Page 48 - Concise Encyclopedia of Robotics

Biped Robot
The problem of making androids can be approached from two direc-
tions. On the one hand, biological robots might be grown in laboratories
by a process of cloning. This idea is clouded by profound ethical issues.
On the other hand, engineers can try to build a mechanical robot with
the dexterity and intelligence of a human being. This notion, too, brings
up ethical questions, but to a lesser degree.
See also ANDROID, BIOCHIP, BIOLOGICAL ROBOT, BIOMECHANISM, and CYBORG.
BIPED ROBOT
A biped robot is a robot with two legs that are used for support and
propulsion. Usually, but not always, such robots have arms and a head, so
they are androids.
Physically, biped robots are unstable unless equipped with specialized
balancing systems. Humans can manage with two legs because the brain
and inner ear together constitute a feedback system that provides a good
sense of balance. The human sense of balance can be duplicated electro-
mechanically, but the designs are sophisticated and expensive.
Robots that use legs for propulsion generally have four or six legs,
because these designs offer better inherent stability than the biped scheme.
See also INSECT ROBOT, QUADRUPED ROBOT, and ROBOT LEG.
BIT-MAPPED GRAPHICS
In a robotic vision system, an image can be assembled from thousands of
tiny square elements. The smaller the elements, called pixels, the more
detail the image can show for a given image size. Images made this way
are bit-mapped graphics, also known as raster graphics.
On a computer display, the image you see is a pattern of pixels in a fine,
interwoven mesh. You can observe these pixels if you dim your monitor
so you can hardly see the image (this is important!) and then look closely
at it through a high-powered magnifying lens. A computer stores bit-
mapped graphic images as a vast array of logic highs and lows (ones and
zeros). To obtain an image from this array of bits, the computer employs
a function called a bit map.
Bit-mapped graphics always produce approximations of scenes or
objects. This is because each pixel is a square, and can take only certain
digital values. If the number of pixels in an image is extremely large, the
approximation is a good representation of reality in most instances. How-
ever, the detail obtainable with bit-mapped graphics is always limited by
the image resolution.
Bit-mapped graphics produce an artifact called jaggies or aliasing, a
peculiar “digitized” appearance in the edges of rendered objects. Vertical
and horizontal lines look all right, but curves and diagonals are roughened
with “saw teeth.”To some extent this can be reduced by means of antialiasing

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