Page 345 - Concise Encyclopedia of Robotics

VACUUM CUP GRIPPER V
A vacuum cup gripper is a specialized robotic end effector that employs
suction to lift and move objects. The device consists of the gripper mech-
anism itself, a hose, an air pump, a power supply, and a connection to the
robot controller.
In order to move an object from one location to another, the robot arm
places the cup-shaped, flexible gripper against the surface of the object,
which must be clean and nonporous so that air cannot leak around the
edges of the cup. Then the robot controller actuates the motor, creating a
partial vacuum inside the hose and cup assembly. Next, the robot arm
moves the gripper from the initial node (starting position) to the intended
goal node (final position). Then the robot controller briefly reverses the
motor, so the pressure inside the hose and cup assembly returns to normal
atmospheric pressure. Finally, the robot arm moves the gripper away
from the object.
The principal asset of the vacuum cup gripper is the fact that it does
not allow objects to slide out of position as they are moved. However, this
type of gripper operates at limited speed, and is not capable of handling
massive objects safely.
See also ROBOT GRIPPER.

VIA POINT
The term via point refers to any point through which a robot end effector
passes as a manipulator moves it from the initial node (starting position)
to the goal node (final position).
In the case of a robot arm that employs continuous-path motion, there
are theoretically an infinite number of via points. In the case of point-to-
point motion, the via points are those points at which the end effector can
be halted; this set of points is finite.
See also CONTINUOUS-PATH MOTION and POINT-TO-POINT MOTION.


Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use.