All actuation, except for initial conditions, requires physical signal inputs to define time-varying functions that carry physical units.
Torque-force actuation and motion actuation are complementary and mutually exclusive. In all cases, exercise care as you apply a mixture of actuation types to a driveline and its degrees of freedom (DoFs). The complete effect of the actuation types must be such that:
Driveline DoFs actuated by torques and forces are not also subject to motion actuation. (They can be subject to motion initial condition settings.)
Driveline DoFs actuated by motions are not also subject to torque or force actuation.
For a Simscape™ Driveline™ model to simulate nontrivial motion, torque and motion actuation types complement one another exactly to account consistently for the motion of all the DoFs. If this criterion is not satisfied, one of these outcomes results:
The motion of the driveline is trivial, staying in its initial motion state for the entire simulation.
The actuation types are inconsistent with each other, and the simulation stops with an error.
The actuation types leave the driveline motion underdetermined or overdetermined, and the simulation stops with an error.
For more information, see Troubleshoot Driveline Modeling and Simulation Issues.