Joint where frame_b is translated along axis n which is fixed in frame_a.
The two frames coincide when "s + s_offset = 0", where
"s_offset" is a parameter with a zero default
and "s" is the relative distance.
This variant of the prismatic joint is designed to work together
with a length constraint in a kinematic loop. This means that the
relative distance "s" of the joint is computed such that the
length constraint is fulfilled.
Usually, this joint should not be used by a user of the MultiBody
library. It is only provided to built-up the Modelica.Mechanics.MultiBody.Joints.Assemblies.JointXYZ
joints.
In releases before version 3.0 of the Modelica Standard Library, it was possible
to activate the force projection equation (= cut-force projected to the translation
axis must be identical to the driving force of flange axis) via parameter
axisForceBalance. This is no longer possible, since otherwise this
model would not be "balanced" (= same number of unknowns as equations).
Instead, when using this model in version 3.0 and later versions,
the force in the length constraint component (Joints.SphericalSpherical or
Joints.UniversalSpherical) must be calculated such that the driving force
in direction of the translation
axis is (RC shall be the name of the instance of PrismaticWithLenghtConstraint):
0 = RC.axis.f + RC.e*RC.frame_b.f;
If this equation is used, usually the force in the length constraint
and the second derivative of the prismatic distance will be part of a linear
algebraic system of equations. In some cases it is possible to solve
this system of equations locally, i.e., provide the rod force directly
as function of the prismatic constraint force. In any case, this projection
equation or an equivalent one has to be provided via variable "constraintResidue" in the "Advanced"
menu of "Joints.SphericalSpherical" or "Joints.UniversalSpherical".
CONNECTORS
