chapter2-automation system in industry

Chapter 2

Automation System in Industry

ESE616 Industrial Automation &

Robotic

Main source: Mikell P. Groover,

Automation, Production Systems, and

Computer-Integrated Manufacturing

Video source: Youtube

Types of Operation Automation system in industry operated on the physical product, example:

Automated machine tools that process parts

Use energy such as mechanical, thermal, electrical, and chemical to alter

a workparts shape, physical properties, or appearance.

include the process of shaping operations, property-enhancing

operations and surface processing operation.

Example:

Automated

shaping

operation (CNC

milling)

Types of Operation Transfer lines that perform a series of machining operations

Series of machining operation

Types of Operation Automated assembly systems

Example: Automated cap assembly

Types of Operation Manufacturing systems that use industrial robots to perform processing or

assembly operations

Example: USB

memory stick

assembly using

industrial robot

Types of Operation Automatic material handling and storage systems to integrate manufacturing

operations

Example: Automated

material handling

system

Types of Operation Automatic inspection systems for quality control

Physical inspection

Functionality

Type of Automation in Industry Fixed automation

Also known as hard automation, refers to an automated production facility in

which the sequence of processing operations is fixed by the equipment

configuration.

The programmed commands are contained in the machines in the form of

cams, gears, wiring, and other hardware that is not easily changed over from

one product style to another. This form of automation is characterized by high

initial investment and high production rates.

It is therefore suitable for products that are made in large volumes. Examples of

fixed automation include machining transfer lines found in the automotive

industry, automatic assembly machines, and certain chemical processes.

Type of Automation in Industry Programmable automation

Is a form of automation for producing products in batches. The products are

made in batch quantities ranging from several dozen to several thousand units at

a time. For each new batch, the production equipment must be reprogrammed

and changed over to accommodate the new product style.

This reprogramming and changeover take time to accomplish, and there is a

period of nonproductive time followed by a production run for each new batch.

Production rates in programmable automation are generally lower than in fixed

automation, because the equipment is designed to facilitate product changeover

rather than for product specialization.

A numerical-control machine tool is a good example of programmable

automation. The program is coded in computer memory for each different

product style, and the machine tool is controlled by the computer program.

Industrial robots are another example.

Type of Automation in Industry Flexible automation

Is an extension of programmable automation. The disadvantage with

programmable automation is the time required to reprogram and change over

the production equipment for each batch of new product. This is lost

production time, which is expensive.

In flexible automation, the variety of products is sufficiently limited so that the

changeover of the equipment can be done very quickly and automatically.

The reprogramming of the equipment in flexible automation is done off-line;

that is, the programming is accomplished at a computer terminal without using

the production equipment itself. Accordingly, there is no need to group

identical products into batches; instead, a mixture of different products can be

produced one right after another.

Automated Assembly System Automated assembly refers to the use of mechanized and automated devices to

perform the various assembly tasks in an assembly line or cell.

Performs a sequence of automated assembly operations to combine multiple

components in a single entity.

Automated assembly technology should be considered when the following

Condition exists.

High product demand Millions of units (or close).

Stable product design Changing workstation tools and assembly sequence can

be costly.

The assembly consists of no more than a limited number of components

Recommends a maximum of around a dozen parts.

The product is designed for automated assembly.

Automated Assembly System

A typical automated assembly system consists of the following subsystems

One or more workstations at which the assembly steps accomplished.

Part feeding devices that deliver the individual components to the workstation.

The work handling system for the assembled entity.

Automated Assembly SystemWorkTransport System

Continuous transport systems uses a continuous moving conveyor that

operates at constant velocity. It can be implemented in two ways.

1.Work units are fixed to the conveyor or track.

2.Work units are removable for the conveyor.

Synchronous transport system All work units are moved simultaneously

between stations with a quick, discontinuous motion, and then positioned at

their respective stations.

Asynchronous transport system - a work unit leaves a given station when the

assigned task has been completed and the worker release the unit. Work units

move independently rather than synchronously. At any moment, some units are

moving between workstations, while others are positioned at stations.

Stationary base part system - the base part to which the other components are

added is placed in a fixed location, where it remains during the assembly work.

Automated Assembly System There are 4 types of automated assembly system based on the physical

configuration.

1. In-Line Consist of a series of automatic workstations located along an in-

line transfer system. Continuous, synchronous, or asynchronous transfer

systems can be used with the in-line configuration.

Automated Assembly System 2. Dial-type Base parts are loaded onto fixtures or nests attached to the circular

dial. Normally used with continuous and synchronous motion of work units.

Automated Assembly System 3. Carousel Represent a hybrid between the circular work flow of the dial

assembly machine and straight work flow of the in-line system. Asynchronous

transfer mechanism often used to move the work units.

Automated Assembly System 4. Single Station Assembly operations are performed on a base part at a single

location. The typical operation cycle involves the placement of the base part at a

stationary position in the workstation, followed by the addition of components

to the base.

Multi-station assembly machine or line

Faster cycle rate

High production quantities

More operations possible

More components per assembly

Single-station assembly cell

Suited to robotic assembly

Intended for lower production quantities

Multi-Station vs. Single-Station



A workstation accomplished on or both of the following

tasks:

A part is delivered to the assembly workhead and added to the existing base

part on front of the workhead.

A fastening or joining operation is performed at the station in which parts

added at the workstation or at the previous workstations are permanently

attached to the existing base part.


Parts Delivery System:

Hopper The container in which the components are loaded at the

workstation. A separate hopper is used for each component type and the

components are normally loaded in bulk.

Parts Feeder Removes the components for the hopper one at a time for

delivery to the assembly workhead. The hopper and parts feeder are often

combined into one operating mechanism.



Selector A selector is a device that acts as a filter, permitting only parts in the

correct orientation to pass through where incorrectly orientated parts are

rejected back into the hopper.

Orientor An orientor is a device that allows properly oriented parts to pass

through, but it reorients parts that are not properly oriented initially.



(a) Selector, (b) Orientor



Example: Automated parts delivery



Feed track A Feed track is used to move the components from the hopper and

parts feeder to the location of the assembly workhead, maintaining proper

orientation of the parts during the transfer.

Gravity type Hopper and parts feeder are located at an elevation above that of the

workhead.

Powered type uses vibrator action, air pressure, or other means to force the parts

to travel along the feed track toward the assembly workhead.

Escapement to remove components from the feed track at time intervals that are

consistent with the cycle time of the assembly workhead.

Placement device Physically places the component in the correct location at the

workstation for the assembly operation.


(a) Horizontal and (b) vertical devices for placement of parts onto dial-

indexing table

Escapement and placement

Automated Assembly System Escapement and placement

Escapement of rivet-shaped parts actuated by work carriers

Automated Assembly System Escapement and placement

Two types of pick-and-place mechanisms

for transferring base parts from feeders to

work carriers

Total Quality Management

A management approach that pursues three main objectives:1. Achieving customer satisfaction

2. Continuous improvement

3. Encouraging involvement of the entire work force

Quality is focused on customer satisfaction where productsare designed and manufactured with this quality focus.

External customers are those who buy the companysproducts.

Internal customers are manufacturing departmental insidethe company who are received (normally unfinished product)

from others manufacturing department.

In term of working support, the engineer is the customer ofthe technical staff support group.

Total Quality Management

The quality goals of a company are not established inmanufacturing, they are defined at the highest levels of

organization.

Does the company want to simply meet specifications set by thecustomer?

Or, does the company want to make products that go beyond thetechnical specifications?

Does it want to be known as the lowest price supplier or thehighest quality producer in its industry?

All the above questions will drive the quality goals of thecompany.

High product quality is a process of continuous improvement. It isa never-ending chase to design better products and then to

manufacture them better.

Quality Improvement in Automation

System

Any proper industrial automation will verify the presence andposition of a part after it has been placed into the

assembly. Often the equipment will incorporate in-process testing

to verify that the product is correct before sending it to the next

operation.

Another quality improvement is the elimination of piece partrejects. A defective or out-of-tolerance part will usually not pass

through the tooling required to automatically feed and load

it. This sorting of rejects will improve the quality of the finished

goods, but it will also put pressure on the upstream operations to

control the piece part quality.

Source: The Next Step Industrial Automation - When and What to Automate

By Tracy Witzenburg

Equipment Engineering Manager

Belcan Engineering Automation Group

Solon, OH

chapter2-automation system in industry

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