Computer Integrated Manufacturing (CIM)

Computer Integrated Manufacturing (CIM) prepared by RJ

CHAPTER 1:1.0 Introduction to CIM1.1 Fundamentals of CAD/CAM1.2 Automation and Control Technologies1.3 Types of Manufacturing Systems1.4 Integration of Manufacturing Systems

UNIVERSITI TEKNOLOGI MARAFACULTY OF MECHANICAL ENGINEERING

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Computer Integrated Manufacturing (CIM) System that applies computer and

communications technology to all the operational functions and information processing functions in manufacturing from order receipt through design and production to product shipment.

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Major Applications of CIM Computer Numerical Control (CNC) Adaptive control Industrial robots Automated handling of materials Automated and robotic assembly systems Computer-aided process planning Just-in-time production Group technology Artificial intelligence

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Why Use CIM? Responsiveness to rapid changes in market

demand and product modification. Better use of materials, machinery, personnel,

reduction inventory. Better control of production and management of

the total manufacturing operation. The manufacture of high-quality products at low

cost.

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Modern Manufacturing Approaches and Technologies (Chapter 1) Automation - use of automated equipment instead of

labor to decrease labor time, cost, production cycle time, increase product quality and consistency.

Material handling technologies - because manufacturing usually involves a sequence of activities performed at different locations in the plant.

Manufacturing systems - integration and coordination of multiple automated/manual workstations/material handling technology. No independent operation of individual workstations.

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Modern Manufacturing Approaches and Technologies Flexible manufacturing - to compete in the low-

volume/high-mix product categories. Quality programs - to achieve high quality

expected by today's customers by employing techniques such as six sigma, etc.

CIM - to integrate design, production, and logistics. Technologies such as CAD, CAM & computer networks.

Lean production - more work with fewer resources.

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Production System Defined A collection of people, equipment, and

procedures organized to accomplish the manufacturing operations of a company.

Two categories/levels: Facilities – the factory and equipment in

the facility and the way the facility is organized (plant layout).

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Production System Defined 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.

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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

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Manufacturing SystemsThree 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 worker.

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Manufacturing Systems

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Manufacturing Support SystemsInvolves 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, MRP, capacity planning.4. Manufacturing control - shop floor control, inventory

control, quality control.

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Information Processing Cycle in Manufacturing Support Systems

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Automation in Production SystemsThe automated elements of the production systems are:

1. Automation of manufacturing systems in the factory.2. Computerization of the manufacturing support

systems. The two categories overlap because the automated

manufacturing systems are implemented by computer systems and connected to the computerized manufacturing support systems and management information system.

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Automated Manufacturing Systems Perform operations such as processing, assembly,

inspection & material handling. Reduced level of human participation.

Examples: automated machine tools that process parts, automatic material handling & storage systems to integrate manufacturing operations, automatic inspection system for quality control, etc.

Three basic types: (1) fixed, (2) programmable & (3) flexible automation.

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Computerized Manufacturing Support Systems Use of computer systems to design the

products, plan the production, control the operations & perform various functions.

Examples: CAD, CAM, CAD/CAM, etc. These uses computer systems to support/perform functions for product design or manufacturing engineering.

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Reasons for Automating Think???

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Automation & Control Technologies (Chapter 4) Overview of automation Elements of an automated system Control system Levels of enterprise

Later chapters will cover on the NC, industrial robotics, PLCs.

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Automation DefinedAutomation is the technology by which a process or procedure is accomplished without human assistance.

Basic elements of an automated system:1. Power - to accomplish the process and operate

the automated system.2. Program of instructions – to direct the process.3. Control system – to actuate the instructions.

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Elements of an Automated System

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Power to Accomplish the Automated Process Power for the process:

To drive the process itself To load and unload the work unit Transport between operations

Power for automation: Controller unit Power to actuate the control signals Data acquisition and information processing

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Program of InstructionsSet of commands that specify the sequence of steps in the work cycle and the details of each step

Example: CNC part program During each step, there are one or more activities

involving changes in one or more process parameters Examples:

Temperature setting of a furnace Axis position in a positioning system Motor on or off

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Control SystemTwo types of control:1. Closed-loop (feedback) control system – a system in

which the output variable is compared with an input parameter, and any difference between the two is used to drive the output into agreement with the input

2. Open-loop control system – operates without the feedback loop Simpler and less expensive Risk that the actuator will not have the intended effect

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(a) Feedback Control System and (b) Open-Loop Control System

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5 Levels of Automation & Control in Manufacturing1. Device level – actuators, sensors, and other hardware

components to form individual control loops for the next level

2. Machine level – CNC machine tools and similar production equipment, industrial robots, material handling equipment

3. Cell or system level – manufacturing cell or system4. Plant level – factory or production systems level5. Enterprise level – corporate information system

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Levels of Automation

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Types of Manufacturing Systems (Chapter 13) Components of a manufacturing system Material Handling System Computer Control System Classification scheme for manufacturing

systems

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Manufacturing System DefinedA collection of integrated equipment and human resources, whose function is to perform one or more processing and/or assembly operations on a starting raw material, part, or set of parts.

Equipment includes Production machines and tools Material handling and work positioning devices Computer systems

Human resources are required either full-time or periodically to keep the system running.

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Examples of Manufacturing Systems Single-station cells Machine clusters Manual assembly lines Automated transfer lines Automated assembly systems Machine cells (cellular manufacturing) Flexible manufacturing systems

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Components of a Manufacturing System1. Production Machines – plus tools & fixtures2. Material Handling System3. Computer system to coordinate and/or control the

preceding components4. Human workers to operate and manage the

system (direct labour, eg. Computer programmers, maintenance & repair personnel, etc.)

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(1) Production Machines In virtually all modern manufacturing systems,

most of the actual processing or assembly work is accomplished by machines or with the aid of tools.

Classification of production machines:1. Manually operated machines are controlled or

supervised by a human worker

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(1) Production Machines1. Semi-automated machines perform a portion

of the work cycle under some form of program control, and a worker tends the machine the rest of the cycle

2. Fully automated machines operate for extended periods of time with no human attention

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(2) Material Handling System In most manufacturing systems that process or assemble

discrete parts and products, the following material handling functions must be provided:1. Loading work units at each station2. Positioning work units at each station3. Unloading work units at each station4. Transporting work units between stations in multi-

station systems5. Temporary storage of work units

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Automated Handling of Materials Manual handling is very costly. Working process and environment could be

danger to human being. Automated handling can minimized the

risk of getting injured. More efficient and accurate. Reduction in cost

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Work Transport Between Stations Two general categories of work transport in multi-station

manufacturing systems:1. Fixed routing

Work units always flow through the same sequence of workstations

Most production lines exemplify this category2. Variable routing

Work units are moved through a variety of different station sequences

Most job shops exemplify this category

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(a) Fixed Routing and (b) Variable Routing

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(3) Computer Control System Typical computer functions in a manufacturing system:

Communicate instructions to workers for specific work. Download part programs to computer-controlled machines. Control material handling system to coordinate activities with

those of the workstations. Schedule production. Failure diagnosis when malfunctions occur. Safety monitoring. Quality control. To detect and reject defective work units. Operations management. Overall operations of the

manufacturing system.

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Classification of Manufacturing Systems Factors that define and distinguish

manufacturing systems:1. Types of operations2. Number of workstations3. System layout4. Automation and manning level 5. Part or product variety

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Types of Operations Performed Processing operations on individual work or assembly operations to

combine parts. Type(s) of materials processed. This affect the type of equipment &

handling method. Size and weight of work units. Bigger parts require bigger equipment

& higher safety required. Part or product complexity

For assembled products, number of components per product. For individual parts, number of distinct operations to complete

processing. Part geometry

Machined parts, can be rotational or non-rotational

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Three Cases of Product Variety in Manufacturing Systems

(a) Single-model case, (b) batch model case, and (c) mixed-model case

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Controllers in Manufacturing NC and industrial robotics are primarily concerned with

motion control. (NC, CNC, DNC & ROBOTICS) Discrete control uses two principal industrial controllers –

programmable logic controllers (PLCs) and personal computers (PCs).

PLCs applications are used in both process industries (food production, chemical processing) and discrete manufacturing (controlling of machines, automatic storage system, etc).

Function of PLCs: logic control, sequencing, analog control, arithmetic functions, etc.

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Numerical Control (Chapter 7) A form of programmable automation of a machine tool

(eg. drilling, milling, etc.) other equipment (non-machine such as assembly, inspection).

Generate a punched paper tape directly or to program in a computer-typed language (Automatically Programmed Tool) and process this source program off-line on a computer, which translate it into a machine readable block format program on punched paper tape. The NC machine will read the tape and repeatedly use for every part produced.

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Computer Numerical Control Each NC machine comes with a computer (MCU). Features: storage of more than one part program, program

editing at the machine tool, communications interface, etc.

CNC MCU: central processing unit, memory, I/O interface, controls for machine tool axes and spindle speed, sequence controls for other machine tool functions.

CNC Software: operating system, machine interface & application.

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DNC Direct numerical control (DNC) – control of multiple machine tools by a

single (mainframe) computer through direct connection and in real time 1960s technology Two way communication

Distributed numerical control (DNC) – network consisting of central computer connected to machine tool MCUs, which are computers (CNC) Present technology Two way communication

General Configuration of a Direct Numerical Control System

Connection to MCU is behind the tape reader (BTR). In distributed NC, entire programs are downloaded to each MCU, which is CNC rather than conventional NC.

Distributed Numerical Control Configurations

Switching network

Distributed Numerical Control Configurations

Local area network (LAN)

Computer-Aided Design (CAD) One of the fundamental building blocks of

a CIM system. It is an important technology for an integrated product development/design process.

Define: application of computers and graphics software to aid or enhance the product design from conceptualization to documentation.

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Computer-Aided Design (CAD) Application of CAD to manufacturing systems:

Used for design function. Eg. Design of product, fixtures for machining, gauges, material handling pallets, etc.

Drafting: creation of working drawings 2 components:

Hardware platform. Started with mainframe system to single user workstation

CAD software: stated with 2D, 3D capability to solid modelling.

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Production Data Management

Aka Product Lifecycle Management (PLM) / Product Development Management (PDM)

Store and organize CAD data. Control the master BOM (parts list) of product,

sub-assembly (product structure). Technique used is relational database where part

data are linked to numerous files related to part, assembly & product.

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Data Interfaces Process:

(1) creating product with CAD (2) converting CAD part geometry &

attributes to format required by others (3) saving all the different format / file

versions in the PDM’s relational database

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Computer Aided Engineering (CAE) Define: The analysis & evaluation of the engineering

design by using computer-based techniques to calculate product operational, functional and manufacturing parameters too complex for classic manual methods.

Is in the design process (from synthesis to evaluation). The output is used to determine the quality of the product design. Eg. Analysis – FEA (motion, temp, static, dynamic) & mass properties (centroid, moment of inertia, volume), evaluation (produce prototype model)

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Computer Aided Manufacturing (CAM) Define: Effective use of computer. technology in the

planning, management & control of production for the enterprise.

One major application is to extract information directly from design-drawing data. The part geometry created with CAD in the design engineering area is used with CAM software to create machine code capable to machine the part on a CNC machine - CAD/CAM).

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CAD/CAM Use CAD/CAM software to test the program in a

simulated machining process. Will construct a drawing of the “machined” part on the display screen. Upon satisfaction of the program, the computer can issue the program on a CNC machining station for execution and store the program on disk for future production runs. It can also generates three view drawings, dimension data, & programming for industrial robots to handle the product from machine to machine during production.

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Drawing Interchange File Format Autocad - .dxf, CATIA - .IGES, send to

CAM software (MasterCAM) to prepare NC/CNC programs to cut the part. Change the .dxf to its own CAM file format (APT).

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Questions Differences between NC, CNC & DNC. Benefits of CNC. Define CAD. How does CAD interface with PDM? Describe the function of PDM systems. Define CAD/CAM.

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