Robotics lll

UNIT 3
PAG. 3
The goal of an IK element (i.e.
resolution of an IK element) is to
have the target followed by the
tip (i.e. having tip and target
overlap, given certain
constraints), by computing the
appropriate joint values for the
kinematic chain:
[Two kinematic chains, each describing an IK element]
[IK element and corresponding model of the IK solving task]
In above example (in 2D for simplicity), we can
specify various constraints for the tip-target pair,
e.g.:
• X positional constraint: the tip would follow the
target only on the X-axis, and the kinematic chain
would appear redundant for this task since the
chain itself has 3 Degrees of Freedom (DoFs).
• X/Y positional constraints: the tip would follow the
target only in position, and the kinematic chain
would still appear redundant for this task.
• X/Y positional + Θ orientational constraints: the
tip would follow the target in position and
orientation, and the kinematic chain would not
appear as redundant anymore for this task.
Note that even for the most basic IK task, an IK
element is solved via the resolution of the
encompassing IK group.
Two separate kinematic chains are handled in an
identical fashion, however this time, two IK groups
are needed (and each one of them should contain
one IK element for each kinematic chain). Solving
order of the two IK groups is usually not important:
Salvador SLIDESMANIA.COM
Pintor Castillo