10.13.1. Force Definition
All forces that are include applied forces and joint reaction forces written with respect to user defined reference frame. If a selected body is base body of joint or forces, torque arm is considered to acting torque.
Action Body
The magnitude of force is acting on the action body at the action marker position with respect to reference marker.
\(\mathbf{F}={{({{\mathbf{A}}_{r}}{{\mathbf{C}}_{r}})}^{T}}{{\mathbf{f}}_{a}}\)
\(\mathbf{T}={{({{\mathbf{A}}_{r}}{{\mathbf{C}}_{r}})}^{T}}{{\boldsymbol{\tau }}_{a}}\)
Base Body
The magnitude of force is acting on the action body at the action marker position with respect to reference marker. Reaction torque considers torque arm effect.
\(\mathbf{F}=-{{({{\mathbf{A}}_{r}}{{\mathbf{C}}_{r}})}^{T}}{{\mathbf{f}}_{a}}\)
\(\mathbf{T}=-{{({{\mathbf{A}}_{r}}{{\mathbf{C}}_{r}})}^{T}}{{\boldsymbol{\tau }}_{a}}-{\tilde{\mathbf{d}}}_{ji}{{\mathbf{f}}_{a}}\)
Different Types
PTCV and CVCV
These joints interact with each other at the constrained position. So PTCV and CVCV constraint does not generate torque.