Equivalent motor mass

Introduced in MORe v3.1

Represents an additional motor inertia. Can be used to model the rotor inertia without explicitly modeling it in FEM.

Block diagram

Signal	Description
\(u_f\)	Filter output
\(u_v\)	Coupling link velocity
\(u_x\)	Coupling link position
\(v_{fb}\)	Motor velocity. Can be used as feedback in architecture.
\(x_{fb}\)	Motor position. Can be used as feedback in architecture.
\(y\)	Motor output. Force acting on coupling link.

Parameter

Variable	Units linear	Units rotary	Description
Stiffness	\(N/m\)	\(Nm/rad\)	Coupling stiffness
Damping	\(N s/m\)	\(Nm s/rad\)	Coupling damping
Inertia	\(kg\)	\(kg m^2\)	Rotor Inertia
Spindle pitch	\(-\)	\(m\)	Ballscrew spindle pitch. [1]

[1]

Used in postprocessor to allow for scaling of the error only. Scales setpoints to linear axis movement.

\(x_{lin} = x_{rot} \frac{hs}{2 \pi}\)

Coupling

Link selection to represent the motor. The controller output (force/torque) will be applied to the selected link.