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Cha p te r

FIGURE 8.5 Ei g h t
Presence or
absence of items
in an assembly.

Vision camera

X axis

Video
system

Printer
FIGURE 8.6 Object in fi eld of view.

8.5.2 Components of Robot Vision
Figure 8.7 is a schematic diagram of the main components of a robot
in a typical vision process for manufacturing. A fixed camera surveys
a small, carefully lighted area where the objects to be located or
inspected are placed. When visual information is needed (as signaled
by some external switch or sensors), a digitizer in a robot vision sys-
tem converts the camera image into a “snapshot”: a significant array
of integer brightness values (called gray levels). This array is sorted
in a large random access memory (RAM) array in the robot-vision
system called an image buffer or a frame buffer. Once sorted, the image
can be displayed on a monitor at any time. More importantly, the
image can be analyzed or manipulated by a vision computer, which
can be programmed to solve robot vision problems. The vision com-
puter is often connected to a separate general-purpose (host) computer,