manipulators. Generally, computations of one link depend
upon other links. These computations must be done
serially, thus making parallel processing difficult and
ineffective in reducing computation time. With parallel-
type configuration in the manipulators, the computation can
be performed in parallel. Therefore, the computation time
will be significantly reduced. In general, the computations
required for inverse kinematics and Jacobian matrices will
be less complicated than those of serial open-loop
manipulators, but the computations for direct kinematics are
much involved.
Based on this new possibility, we describe possible
manipulator configuration linkages with six degrees of
freedom. Then we identify possible configurations in which
all actuators for actuating the manipulator linkage are
ground-mounted. The distinct advantage of being able to
put many actuators on the ground makes these manipulator
topologies appealing.
Degrees of freedom. In general, the mobility of a
kinematic chain can be obtained from the Kutzbach criterion.
The six-dimensional form of the criterion is given as
m = 6(n 1) 5j1 4j2 3j3 2j4 J5 (2.1)
where m = mobility of mechanism,
n = number of links,
ji = number of joints having i degrees of freedom.