Prismatic

A prismatic joint creates a point that is translated relative to an existing point with vector components defined in a specified reference frame. The joint is analogous to creating a vector and point using the classic interface. The vector component can be constant valued, or a degree of freedom (DOF) may be generated where the point can translate in the unit vector direction. If the DOF form is chosen, then an optional linear stiffness, damping, and equilibrium distance can be used to include translational spring-damper physics in the joint.

Keyword Arguments

param str name

Name given to the joint, default is uppercase characters in alphabetical order (A, B, C, …)

param str ref_point_key

Start point from which the vector component of the joint is defined

param str ref_frame_key

Reference frame in which the components of the vector are defined, with basis vectors e_x, e_y, and e_z

param str is_form

‘constant’ or ‘degree of freedom’

Vector Components

param numeric x

Component of the unit vector measured in the x-axis of the reference frame

param numeric y

Component of the unit vector measured in the y-axis of the reference frame

param numeric z

Component of the unit vector measured in the z-axis of the reference frame

Initial States

param numeric value

Initial value for the generalized coordinate if is_form == ‘degree of freedom’

param numeric rate

Initial value for the generalized speed if is_form == ‘degree of freedom’

Spring Parameters

param numeric k

Spring constant

param numeric c

Damping constant

param numeric equilibrium

Equilibrium distance

return str

Message describing the inputs used in creation of the joint