Rigid Body Frame
A frame with a fixed displacement and orientation relative to a rigid body center of mass (CoM) frame
A Rigid Body Frame is a body-fixed frame that is used to define locations of interest on the body where it is connected (for example, locations where it connects to other bodies). The position and orientation relative to the center of mass must be defined for each body-fixed frame.
The position of the body-fixed x'y'z' frame relative to the center of mass xyz frame, both shown in the diagram below, is defined by the translational position vector from C to P, resolved into components along the center of mass x,y, and z axes. The orientation of x'y'z' with respect to xyz can be defined by the rotation transformation matrix between the two, or by a rotation about one or more of the x, y, or z axes.
Connections
Parameters
See Also
Name
Description
framea
Base of rigid body frame. This should be attached to a rigid body center of mass frame.
frameb
Tip of rigid body frame
Symbol
Default
Units
Modelica ID
r&conjugate0;XYZ
100
m
The x,y,z offset of the outboard frame with respect to the inboard frame
InitPos
TypeR
Euler Angles
Indicates whether the rotation matrix, R&conjugate0;, or the rotation sequence, θ&conjugate0;ζ,η,ξ, is used to express the orientation of the outboard frame with respect to the inboard frame
RSelect
R
100010001
The rotation matrix that transforms a vector expressed in the outboard frame to the inboard frame
RMat
Typeθ
123
Indicates the sequence of subsequent rotations describing the orientation of the outboard frame with respect to the inboard frame. For example, 1,2,3 refers to sequential rotations about the x, then y, then z axis (123 - Euler angles)
RotType
θ&conjugate0;ζ,η,ξ
000
rad
Rotations about the axes selected in Typeθ
InitAng
Bodies and Frames
Multibody Overview
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