Computers In Mfg

COMPUTER INTEGRA TED MANUFACTURING

LESSON 2: APPLICATIONS OF COMPUTERS IN MANUFACTURING Topics Covered Various computer applications in Manufacturing such as CNC, Adaptive control, robots, Automated Material handling

Objectives • • •

Upon completion of this Lesson, you should be able to Know the benefits of CIM· Know about outline of major computer applications in CIM

c. Industrial robots. Introduced in the early 1960s, industrial robots have been replacing humans in operations that are repetitive, boring, and dangerous, thus reducing the possibility of human error, decreasing variability in product quality, and improving productivity, Robots with sensoryperception capabilities are being developed (intelligent robots), with movements that simulate those of humans. (Fig 2.1 shows a painting robot in action).

Know about factory of the future

The major goals of automation in manufacturing facilities are to integrate various operations so as to improve productivity, to increase product quality and uniformity, to minimize cycle times, and to reduce labour costs. Beginning in the 1940s, automation has accelerated because of rapid advances in control systems for machines and in computer technology. Few developments in the history of manufacturing have had a more significant impact than computers. Computers are now used in a very broad range of applications, including control and optimisation of manufacturing processes, material handling, assembly, automated inspection and testing of products, inventory control, and numerous management activities, Beginning with computer graphics and computeraided design and manufacturing, the use of computers has been extended to computer-integrated manufacturing (CIM). Computer- integrated manufacturing is particularly effective because of its capability for making possible: i

Responsiveness to rapid changes in market demand and product modification.

ii

Better use of materials, machinery, and personnel, and reduction in inventory

iii Better control of production and management of the total manufacturing operation; and iv The manufacture of high-quality products at low cost. The following is an outline of the major applications of computers in manufacturing a. Computer numerical control (CNC). This is a method of controlling the movement of machine components by direct insertion of coded instructions in the form of numerical data. Numerical control was first implemented in the early 1950s and was a major advance in automation of machines.

Fig 2.1 A painting Robot d. Automated handling of materials. Computers have made possible highly efficient handling of materials and products in various stages of completion (work in progress) such as when being moved from storage to machines or from machine to machine and when at the points of inspection, inventory, and shipment. e. Automated and robotic assembly systems are replacing costly assembly by human operators. Products are designed or redesigned so that they can be assembled more eas-ily by machine. (Fig. 2.2 Shows robots on an assembly line)

b. Adaptive control (AC). The parameters in a manufacturing process are adjusted automatically to optimise production rate and product quality and to minimize cost. Parameters such as forces, temperatures, surface finish, and dimensions of the part are monitored constantly. If they move outside the acceptable range, the system adjusts the process variables until the parameters again fall within the acceptable range.

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f. Computer-aided process planning (CAPP): This tool is capable of improving pro-ductivity in a plant by optimising process plans, reducing planning costs, and im-proving the consistency of product quality and reliability. Functions such as the estimating of cost and the monitoring of work standards (time required to perform a certain operation) can also be incorporated into the system. g. Group technology (GT) The concept of group technology is that parts can be grouped and produced by classifying them into families, according to similarities in design and similarities in the manufacturing processes employed to produce the part. In this way, part designs and process plans can be standardized, and families of like parts can be produced efficiently and economically. h. Just-in-time production (JIT): The principal of JIT is that supplies are delivered just in time to be used, parts are produced just in time to be made into subassemblies and assemblies, and products are finished just in time to be delivered to the customer. In this way, inventory-carrying costs are low, part defects are detected right away, productivity is increased, and high-quality products are made at low cost. i. Cellular manufacturing: Cellular manufacturing involves workstations, called manufacturing cells, usually containing several machines controlled by a central robot, each machine performing a different operation on the part. j. Flexible manufacturing systems (FMS): This methodology integrates manufactur-ing cells into a large unit, all interfaced with a central computer. Flexible manufacturing systems have the highest level of efficiency, sophistication, and pro-ductivity among manufacturing systems. Although very costly, they are capable of efficiently producing parts in small runs and of changing manufacturing sequences on different parts quickly; this flexibility enables them to meet rapid changes in market demand for various types of products. k. Expert systems: These are, basically, complex computer programs. They are rapid-ly developing the capability to perform tasks and solve difficult real-life problems much as human experts would.

manufacturing facilities with state-of-the-art equipment for training for prototype development, and for small-scale production runs, and it would be avail able to help small companies develop products that compete in the global marketplace. In view of these advances and their potential, some experts have envisioned the factory of the future. Although highly controversial, and viewed as unrealistic by some, this is a system in which production will take place with little or no direct human intervention. The human role is expected to be confined to the supervision, maintenance, and upgrading of ma-chines, computers, and software. The implementation of some of the modem technologies briefly outlined above requires significant technical and economic expertise, time, and capital investment. Some of the high technology can be applied improperly, or it can be implemented on too large or am-bitious a scale, one involving major expenditures with questionable return on investment. In consequence, it is essential to perform a comprehensive assessment of the real and spe-cific needs of a company and of the market for its products, as well as of whether there is good communication among the parties involved, such as the vendors, the suppliers, the technical personnel, and the company’s management. Exercises/Points to Ponder • • •

What are various applications of Computers in Manufacturing system Find out the mechanisms for adaptive control in Manufacturing systems Try to see different models of Robots on the Internet Using Google Image search and also try to find out about their manufacture construction and working

Internet References Lectures in CIM http://www.uky.edu/~dsianita/611/class2.html Notes

l. Artificial intelligence (AI): This field involves the use of machines and computers to replace human intelligence. Computer-controlled systems are becoming capable of learning from experience and of making decisions that optimise operations and minimize costs. Artificial neural networks, which are designed to simulate the thought processes of the human brain, have the capability of modelling and simulating pro-duction facilities, monitoring and controlling manufacturing processes, diagnosing problems in machine performance, conducting financial planning, and managing a company’s manufacturing strategy. m. Shared manufacturing: Although large corporations can afford to implement modem technology and take risks, smaller companies generally have difficulty in doing so with their limited personnel, resources, and capital. More recently, the concept of shared manufacturing has been proposed. This would consist of a regional or nation-, wide network of

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COMPUTER INTEGRA TED MANUFACTURING

Fig. 2.2 Robots Working on an assembly line