1.ch01_TS_L1_L2.pdf

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

The Production System

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

Manual Work System

Worker-Machine System

Automated System

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

Information Processing Cycle in

Manufacturing Support Systems

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)

Computer Integrated Manufacturing

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

Product Variety and Production

Quantity for Three Automation Types

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

Automation

Migration

Strategy

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.