Universal

A universal joint creates a frame that is rotated relative to an existing frame using a two angles to define its orientation.

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 translational and rotational displacement components are defined

param str rotation_pair

‘XY’, ‘YX’, ‘YZ’, ‘ZY’, ‘ZX’, or ‘XZ’, represents a two angle rotation sequence

Initial Values

param numeric initial_r0

Initial value for the 0^{th} rotation angle in the Euler sequence

param numeric initial_r1

Initial value for the 1^{st} rotation angle in the Euler sequence

param numeric rate_r0

Initial value for angular rotation rate of the 0^{th} angle

param numeric rate_r1

Initial value for angular rotation rate of the 1^{st} angle

If the DOF form is chosen, then optional stiffness, damping, and equilibrium coefficients can be used to include rotational spring-damper physics in the joint.

Spring Parameters

param numeric kr0

Stiffness corresponding to the 0^{th} rotation angle in the Euler sequence

param numeric kr1

Stiffness corresponding to the 1^{st} rotation angle in the Euler sequence

param numeric cr0

Damping corresponding to the angular rotation rate about the x-axis of the created frame

param numeric cr1

Stiffness corresponding to the angular rotation rate about the y-axis of the created frame

param numeric equilibrium_r0

Equilibrium corresponding to the 0^{th} rotation angle in the Euler sequence

param numeric equilibrium_r1

Equilibrium corresponding to the 1^{st} rotation angle in the Euler sequence