INDUSTRIAL AUTOMATION
By S.Venkatesan, M.E., M.I.S.T.E., Research Scholar/CSE, Anna University,Coimbatore.
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Dr.M.Karnan, M.E., Ph.D., Professor and head, Tamil Nadu College ofEngineering, Coimbatore.
ABSTRACT: Increased automation is a key for desired increasedproduction. In the scope of industrialization, automation is a step beyondmechanization. Whereas mechanization provided human operators with machinery toassist them with the muscular requirements of work, automation greatly reducesthe need for human sensory and mental requirements as well. Processes andsystems can also be automated. Automation plays an increasingly important rolein the global economy and in daily experience. Engineers strive to combineautomated devices with mathematical and organizational tools to create complexsystems for a rapidly expanding range of applications and human activities.Many roles for humans in industrial processes presently lie beyond the scope ofautomation. Human-level pattern recognition, language recognition, and languageproduction ability are well beyond the capabilities of modern mechanical andcomputer systems. In this presentation we are about to have an overview ofindustrial automation concepts like computer integrated manufacturing, flexiblemanufacturing systems, industrial robots, artificial intelligence, advancedautomatic material handling systems etc…
INTRODUCTION: AUTOMATION It is the process of following sequence ofoperations with little or no human labour, using specialized equipment anddevices that perform and control manufacturing processes. (OR) Automation isthe use of control systems (such as numerical control, programmable logiccontrol, and other industrial control systems), in concert with otherapplications of information technology (such as computer-aided technologies[CAD, CAM), to control industrial machinery and processes, reducing the needfor human intervention. TYPES: Partial automation Full automationMECHANISATION: The mechanization can be defined in its simplest sense as thetransfer of skills and manual activities to machine operations.
AIMS OF AUTOMATION: TO IMPROVE PRODUCT QUALITY TO REDUCE LABOUR COSTTO IMPROVE WORK SAFETY TO REDUCE MANUFACTURING LEAD TIME TO AVOID THE HIGH COSTOF NOT AUTOMATING Advantages:
The main advantage of automation is: Replacing human operators in tedioustasks. Replacing humans in tasks that should be done in dangerous environments(i.e. fire, space, volcanoes, nuclear facilities, under the water, etc) Makingtasks that are beyond the human capabilities such as handling too heavy loads,too large objects, too hot or too cold substances or the requirement to makethings too fast or too slow. Economy improvement. Sometimes and some kinds ofautomation implies improves in economy of enterprises, society or most ofhumankind. For example, when an enterprise that has invested in automationtechnology recovers its investment; when a state or country increases itsincome due to automation like Germany or Japan in the 20th Century or when thehumankind can use the internet which in turn use satellites and other automatedengines. Disadvantages The main disadvantages of automation are:
Technology limits. Current technology is unable to automate all the desiredtasks. Unpredictable development costs. The research and development cost ofautomating a process is difficult to predict accurately beforehand. Since thiscost can have a large impact on profitability, it's possible to finishautomating a process only to discover that there's no economic advantage indoing so. Initial costs are relatively high. The automation of a new productrequired a huge initial investment in comparison with the unit cost of theproduct, although the cost of automation is spread in many product batches. Theautomation of a plant required a great initial investment too, although thiscost is spread in the products to be produced. Automation tools Different typesof automation tools exist: ANN - Artificial neural network DCS - DistributedControl System HMI - Human Machine Interface SCADA - Supervisory Control andData Acquisition PAC - Programmable Automation Controller InstrumentationMotion control Robotics P PLC - Programmable Logic Controller PLC: Aprogrammable logic controller (PLC) or programmable controller is a digitalcomputer used for automation of electromechanical processes,s such as controlof machinery on factory assembly lines, amusement rides, or lighting fixtures.PLCs are used in many industries and machines. Unlike general-purposecomputers, the PLC is designed for multiple inputs and output arrangements,extended temperature ranges, immunity to electrical noise, and resistance tovibration and impact. Programs to control machine operation are typicallystored in battery-backed or non-volatile memory.
A PLC is an example of a real time system since output results must beproduced in response to input conditions within a bounded time, otherwiseunintended operation will result. SCADA stands for supervisory control and dataacquisition. It generally refers to an industrial control system: a computersystem monitoring and controlling a process. The process can be industrial,infrastructure or facility-based as described as Industrial processes includethose of manufacturing, production, power generation, fabrication, andrefining, and may run in continuous, batch, repetitive, or discrete modes.Infrastructure processes may be public or private, and include water treatmentand distribution, wastewater collection and treatment, oil and gas pipelines,electrical power transmission and distribution, civil defense siren systems,and large communication systems. Facility processes occur both in publicfacilities and private ones, including buildings, airports, ships, and spacestations. They monitor and control HVAC, access, and energy consumption.
Computer Integrated Manufacturing Computer-Integrated Manufacturing (CIM) inengineering is a method of manufacturing in which the entire production processis controlled by computer. The traditionaly separated process methods arejoined through a computer by CIM. This integration allows the processes toexchange information with each other and enable them to initiate actions.Through this integration, manufacturing can be faster and with fewer errors.Yet, the main advantage is the ability to create automated manufacturingprocesses. Typically CIM relies on closed-loop control processes, based onreal-time input from sensors. It is also known as flexible design andmanufacturing. Overview The term "Computer Integrated Manufacturing" is both amethod of manufacturing and the name of a computer-automated system in whichindividual engineering, production, marketing, and support functions of amanufacturing enterprise are organized. In a CIM system functional areas suchas design, analysis, planning, purchasing, cost accounting, inventory control,and distribution are linked through the computer with factory floor functionssuch as materials handling and management, providing direct control andmonitoring of all process operations. As method of manufacturing, threecomponents distinguish CIM from other manufacturing Methodologies: Means fordata storage, retrieval, manipulation and presentation; Mechanisms for sensingstate and modifying processes; Algorithms for uniting the data processingcomponent with the sensor/modification component. CIM is an example of theimplementation of Information and Communication Technology (ICT) inmanufacturing.
CIM implies that there are at least two computers exchanginginformation, e.g. the controller of a arm robot and a microcontroller of a CNCmachine. Some factors involved when considering a CIM implementation are theproduction volume, the experience of the company or personnel to make theintegration, the level of the integration into the product itself and theintegration of the production processes. CIM is most useful where a high levelof ICT is used in the company or facility, such as CAD/CAM systems, theavailability of process planning and its data. Although none of what this saysis correct. History: The idea of "Digital Manufacturing" was prominent the1980s, when Computer Integrated Manufacturing was developed and promoted bymachine tool manufacturers and the Computer and Automated Systems Associationand Society of Manufacturing Engineers (CASA/SME). "CIM is the integration oftotal manufacturing enterprise by using integrated systems and datacommunication coupled with new managerial philosophies that improveorganizational and personnel efficiency." ERHUM Computer Integratedmanufacturing topics - Key Challenges There are three major challenges todevelopment of a smoothly operating Computer Integrated Manufacturing system:Integration of components from different suppliers: When different machines,such as CNC, conveyors and robots, are using different communicationsprotocols. In the case of AGVs, even differing lengths of time for charging thebatteries may cause problems.
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Data integrity: The higher the degree of automation, the more critical isthe integrity of the data used to control the machines. While the CIM systemsaves on labor of operating the machines, it requires extra human labor inensuring that there are proper safeguards for the data signals that are used tocontrol the machines. Process control: Computers may be used to assist thehuman operators of the manufacturing facility, but there must always be acompetent engineer on hand to handle circumstances which could not be foreseenby the designers of the control software. Subsystems in Computer IntegratedManufacturing A Computer Integrated Manufacturing system is not the same as a“lights out” factory, which would run completely independent of humanintervention, although it is a big step in that direction. Part of the systeminvolves flexible manufacturing, where the factory can be quickly modified toproduce different products, or where the volume of products can be changedquickly with the aid of computers.
Some or all of the following subsystems may be found in a CIM operation:Computer-aided techniques: CAD (Computer Aided Design) CAE (Computer AidedEngineering) CAM (Computer Aided Manufacturing) CAPP (Computer Aided ProcessPlanning) CAQ (Computer-aided quality assurance) PPC (Production planning andcontrol) ERP (Enterprise resource planning) A business system integrated by acommon database. Devices and equipment required: CNC, Computer numericalcontrol machine tools DNC, Direct numerical control machine tools PLC’s,Programmable logic controllers Robotics Computers Software Controllers NetworksInterfacing Monitoring equipment Technologies: FMS, (Flexible manufacturingsystem) ASRS, automated storage and retrieval systems AGV, automated guidedvehicles Robotics Automated conveyance systems An industrial robot isofficially defined by ISO as an automatically controlled, reprogrammable,multipurpose manipulator programmable in three or more axes. The field ofrobotics may be more practically defined as the study, design and use of robotsystems for manufacturing (a top-level definition relying on the priordefinition of robot). Typical applications of robots include welding, painting,assembly, pick and place, packaging and palletizing, product inspection, andtesting, all accomplished with high endurance, speed, and precision.
A flexible manufacturing system (FMS) is a manufacturing system in whichthere is some amount of flexibility that allows the system to react in the caseof changes, whether predicted or unpredicted. This flexibility is generallyconsidered to fall into two categories, which both contain numeroussubcategories. The first category, machine flexibility, covers the system’sability to be changed to produce new product types, and ability to change theorder of operations executed on a part. The second category is called routingflexibility, which consists of the ability to use multiple machines to performthe same operation on a part, as well as the system’s ability to absorblarge-scale changes, such as in volume, capacity, or capability. Most FMSsystems comprise of three main systems. The work machines which are oftenautomated CNC machines are connected by a material handling system to optimizeparts flow and the central control computer which controls material movementsand machine flow. The main advantages of an FMS are its high flexibility inmanaging manufacturing resources like time and effort in order to manufacture anew product. The best application of an FMS is found in the production of smallsets of products like those from a mass production.
A flexible manufacturing system combines the benefits of highly automatedand controlled systems – Accuracy – Mass production with the benefits ofversatile, adjustable Systems – Flexibility – Uniqueness of product Acomprehensive description of a Flexible Manufacturing System follows here: TheManufacturing Cell A flexible manufacturing cell (FMC) consists of two or moreCNC machines, a cell computer and a robot. The cell computer (typically aprogrammable logic controller) is interfaced with the microprocessors of therobot and the CNCs. The Cell Controller The functions of the cell controllerinclude work load balancing, part scheduling, and material flow control. Thesupervision and coordination among the various operations in a manufacturingcell is also performed by the cell computer. The software includes featurespermitting the handling of machine breakdown, tool breakage and other specialsituations. The Cell Robot In many applications, the cell robot also performstool changing and housekeeping functions such as chip removal, staging of toolsin the tool changer, and inspection of tools for breakage or expressive wear.When necessary, the robot can also initiate emergency procedures such as systemshut-down. Parker-Hannifin Corporation, Forrest City, NC.
The Flexible Manufacturing System – FMS The flexible manufacturing system(FMS) is a configuration of computer-managed numerical work stations wherematerials are automatically handled and machine loaded. The flexiblemanufacturing system is principally used in mid-volume (200 to 30,000 parts peryear) mid-variety (5 to 155 part types) production. Flexible ManufacturingSystem Components-Two or more computer-managed numerical work stations thatperform a series of operations; An integrated material transport system and acomputer that controls the flow of materials, tools, and information (e.g.machining data and machine malfunctions) throughout the system; Auxiliary workstations for loading and unloading, cleaning, inspection, etc. FlexibleManufacturing System Goals Reduction in manufacturing cost by lowering directlabor cost and minimizing scrap, re-work, and material wastage. Less skilledlabor required. Reduction in work-in-process inventory by eliminating the needfor batch processing Reductions in production lead time permittingmanufacturers to respond more quickly to the variability of market demandBetter process control resulting in consistent quality.
Different FMSs levels are: Flexible Manufacturing Module (FMM). Example: aNC machine, a pallet changer and a part buffer; Flexible Manufacturing(Assembly) Cell (F (M/A) C). Example: Four FMMs and an AGV (automated guidedvehicle); Flexible Manufacturing Group (FMG). Example : Two FMCs, a FMM and twoAGVs which will transport parts from a Part Loading area, through machines, toa Part Unloading Area; Flexible Production Systems (FPS). Example: A FMG and aFAC, two AGVs, an Automated Tool Storage, and an Automated Part/assemblyStorage; Flexible Manufacturing Line (FML). Example: multiple stations in aline layout and AGVs. Advantages and disadvantages of FMSs implementationAdvantages Faster, lower- cost changes from one part to another which willimprove capital utilization Lower direct labor cost, due to the reduction innumber of workers Reduced inventory, due to the planning and programmingprecision Consistent and better quality, due to the automated control Lowercost/unit of output, due to the greater productivity using the same number ofworkers Savings from the indirect labor, from reduced errors, rework, repairsand rejects Disadvantages Limited ability to adapt to changes in product orproduct mix (ex. machines are of limited capacity and the tooling necessary forproducts, even of the same family, is not always feasible in a given FMS)Substantial pre-planning activity Expensive, costing millions of dollarsTechnological problems of exact component positioning and precise timingnecessary to process a component Sophisticated manufacturing systems FMSscomplexity and cost are reasons for their slow acceptance by industry.
In most of the cases FMCs are favored. An automated guided vehicle orautomatic guided vehicle (AGV) is a mobile robot that follows markers or wiresin the floor, or uses vision or lasers. They are most often used in industrialapplications to move materials around a manufacturing facility or a warehouse.Application of the automatic guided vehicle has broadened during the late 20thcentury and they are no longer restricted to industrial environments. Automatedguided vehicles (AGVs) increase efficiency and reduce costs by helping toautomate a manufacturing facility or warehouse. AGVs can carry loads or towobjects behind them in trailers to which they can autonomously attach. Thetrailers can be used to move raw materials or finished product. The AGV canalso store objects on a bed. The objects can be placed on a set of motorizedrollers (conveyor) and then pushed off by reversing them. Some AGVs use forklifts to lift objects for storage. AGVs are employed in nearly every industry,including, pulp, paper, metals, newspaper, and general manufacturing.Transporting materials such as food, linen or medicine in hospitals is alsodone. Common AGV Applications Automated Guided Vehicles can be used in a widevariety of applications to transport many different types of material includingpallets, rolls, racks, carts, and containers. AGVs excel in applications withthe following characteristics: Repetitive movement of materials over a distanceRegular delivery of stable loads Medium throughput/volume When on-time deliveryis critical and late deliveries are causing inefficiency Operations with atleast two shifts Processes where tracking material is important Artificialintelligence (AI) is the intelligence of machines and the branch of computerscience which aims to create it.
Textbooks define the field as “the study and design of intelligent agents,”where an intelligent agent is a system that perceives its environment and takesactions which maximize its chances of success. John McCarthy, who coined theterm in 1956, defines it as “the science and engineering of making intelligentmachines.” The field was founded on the claim that a central property ofhumans, intelligence—the sapience of Homo sapiens—can be so precisely describedthat it can be simulated by a machine. This raises philosophical issues aboutthe nature of the mind and limits of scientific hubris, issues which have beenaddressed by myth, fiction and philosophy since antiquity. Artificialintelligence has been the subject of optimism, but has also suffered setbacksand, today, has become an essential part of the technology industry, providingthe heavy lifting for many of the most difficult problems in computer science.AI research is highly technical and specialized, deeply divided into subfieldsthat often fail to communicate with each other. Subfields have grown up aroundparticular institutions, the work of individual researchers, the solution ofspecific problems, longstanding differences of opinion about how AI should bedone and the application of widely differing tools. The central problems of AIinclude such traits as reasoning, knowledge, planning, learning, communication,perception and the ability to move and manipulate objects. General intelligence(or “strong AI”) is still a long-term goal of (some) research. OboticAutomation: Material Handling Processes Material handling is the broadestcategory of applications that involves moving, selecting or packing products.Material handling robots are used to move, feed or disengage parts or tools toor from a location, or to transfer parts from one machine to another. MaterialHandling Processes Pick and Place Dispensing Palletizing Packaging PartTransfer Machine Loading Assembly Material Removal Order Picking A variation ofa material handling robot is used to build and unload units on a pallet.Manufacturing companies throughout the world are implementing material handlingrobots because of they are faster, more accurate and efficient.
They offer unmatched quality and Repeatability. Palletizing and MaterialHandling: Palletizing is the act of loading or unloading material onto pallets.The newspaper industry has been particularly hard hit by increased labor costs.Part of the solution to this problem was to use robots like Cincinnati MilacronRobot being used to palletize advertising inserts for a newspaper. Manycompanies in the United States and Canada have been forced to close in suchareas as die casting and injection molding because they could not compete withforeign firms. The introduction of robotics into this process has allowed thesame companies to remain viable. In semiconductor industry’s IC chipmanufacturing facilities; various processes take place within a clean room.This requires that personnel as well as robots not introduce dirt, dust, or oilinto the area. Since robots do not breath, sneeze, or have dandruff, they areespecially suited to the clean room environment demanded by the semiconductorindustry. At first glance, automation might appear to devalue labor through itsreplacement with less-expensive machines; however, the overall effect of thison the workforce as a whole remains unclear.
Conclusion
Today automation of the workforce is quite advanced, and continues toadvance increasingly more rapidly throughout the world and is encroaching onever more skilled jobs, yet during the same period the general well-being andquality of life of most people in the world (where political factors have notmuddied the picture) have improved dramatically. Currently, for manufacturingcompanies, the purpose of automation has shifted from increasing productivityand reducing costs, to broader issues, such as increasing quality andflexibility in the manufacturing process. The old focus on using automationsimply to increase productivity and reduce costs was seen to be short-sighted,because it is also necessary to provide a skilled workforce who can makerepairs and manage the machinery. Moreover, the initial costs of automationwere high and often could not be recovered by the time entirely newmanufacturing processes replaced the old. (Japan’s “robot junkyards” were onceworld famous in the manufacturing industry.) Automation is now often appliedprimarily to increase quality in the manufacturing process, where automationcan increase quality substantially.
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