Designs based on Parallel Robotic Manipulators
Parallel Manipulators are mechanisms whose end effector and base are connected
by more than one link. The simplest parallel manipulator is the four bar
linkage.The two figures given above are also examples of parallel manipulators.
The left figure is a six degree of freedom called the Stewart Platform.
The Parallel Manipulators are in general more rigid than serial manipulators
and display a higher degree of accuracy. Parallel Structures like the Stewart
Platform or three limbed spatial mechanisms display very high stiffness
for very small masses. Moreover their positioning accuracy is quite high.
These characteristics of parallel manipulators make them suitable
for machine tool applications. Manipulators which have raised particular
interest for machine tool applications are 3 degree of freedom parallel
spatial structures, the Stewart Platform and other 6 degree of freedom
Unlike the serial manipulators, parallel manipulators have very
simple inverse kinematics but tougher direct kinematics.