Shoulder Joint: This joint allows movement of 120° rotational motion.
3. Elbow Joint: This joint allows movement of 135° rotational motion.
4. Wrist Joint: This joint allows movement of 340° rotational motion.
5. Gripper: This joint allows movement of 2 linear motions (open and close
actions).
29.
Orientation Axes
• ifthe tool is held at a fixed position, the orientation determines which
direction it can be pointed in.
• Roll, pitch and yaw are the common orientation axes used. Looking at
the figure below it will be obvious that the tool can be positioned at
any orientation in space.
• (Imagine sitting in a plane. If the plane rolls you will turn upside
down. The pitch changes for takeoff and landing and when flying in a
crosswind the plane will yaw.)
31.
Position Axes
• Thetool, regardless of orientation, can be moved to a number of
positions in space.
• Various robot geometries are suited to different work geometries.
(more later) The definition of an object's location in 3-D space, usually
defined by a 3-D coordinate system using X, Y, and Z coordinates.
• Part of a robot can move to a spot within its work envelope, using
devices that tell it exactly where it is. Translatory degrees of freedom.
32.
Tool Centre Point(TCP)
• The tool center point is located either on the robot, or the tool.
Typically the TCP is used when referring to the robots position, as well
as the focal point of the tool. (e.g. the TCP could be at the tip of a
welding torch) The TCP can be specified in Cartesian, cylindrical,
spherical, etc. coordinates depending on the robot.
• As tools are changed we will often reprogram the robot for the TCP.
• Tool midpoint is the reference point of tools controlled by the robot.
34.
Work envelope/workspace
• Workenvelope is the volume/area where the robotic arm can
perform task/work .
• The space in which a robot can operate is its work envelope, which
encloses its workspace.
• While the workspace of the robot defines positions and orientations
that it can achieve to accomplish a task, the work envelope also
includes the volume of space the robot itself occupies as it moves.
36.
Speed
• Speed isthe rate of movement from point to point done by robots
under the control of the program.
• It is a measure of the speed of the device.
37.
Payload
• The payloadindicates the maximum mass the robot can lift before
either failure of the robots, or dramatic loss of accuracy.
38.
Repeatability
• The degreeability of a robotic arm to detect targets has been set
correctly and then returns to its original point in the work cell.
• The robot has a high repeatability will be able to repeat the task with
the right repeatedly without error.
39.
Accuracy
• The degreeof ability that can be made by a robotic arm to move to a
certain point in the work cell as we enter the coordinates in the off-
line programming station (off-line programming).
40.
Settling Time
• Thesettling time is the time required for the robot to be within a
given distance from the final position.
• During a movement, the robot moves fast, but as the robot
approaches the final position is slows down, and slowly approaches.
• The time-instant when the actual output converges to the desired
output is known as the settling time.
41.
Control Resolution
• Capabilityof robot's positioning system to divide the motion range of
each joint into closely spaced points.
• This is the smallest change that can be measured by the feedback
sensors, or caused by the actuators, whichever is larger. If a rotary
joint has an encoder that measures every 0.01 degree of rotation, and
a direct drive servo motor is used to drive the joint, with a resolution
of 0.5 degrees, then the control resolution is about 0.5 degrees (the
worst case can be 0.5+0.01).
42.
Coordinates
• combination ofboth the position of the origin and orientation of the
axes.
• Points are programmed in the cells identified job position by using the
values of the coordinates x, y and z of the tools midpoint and
extension angles at the wrist axis robot arm is pitch, roll and yaw.