Fixed Automation:
Fixed automation is a system in which the sequence of processing (or assembly) operations is fixed by the equipment configuration. Each operation in the sequence is usually simple, involving perhaps a plain linear or rotational motion or an uncomplicated combination of the two, such as the feeding of a rotating spindle.It is the integration and coordination of many such operations into one piece of equipment that makes the system complex. Typical features of a fixed automation are 1) high initial investment for custom-engineered equipment, 2) high production rates, 3) relative inflexibility of the equipment to accomodate product varicity. The economic justification for fixed automation is found in products that are produceed in very large quantities and high production rates. The high initial cost of equipment can be spread over a very large number of units, thus making the unit cost attractive compared to alternative methods of production. Examples of fixed automation include machining transfer lines and automated assembly machines.
(M.P. Groover, Automation, production systems, and computer-integrated manufacturing, 3rd Edition, p. 10)
Programmable Automation:
In programable automation, the production equipment is designed with capability to change the sequence of operations to accomodate different product configurations. The operation sequence is controlled by a program, which is a set insturctions coded so that they can be read and interpreted by the system. New programs can be prepared and entered into the equipment to produce new products. Some of the features characterize programmable automation include, 1) high investment in general purpose equipment, 2) lower production rates than fixed automation, 3) flexibly to deal with the variations and chages in product configuration, and 4) high suitability for batch operations. Programmable automated production systems are used in low- and medium- volume production. The parts or products are typically made in batches. To produce each new batch of a different product, system must be reprogrammed with the set of machine instructions that correspond to the new product. The physical set up of the machine must also be changed: Tools must be loaded, fixtures must be attached to the machine table and the required machine settings must be entered. This changeover procedure takes time. Consequently, the typical cycle for a given product includes a period during which the setup and reprogramming takes place, followed by a period in which the parts in the batch are produced. Examples of programmable automation include numerically controlled machine tools, industrial robots, and programmable logic controllers.
(M.P. Groover, Automation, production systems, and computer-integrated manufacturing, 3rd Edition, p. 10-11)
Functional Layout:
In a functional layout, machines performing similar functions are organised in one center. For example, drilling is done in the drilling cell, face milling in the face milling cell, so on. Such a layout is adopted when different products must be produced intermittently at the same set of work stations. A functional layout is usually adopted when the volume of parts produced is too low to allow human and capital recources to be set aside exclusively for a particular set of parts. An advantage of the functional layout is that employee suopervision can be more specialized. However a functional layout tends to increase setup costs, and throughput time because of the frequent change overfro part type to the next.
(George Winston Zobrist, Chung You Ho, Progress in robotics and intelligent systems, Volume 1, p.263-264)
Laser Additive Manufacturing:
The laser additive manufacturing process (LAMP) is a large scale manufacturing capabilty developed and operated in AeroMet Corporation in Eden Prairie, MN. The LAMP process uses a laser to sinter deposited titanium powder much like the LENS and POM processes. The key difference with LAMP is the high deposition capability and large working envelope: the system deposites 10 to 12 pounds of metal per minute, at a 95% or better powder usage rate, and has an expandable working area of a minimum 4'x4'x4'. The laser system is very large, and the laser beam is actually piped in through a wall using fiber optic tubing. LAMP parts are typically built with about 0.050" tolerances, which are then final machined to meet dimensional requirements.
(Kenneth G. Cooper, Rapid Prototyping Technology: Selection and Application, p. 129)
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