chapter 1 - introduction to automation (edited)

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DDE 3443 INDUSTRIAL AUTOMATION CHAPTER 1 INTRODUCTION TO AUTOMATION

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INTRODUCTION Production system: manufacturing support systems and facilities.

Mfg Support System

Facilities (Factory Equipments)

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INTRODUCTION cont. Mfg. Support System - procedures used to manage prod. and to solve logistics & technical prob. Facilities - the equipments in factory and the way the equipment is organized. It includes machines, tooling, material handling equipment, inspection equipment, comp. & plant layout.

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Production Facilities A manufacturing company attempts to organize its facilities in the most efficient way to serve the particular mission of the plant Certain types of plants are recognized as the most appropriate way to organize for a given type of manufacturing The most appropriate type depends on: Types of products made Production quantity Product variety

Production QuantityNumber of units of a given part or product produced annually by the plant Three quantity ranges:1. Low production 1 to 100 units 2. Medium production 100 to 10,000 units 3. High production 10,000 to millions of units

Product VarietyRefers to the number of different product or part designs or types produced in the plant Inverse relationship between production quantity and product variety in factory operations

Product variety is more complicated than a number Hard product variety products differ greatly Few common components in an assembly

Soft product variety small differences between products Many common components in an assembly

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Product Variety vs. Production Quantity

2008 Pearson Education, Inc., Upper Saddle River,

Low Production QuantityJob shop makes low quantities of specialized and customized products Also includes production of components for these products Products are typically complex (e.g., specialized machinery, prototypes, space capsules) Equipment is general purpose Plant layouts: Fixed position Process layout

Fixed-Position Layout

2008 Pearson Education, Inc., Upper Saddle River,

Process Layout

2008 Pearson Education, Inc., Upper Saddle River,

Medium Production Quantities1. Batch production A batch of a given product is produced, and then the facility is changed over to produce another product Changeover takes time setup time Typical layout process layout Hard product variety

2008 Pearson Education, Inc., Upper Saddle River,

2. Cellular manufacturing A mixture of products is made without significant changeover time between products Typical layout cellular layout Soft product variety

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Cellular Layout

High Production1. Quantity production Equipment is dedicated to the manufacture of one product Standard machines tooled for high production (e.g., stamping presses, molding machines) Typical layout process layout

2008 Pearson Education, Inc., Upper Saddle River,

2. Flow line production Multiple workstations arranged in sequence Product requires multiple processing or assembly steps Product layout is most common

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Product Layout

INTRODUCTION cont. Industrial Automation: The technology by which a process or procedure is accomplished without human assistance. A technique that can be used to reduce costs and/or to improve quality. Can increase manufacturing speed, while reducing cost.

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INTRODUCTIONcont. Can lead to products having consistent quality, perhaps even consistently good quality It is implemented using a program of instructions combined with a control system that executes the instructions.

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INTRODUCTIONcont. To automate a process, power is required, both to drive the process itself and to operate the program and control system. Automated processes can be controlled by human operators, by computers, or by a combination of the two.

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Definition 1 Automation is a technique that can be used to reduce costs and/or to improve quality. Automation can increase manufacturing speed, while reducing cost. Automation can lead to products having consistent quality, perhaps even consistently good quality. Definition 2

Automation is a technology concerned with application of mechanical, electronic and computer-based system to operate and control system. This technology includes;23

Automatic assembly machines Automation machine tools to process parts Industrial robots Automatic materials handling and storage system Automatic inspection system and quality control Feedback control and computer process control Computer system for planning, data collection and decision making to support manufacturing activities24

INTRODUCTIONcont. If a human operator is available to monitor and control a manufacturing process, open loop control may be acceptable. If a manufacturing process is automated, then it requires closed loop control, also known as feedback control. example of open loop control and closed loop control.

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Example of open loop control system

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Example of closed loop control

Temperature instruction27

Example of closed loop control

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Arguments in favor of Automation

Automation is the key to shorter work week working hours per week reduces and , allowing more leisure hours and a higher quality of life. Automation brings safer working conditions for workers. Automated production results in lower prices and better products

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Arguments against Automation It result in the subjugation of human being by a machine reduces the need for skilled labor There will be reduction in the labor force resulting un employment. Automation will reduce purchasing powermarkets will become saturated with products that people cannot afford to purchase.

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SOME CONSIDERATIONS What automation and control technology is available? Are employees ready and willing to use new technology? What technology should be used? Should the current mfg process be improve before automation? Should the product be improved before spending millions of ringgit acquiring equips.31

MANUAL LABOR IN PRODUCTION SYSTEMS Task is too technologically difficult to automate. Short product life cycle. Customized product. To cope with ups and downs in demand. To reduce risk of product failure.

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BASIC ELEMENT OF AN AUTOMATED SYSTEM Consists of 3 basic elements: 1) The actuator (which does the work) Controlled by the controller. The actuator in a automated process may in fact be several actuators, each of which provides an output that drives another in the series of actuator.

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BASIC ELEMENT OF AN AUTOMATED SYSTEMcont. Some actuators can only be on and off. Other actuators respond proportionally with the signal they receive from a controller Actuators can be selected for the types of inputs they require, either DC or AC.

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BASIC ELEMENT OF AN AUTOMATED SYSTEMcont. 2)The controller (which tells the actuator to do work) A controlled system either may be a simple digital system or an analog system. Digital and analog controllers are available off the shelf so that systems can be constructed inexpensive and with little specialized knowledge required.35

BASIC ELEMENT OF AN AUTOMATED SYSTEMcont. 3) The sensor (which provides feedback to the controller so that it knows the actuator is doing work) Obviously, controlled automation requires devices to sense system output. Sensors also can be used so that a controller can detect and respond to changing conditions in its working environment.

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BASIC ELEMENT OF AN AUTOMATED SYSTEMcont. Switches and transducers are another name for sensors. Switches can detect when a measured condition exceeds a preset level. Examples, closes when a work-piece is close enough to work on. Transducers can describe a measured condition. Examples, output increased voltage as a workpiece approaches the working zone.37

TYPE OF AUTOMATION Hard Automation Controllers were built for specific purposes and could not be altered easily. Early analog process controllers had to be rewired to be reprogrammed.

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TYPE OF AUTOMATIONcont. This controllers do what they are designed and built to do, quickly and precisely perhaps, but with little adaptability for change (beyond minor adjustments). Modification of hard automation is time-consuming and expensive, since modifications can only be performed while the equipment sits idle.39

TYPE OF AUTOMATIONcont. Soft Automation Modern digital computers are reprogrammable. It is even possible to reprogram them and test the changes while they work. Even if hardware changes are required to a soft automation system, the lost time during changeover is less than for hard automation40

AUTOMATED MFG. SYSTEM Automated Mfg. System can be classified into three basic types: Fixed Automation A system which the sequence of processing (or assembly) operations is fixed by the equipment configurations. Each operations in the sequence is usually simple.41

AUTOMATED MFG. SYSTEM cont. The features of fixed automation; High initial investment for customengineered equipment High production rates Relatively inflexible in accommodating product variety. Examples, machining transfer lines and automated assembly machines.

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AUTOMATED MFG. SYSTEM cont. Programmable Automation The production equipment is designed with the capability to change the sequence of operations to accommodate different product configurations. The operation sequence is controlled by a program, which is a set of instruction coded so that they can be read and interpreted by the system.43

AUTOMATED MFG. SYSTEM cont. New pr