1.ch01_ts_l1_l2.pdf
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1.ch01_TS_L1_L2.pdfTRANSCRIPT
What is an Automated System???
An automated system is a collection of devices working
together to accomplish tasks or produce a product or
family of products.
EXAMPLE 1: Automatic door lock/unlock system. There is
a biometric sensor to match the fingerprint which is
connected to the control box as an input. Control box
receives the signal and acts accordingly.
EXAMPLE 2: Home burglar alarm system. Control box
receives signal (image, switch input) and activates the
alarm.
Modern Manufacturing Approaches
and Technologies
Automation - automated equipment instead of labor
Material handling technologies - because manufacturing usually involves a sequence of activities
Manufacturing systems - integration and coordination of multiple automated or manual workstations
Flexible manufacturing - to compete in the low-volume/high-mix product categories
Quality programs - to achieve the high quality expected by today's customers
CIM - to integrate design, production, and logistics
Lean production - more work with fewer resources
Production Systems
A production system is a collection of people, equipment, and procedures organized to accomplish the manufacturing operations of a company
Two categories:
Facilities – the factory, the equipment in the factory and the way the equipment is organized (plant layout)
Manufacturing support systems – the set of procedures used by a company to manage production and to solve technical and logistics problems in ordering materials, moving work through the factory, and ensuring that products meet quality standards
Production System Facilities
Facilities include the factory, production machines and
tooling, material handling equipment, inspection
equipment, and computer systems that control the
manufacturing operations
Plant layout – the way the equipment is physically
arranged in the factory
Manufacturing systems – logical groupings of
equipment and workers in the factory
Production line
Stand-alone workstation and worker
Manufacturing Systems
Three categories in terms of the human participation in the
processes performed by the manufacturing system:
1. Manual work systems - a worker performing one or
more tasks without the aid of powered tools, but
sometimes using hand tools
2. Worker-machine systems - a worker operating
powered equipment
3. Automated systems - a process performed by a
machine without direct participation of a human
Manufacturing Support Systems
Involves a cycle of information-processing activities that
consists of four functions:
1. Business functions - sales and marketing, order entry,
cost accounting, customer billing
2. Product design - research and development, design
engineering, prototype shop
3. Manufacturing planning - process planning, production
planning, Manufacturing Resource Planning (MRP),
capacity planning
4. Manufacturing control - shop floor control, inventory
control, quality control
Automation in Production Systems
Two categories of automation in the production system:
1. Automation of manufacturing systems in the
factory
2. Computerization of the manufacturing support
systems
The two categories overlap because manufacturing
support systems are connected to the factory
manufacturing systems
Computer-Integrated Manufacturing (CIM)
Automated Manufacturing Systems
Industrial automated system can be a single machine or
a group of machine often referred as cell.
Automated manufacturing systems include:
Automated machine tools
Automated Transfer lines
Automated assembly systems
Industrial robots that perform processing or
assembly operations
Automated material handling and storage systems to
integrate manufacturing operations
Automatic inspection systems for quality control
Automated Manufacturing Systems
Three basic types:
1. Fixed automation
2. Programmable automation
3. Flexible automation
Fixed Automation
A manufacturing system in which the sequence of
processing (or assembly) operations is fixed by the
equipment configuration
Typical features:
Suited to high production quantities
High initial investment for custom-engineered equipment
High production rates
Relatively inflexible in accommodating product variety
Programmable Automation
A manufacturing system designed with the capability to change the sequence of operations to accommodate different product configurations
Typical features:
High investment in general purpose equipment
Lower production rates than fixed automation
Flexibility to deal with variations and changes in product configuration
Most suitable for batch production
Physical setup and part program must be changed between jobs (batches)
Flexible Automation
An extension of programmable automation in which the
system is capable of changing over from one job to the
next with no lost time between jobs
Typical features:
High investment for custom-engineered system
Continuous production of variable mixes of products
Medium production rates
Flexibility to deal with soft product variety
Needs for automation
Increased throughput or productivity.
Improved quality. i.e accuracy
Improved robustness (consistency), of
processes or product. i.e Precision
Reduce excess labour cost
Components of automation
Robots
CNC Machines
Conveyers, palletizers [hard automation devices
with little flexibilities]
Control Devices [ PLCs, Microcontroller based]
Feedback Devices [Sensors, Vision systems]
Components of automation: ROBOT
Robots can be used for repetitive work such as
pick and place operations.
It can also be used for production work like
Welding.
Robots are very accurate and precise in repetitive
work.
Components of automation: ROBOT
Classification of Robot based on actuation mechanism
a) Electrical
Fast and accurate
Versatile operation (Positioning part, Welding etc)
But Expensive
b) Pneumatic
Fast, accurate and also inexpensive
Limited task
Low payload
c) Hydraulic
Smooth operation (good for painting)
Heavy pay load
Components of automation: CNC
Computer Numerical Control machines (CNC) are machines
whose motions are controlled by a computer. They are
programmable and they can produce wide range of parts.
Example: CNC milling machine
CNC Turning machine
CNC electro-discharge machine (EDM)
CNC wire electro-discharge machine (WEDM)
Components of automation: ASRS
ASRS => Automatic
Storage and Retrieval
Section
Used to store parts
Computer controls the
storage of the parts
It knows which place is
empty and which place
is occupied through
sensor feedback.
Components of automation: Conveyer
Conveyer used to move parts between cells.
Conveyers may equipped with sensors to know which part
is present and where it is needed to be moved. Parts are
held by pallets on a conveyor.
Components of automation: PLCs
PLCs => Programmable
Logic Controller is the
brain of the industrial
automated system.
It can be programmed by
ladder logic.
This is a robust computer
designed for industry
and easily
understandable by
electricians and
technicians.
Components of automation: Sensors
There are numerous types of sensors. Following are
some examples
1. Analog e.g capacitive pressure sensor,
temperature sensor, force sensor etc.
2. Digital sensors e.g limit switches, optical
switches, counters etc.
3. Contact sensors e.g Limit switch
(mechanical)
4. Non-contact or proximity sensor e.g Limit
switch (optical)
Components of automation: Vision system
Vision system is used to check the product quality e.g
holes on a PCB are properly positioned, components on
the PCB are all present.
Typical arrangement of the vision system is as follows
a) Image capturing by camera (digital camera e.g CCD)
b) Image acquisition to the computer.
c) Image analysis by comparison
d) Output (pass/fail)
e) Result analysis
Components of automation: Vision system
Resolution of the vision system: Based on number of pixel on
the part image.
Sensor is 8 by 8 pixels
No of Pixels (covered by the image) in X Px=3
No of Pixels in (covered by the image) in Y Py= 4.5
X
Y
Components of automation: Vision system
Diameter of the part is d= 5mm. What is the resolution is X
and Y direction?
Resolution in X direction Rx= d/Px = 5/3 = 1.67 mm
Resolution in Y direction Ry = d/Py = 5/4.5 = 1.11 mm
X
Y
Classification of Components of Automation
Automation System
Production Support Control Feedback
Devices Equipments Devices Devices
(Robot, CNCs) (Conveyor) (PLCs) (Sensors,
Vision system)
Automation Principle
1. Understand the existing process
Input/output analysis
Value chain analysis /supply chain analysis
Charting techniques and mathematical modeling
2. Simplify the process
Reduce unnecessary steps and moves
3. Automate the process
Ten strategies for automation and production
systems
Automation migration strategy
Automation Strategies
1. Specialization of operations
2. Combined operations
3. Simultaneous operations
4. Integration of operations
5. Increased flexibility
6. Improved material handling and storage
7. On-line inspection
8. Process control and optimization
9. Plant operations control
10.Computer-integrated manufacturing
Automation Migration Strategy
1. Phase 1 – Manual production
Single-station manned cells working independently
Advantages: quick to set up, low-cost tooling
2. Phase 2 – Automated production
Single-station automated cells operating
independently
As demand grows and automation can be justified
3. Phase 3 – Automated integrated production
Multi-station system with serial operations and
automated transfer of work units between stations
Cost Justification
Automation system is installed when it saves money for
the company
Before installing any new automation system company
must calculate the payback period
P = Payback period in years
C = Total cost of the system including installations
W = Annual wages of labour and fringe benefits for the
workers who are replaced
Cost Justification
I = Savings in terms of productivity, quality, materials
D = Depreciation allowance
M = System maintenance cost.
S = Additional staffing for maintenance, programming.
System Design
Start
Key in no of shafts to
be machined
Robot load another part
Robot load part for QC
Pass?
Total number
Achieved?
END
Scrap
NO
YES
NO
YES
System Design
Operator inputs no of shafts to be machined
Robotic arm load the part on a CNC lathe machine
Robot unload the part after machining and load it in a QC
station (Vision system)
The shaft diameter is measured and if it is outside the
tolerance limit the part is scrapped.
If it is within tolerance limit the finished part is counted.
Robot loads the next part until it reaches the desired
value.