Fixed construction automation is useful in mass production
or prefabrication of building components such as:
1. Reinforcing steel
2. Structural steel
3. Exterior building components (e.g., masonry, granite
stone, precast concrete)
Automated Rebar Prefabrication System
The automated rebar prefabrication system places reinforcing
bars for concrete slab construction. The system consists of a NEC PC98000XL
high-resolution-mode personal computer that uses AutoCAD™ DBASE III Plus™, and
BASIC™ software.
The information regarding number, spacing, grade and dimension,
and bending shapes of rebars is found from the database generated from an
AutoCAD file. This information is used by an automatic assembly system to
fabricate the rebar units.
The assembly system consists of two vehicles and a steel
rebar arrangement support base. Of the two vehicles, one moves in the
longitudinal direction and the other in the transverse direction. The
longitudinally moving vehicle carries the rebars forward until it reaches the
preset position.
Then, it moves backward and places the rebars one by one at
preset intervals on the support base. Upon completion of placement of the
rebars by the longitudinally moving vehicle, the transversely moving vehicle
places the rebars in a similar manner. The mesh unit formed by such a placement
of rebars is tied together automatically [Miyatake and Kangari, 1993].
Automated Brick Masonry
The automated brick masonry system, is designed to spread
mortar and place bricks for masonry wall construction. The system consists of:
1. Mortar-spreading module
2. Brick-laying station
The controls of the system are centered around three
personal computers responsible for:
1. Collecting and storing date in real time
2. Interfacing a stepping-motor controller and a robot
controller
3. Controlling the mortar-spreading robot
A Lord 15/50 force-torque sensor is used to determine the
placing force of each brick. The system is provided with an integrated control
structure that includes a conveyor for handling the masonry bricks [Bernold et
al., 1992].
Fully Automated Masonry Plant
The fully automated masonry plant is designed to produce
different brick types with the production capacity of 300 m2 wall elements per
shift. The system consists of several components: a master computer, a database
server, a file server, stone cutters, masonry robots, pallet rotation systems,
refinement systems, storage systems, transversal platforms, a disposition
management system, an inventory management system, and a CAD system.
Two individual brick types can be managed in parallel by
unloading the gripper and the cutter-system consisting of two stone saws. By
conveyer systems, stone units and fitting stones are transported to the masonry
robot system.
The masonry robots move two bricks at each cycle to the
growing wall after a mortar robot puts a layer of mortar on it. A pallet
rotation system carries the wall to the drying chamber. After 48 hours, the
wall is transported to destacking stations to group the wall elements of the
same order. Finally, grouped wall elements are transported to the construction
site [Hanser, 1999].
Automated Stone Cutting
The purpose of the automated stone-cutting facility is to
precut stone elements for exterior wall facings. The facility consists of the
following subsystems:
1. Raw materials storage
2. Loading
3. Primary workstation
4. Detail workstation
5. Inspection station
6. End-product inventory
A special lifting device has been provided for automated
materials handling. The boom’s rigidity enables the computation of exact
location and orientation of the hook. Designs for the pallets, the primary saw
table, the vacuum lift assembly, and the detail workstation have also been
proposed [Bernold et al., 1992].
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