December 28, 2009 by
Filed under mobile nuclear medicine
INDUSTRIAL AUTOMATION
By S.Venkatesan, M.E., M.I.S.T.E., Research Scholar/CSE, Anna University, Coimbatore.
and
Dr.M.Karnan, M.E., Ph.D., Professor and head, Tamil Nadu College of Engineering, Coimbatore.
ABSTRACT: Increased automation is a key for desired increased production. In the scope of industrialization, automation is a step beyond mechanization. Whereas mechanization provided human operators with machinery to assist them with the muscular requirements of work, automation greatly reduces the need for human sensory and mental requirements as well. Processes and systems can also be automated. Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organizational tools to create complex systems for a rapidly expanding range of applications and human activities. Many roles for humans in industrial processes presently lie beyond the scope of automation. Human-level pattern recognition, language recognition, and language production ability are well beyond the capabilities of modern mechanical and computer systems. In this presentation we are about to have an overview of industrial automation concepts like computer integrated manufacturing, flexible manufacturing systems, industrial robots, artificial intelligence, advanced automatic material handling systems etc…
INTRODUCTION: AUTOMATION It is the process of following sequence of operations with little or no human labour, using specialized equipment and devices that perform and control manufacturing processes. (OR) Automation is the use of control systems (such as numerical control, programmable logic control, and other industrial control systems), in concert with other applications of information technology (such as computer-aided technologies [CAD, CAM), to control industrial machinery and processes, reducing the need for human intervention. TYPES: Partial automation Full automation MECHANISATION: The mechanization can be defined in its simplest sense as the transfer of skills and manual activities to machine operations.
AIMS OF AUTOMATION: TO IMPROVE PRODUCT QUALITY TO REDUCE LABOUR COST TO IMPROVE WORK SAFETY TO REDUCE MANUFACTURING LEAD TIME TO AVOID THE HIGH COST OF NOT AUTOMATING Advantages:
The main advantage of automation is: Replacing human operators in tedious tasks. Replacing humans in tasks that should be done in dangerous environments (i.e. fire, space, volcanoes, nuclear facilities, under the water, etc) Making tasks 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 make things too fast or too slow. Economy improvement. Sometimes and some kinds of automation implies improves in economy of enterprises, society or most of humankind. For example, when an enterprise that has invested in automation technology recovers its investment; when a state or country increases its income due to automation like Germany or Japan in the 20th Century or when the humankind can use the internet which in turn use satellites and other automated engines. Disadvantages The main disadvantages of automation are:
Technology limits. Current technology is unable to automate all the desired tasks. Unpredictable development costs. The research and development cost of automating a process is difficult to predict accurately beforehand. Since this cost can have a large impact on profitability, it’s possible to finish automating a process only to discover that there’s no economic advantage in doing so. Initial costs are relatively high. The automation of a new product required a huge initial investment in comparison with the unit cost of the product, although the cost of automation is spread in many product batches. The automation of a plant required a great initial investment too, although this cost is spread in the products to be produced. Automation tools Different types of automation tools exist: ANN – Artificial neural network DCS – Distributed Control System HMI – Human Machine Interface SCADA – Supervisory Control and Data Acquisition PAC – Programmable Automation Controller Instrumentation Motion control Robotics P PLC – Programmable Logic Controller PLC: A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes,s such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory.
A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. SCADA stands for supervisory control and data acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process. The process can be industrial, infrastructure or facility-based as described as Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes. Infrastructure processes may be public or private, and include water treatment and 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 public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption.
Computer Integrated Manufacturing Computer-Integrated Manufacturing (CIM) in engineering is a method of manufacturing in which the entire production process is controlled by computer. The traditionaly separated process methods are joined through a computer by CIM. This integration allows the processes to exchange 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 manufacturing processes. Typically CIM relies on closed-loop control processes, based on real-time input from sensors. It is also known as flexible design and manufacturing. Overview The term “Computer Integrated Manufacturing” is both a method of manufacturing and the name of a computer-automated system in which individual engineering, production, marketing, and support functions of a manufacturing enterprise are organized. In a CIM system functional areas such as design, analysis, planning, purchasing, cost accounting, inventory control, and distribution are linked through the computer with factory floor functions such as materials handling and management, providing direct control and monitoring of all process operations. As method of manufacturing, three components distinguish CIM from other manufacturing Methodologies: Means for data storage, retrieval, manipulation and presentation; Mechanisms for sensing state and modifying processes; Algorithms for uniting the data processing component with the sensor/modification component. CIM is an example of the implementation of Information and Communication Technology (ICT) in manufacturing.
CIM implies that there are at least two computers exchanging information, e.g. the controller of a arm robot and a microcontroller of a CNC machine. Some factors involved when considering a CIM implementation are the production volume, the experience of the company or personnel to make the integration, the level of the integration into the product itself and the integration of the production processes. CIM is most useful where a high level of ICT is used in the company or facility, such as CAD/CAM systems, the availability of process planning and its data. Although none of what this says is correct. History: The idea of “Digital Manufacturing” was prominent the 1980s, when Computer Integrated Manufacturing was developed and promoted by machine tool manufacturers and the Computer and Automated Systems Association and Society of Manufacturing Engineers (CASA/SME). “CIM is the integration of total manufacturing enterprise by using integrated systems and data communication coupled with new managerial philosophies that improve organizational and personnel efficiency.” ERHUM Computer Integrated manufacturing topics – Key Challenges There are three major challenges to development 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 communications protocols. In the case of AGVs, even differing lengths of time for charging the batteries may cause problems.
Data integrity: The higher the degree of automation, the more critical is the integrity of the data used to control the machines. While the CIM system saves on labor of operating the machines, it requires extra human labor in ensuring that there are proper safeguards for the data signals that are used to control the machines. Process control: Computers may be used to assist the human operators of the manufacturing facility, but there must always be a competent engineer on hand to handle circumstances which could not be foreseen by the designers of the control software. Subsystems in Computer Integrated Manufacturing A Computer Integrated Manufacturing system is not the same as a “lights out” factory, which would run completely independent of human intervention, although it is a big step in that direction. Part of the system involves flexible manufacturing, where the factory can be quickly modified to produce different products, or where the volume of products can be changed quickly 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 Aided Engineering) CAM (Computer Aided Manufacturing) CAPP (Computer Aided Process Planning) CAQ (Computer-aided quality assurance) PPC (Production planning and control) ERP (Enterprise resource planning) A business system integrated by a common database. Devices and equipment required: CNC, Computer numerical control machine tools DNC, Direct numerical control machine tools PLC’s, Programmable logic controllers Robotics Computers Software Controllers Networks Interfacing Monitoring equipment Technologies: FMS, (Flexible manufacturing system) ASRS, automated storage and retrieval systems AGV, automated guided vehicles Robotics Automated conveyance systems An industrial robot is officially defined by ISO as an automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes. The field of robotics may be more practically defined as the study, design and use of robot systems for manufacturing (a top-level definition relying on the prior definition of robot). Typical applications of robots include welding, painting, assembly, pick and place, packaging and palletizing, product inspection, and testing, all accomplished with high endurance, speed, and precision.
A flexible manufacturing system (FMS) is a manufacturing system in which there is some amount of flexibility that allows the system to react in the case of changes, whether predicted or unpredicted. This flexibility is generally considered to fall into two categories, which both contain numerous subcategories. The first category, machine flexibility, covers the system’s ability to be changed to produce new product types, and ability to change the order of operations executed on a part. The second category is called routing flexibility, which consists of the ability to use multiple machines to perform the same operation on a part, as well as the system’s ability to absorb large-scale changes, such as in volume, capacity, or capability. Most FMS systems comprise of three main systems. The work machines which are often automated CNC machines are connected by a material handling system to optimize parts flow and the central control computer which controls material movements and machine flow. The main advantages of an FMS are its high flexibility in managing manufacturing resources like time and effort in order to manufacture a new product. The best application of an FMS is found in the production of small sets of products like those from a mass production.
A flexible manufacturing system combines the benefits of highly automated and controlled systems – Accuracy – Mass production with the benefits of versatile, adjustable Systems – Flexibility – Uniqueness of product A comprehensive description of a Flexible Manufacturing System follows here: The Manufacturing Cell A flexible manufacturing cell (FMC) consists of two or more CNC machines, a cell computer and a robot. The cell computer (typically a programmable logic controller) is interfaced with the microprocessors of the robot and the CNCs. The Cell Controller The functions of the cell controller include work load balancing, part scheduling, and material flow control. The supervision and coordination among the various operations in a manufacturing cell is also performed by the cell computer. The software includes features permitting the handling of machine breakdown, tool breakage and other special situations. The Cell Robot In many applications, the cell robot also performs tool changing and housekeeping functions such as chip removal, staging of tools in the tool changer, and inspection of tools for breakage or expressive wear. When necessary, the robot can also initiate emergency procedures such as system shut-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 where materials are automatically handled and machine loaded. The flexible manufacturing system is principally used in mid-volume (200 to 30,000 parts per year) mid-variety (5 to 155 part types) production. Flexible Manufacturing System Components-Two or more computer-managed numerical work stations that perform a series of operations; An integrated material transport system and a computer that controls the flow of materials, tools, and information (e.g. machining data and machine malfunctions) throughout the system; Auxiliary work stations for loading and unloading, cleaning, inspection, etc. Flexible Manufacturing System Goals Reduction in manufacturing cost by lowering direct labor cost and minimizing scrap, re-work, and material wastage. Less skilled labor required. Reduction in work-in-process inventory by eliminating the need for batch processing Reductions in production lead time permitting manufacturers to respond more quickly to the variability of market demand Better process control resulting in consistent quality.
Different FMSs levels are: Flexible Manufacturing Module (FMM). Example: a NC machine, a pallet changer and a part buffer; Flexible Manufacturing (Assembly) Cell (F (M/A) C). Example: Four FMMs and an AGV (automated guided vehicle); Flexible Manufacturing Group (FMG). Example : Two FMCs, a FMM and two AGVs which will transport parts from a Part Loading area, through machines, to a Part Unloading Area; Flexible Production Systems (FPS). Example: A FMG and a FAC, two AGVs, an Automated Tool Storage, and an Automated Part/assembly Storage; Flexible Manufacturing Line (FML). Example: multiple stations in a line layout and AGVs. Advantages and disadvantages of FMSs implementation Advantages Faster, lower- cost changes from one part to another which will improve capital utilization Lower direct labor cost, due to the reduction in number of workers Reduced inventory, due to the planning and programming precision Consistent and better quality, due to the automated control Lower cost/unit of output, due to the greater productivity using the same number of workers Savings from the indirect labor, from reduced errors, rework, repairs and rejects Disadvantages Limited ability to adapt to changes in product or product mix (ex. machines are of limited capacity and the tooling necessary for products, even of the same family, is not always feasible in a given FMS) Substantial pre-planning activity Expensive, costing millions of dollars Technological problems of exact component positioning and precise timing necessary to process a component Sophisticated manufacturing systems FMSs complexity and cost are reasons for their slow acceptance by industry.
In most of the cases FMCs are favored. An automated guided vehicle or automatic guided vehicle (AGV) is a mobile robot that follows markers or wires in the floor, or uses vision or lasers. They are most often used in industrial applications to move materials around a manufacturing facility or a warehouse. Application of the automatic guided vehicle has broadened during the late 20th century and they are no longer restricted to industrial environments. Automated guided vehicles (AGVs) increase efficiency and reduce costs by helping to automate a manufacturing facility or warehouse. AGVs can carry loads or tow objects behind them in trailers to which they can autonomously attach. The trailers can be used to move raw materials or finished product. The AGV can also store objects on a bed. The objects can be placed on a set of motorized rollers (conveyor) and then pushed off by reversing them. Some AGVs use fork lifts 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 also done. Common AGV Applications Automated Guided Vehicles can be used in a wide variety of applications to transport many different types of material including pallets, rolls, racks, carts, and containers. AGVs excel in applications with the following characteristics: Repetitive movement of materials over a distance Regular delivery of stable loads Medium throughput/volume When on-time delivery is critical and late deliveries are causing inefficiency Operations with at least two shifts Processes where tracking material is important Artificial intelligence (AI) is the intelligence of machines and the branch of computer science 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 takes actions which maximize its chances of success. John McCarthy, who coined the term in 1956, defines it as “the science and engineering of making intelligent machines.” The field was founded on the claim that a central property of humans, intelligence—the sapience of Homo sapiens—can be so precisely described that it can be simulated by a machine. This raises philosophical issues about the nature of the mind and limits of scientific hubris, issues which have been addressed by myth, fiction and philosophy since antiquity. Artificial intelligence has been the subject of optimism, but has also suffered setbacks and, today, has become an essential part of the technology industry, providing the heavy lifting for many of the most difficult problems in computer science. AI research is highly technical and specialized, deeply divided into subfields that often fail to communicate with each other. Subfields have grown up around particular institutions, the work of individual researchers, the solution of specific problems, longstanding differences of opinion about how AI should be done and the application of widely differing tools. The central problems of AI include 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. Obotic Automation: Material Handling Processes Material handling is the broadest category of applications that involves moving, selecting or packing products. Material handling robots are used to move, feed or disengage parts or tools to or from a location, or to transfer parts from one machine to another. Material Handling Processes Pick and Place Dispensing Palletizing Packaging Part Transfer Machine Loading Assembly Material Removal Order Picking A variation of a material handling robot is used to build and unload units on a pallet. Manufacturing companies throughout the world are implementing material handling robots because of they are faster, more accurate and efficient.
They offer unmatched quality and Repeatability. Palletizing and Material Handling: 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 Milacron Robot being used to palletize advertising inserts for a newspaper. Many companies in the United States and Canada have been forced to close in such areas as die casting and injection molding because they could not compete with foreign firms. The introduction of robotics into this process has allowed the same companies to remain viable. In semiconductor industry’s IC chip manufacturing facilities; various processes take place within a clean room. This requires that personnel as well as robots not introduce dirt, dust, or oil into the area. Since robots do not breath, sneeze, or have dandruff, they are especially suited to the clean room environment demanded by the semiconductor industry. At first glance, automation might appear to devalue labor through its replacement with less-expensive machines; however, the overall effect of this on the workforce as a whole remains unclear.
Conclusion
Today automation of the workforce is quite advanced, and continues to advance increasingly more rapidly throughout the world and is encroaching on ever more skilled jobs, yet during the same period the general well-being and quality of life of most people in the world (where political factors have not muddied the picture) have improved dramatically. Currently, for manufacturing companies, the purpose of automation has shifted from increasing productivity and reducing costs, to broader issues, such as increasing quality and flexibility in the manufacturing process. The old focus on using automation simply to increase productivity and reduce costs was seen to be short-sighted, because it is also necessary to provide a skilled workforce who can make repairs and manage the machinery. Moreover, the initial costs of automation were high and often could not be recovered by the time entirely new manufacturing processes replaced the old. (Japan’s “robot junkyards” were once world famous in the manufacturing industry.) Automation is now often applied primarily to increase quality in the manufacturing process, where automation can increase quality substantially.
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