Page 292 - Sensors and Control Systems in Manufacturing

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Cha p te r
F i v e

5.4.2.2 Material Handling
Material handling is the means of loading, unloading, and transport-
ing workpieces among different machines and departments. It is
accomplished in several ways:
• Transfer lines consist of fixed automation machinery such as
conveyer belts. Their advantages are high speed and low cost.
Their major disadvantage is their lack of flexibility. Dedicated
transfer lines can handle only a limited number of parts and
cannot be easily changed once in place, thus defeating the
goals of an FMS.
• Robots provide another alternative for moving workpieces.
Generally, robots can be made very flexible because of their
programmability, but they are limited to their region of
access.
• Automated guided vehicles can move workpieces a great dis-
tance, but they lack the speed found in both robot and trans-
fer lines. Yet because of their ability to be programmed to dif-
ferent routes, they are more flexible than transfer lines.

5.4.2.3 Automated Storage and Retrieval Systems
By means of AGVs, raw materials can be taken from the loading dock
and placed in a designated place in inventory. Using an AS/RS,
inventory can be tracked throughout the manufacturing process and
optimized for strategically locating items in storage. Because the pro-
cess is computerized, data on what exactly is in inventory assist plan-
ners in determining order and production schedules.
Inventories consist of raw materials, work in process, and fin-
ished goods. Inventories should be controlled by keeping track of
inventory locations and amounts. An AS/RS can accomplish this
task.
5.4.2.4 Computer-Aided Engineering/Design/Manufacturing
(CAE/CAD/CAM)
Computer-aided design helps the engineer in many ways during the
design stage. Simply drawing the part on a computer increases the
productivity of designers, but CAD is more than just automated
drafting. It can facilitate group technology and the construction of a
bill of materials (BOM) file.
Computer-aided engineering consists of the many computerized
facets of engineering that go into a particular product. When a part
has been designed, the CAE subgroup is responsible for generating
the NC code that can be used by the NC machines on the floor.
By using GT, similar parts can be classified by similar attributes
and placed in part families. By grouping parts this way, much redun-
dancy in design and manufacturing is eliminated.