The Translational Speed (or Speed) component generates a forced translational speed according to an input signal, $v_{\mathrm{ref}}$

The $\mathrm{Exact}$ boolean parameter determine how $v_{\mathrm{ref}}$ is used:

When $\mathrm{Exact}$ is true, $v_{\mathrm{ref}}$ is used as-is. The input signal must be differentiable.

When $\mathrm{Exact}$ is false (the default), $v_{\mathrm{ref}}$ is filtered and the derivative of the filtered curve is used to compute the reference acceleration of the flange. This derivative is not computed by numerical differentiation but rather by a first-order filter. The critical frequency (cut-off frequency) of the filter is defined by the parameter $f_{\mathrm{crit}}$, which should be higher than the essential low frequencies in the signal.

The Use Support Flange boolean parameter enables a support flange on the housing. When true (checked) the support flange must be connected in the drawing. When false the component is internally fixed to ground.

$\{\begin{array}{cc}\left\{a\=0\,v\=v_{\mathrm{ref}}\right\}& \mathrm{Exact}\\ \left\{a\=\left(v_{\mathrm{ref}}-v\right)v_{\mathrm{crit}}\,a\=\stackrel{\.}{v}\right\}& \mathrm{otherwise}\end{array}$

$w_{\mathrm{crit}}\=2\mathrm{\pi }{f}_{\mathrm{crit}}$

$v\=\stackrel{\.}{s}$

$\mathbf{if}\mathrm{Use\; Support\; Flange}\mathbf{then}{f}_{\mathrm{support}}\=-f$

$s\=s_{\mathrm{flange}}-\{\begin{array}{cc}{s}_{\mathrm{support}}& \mathrm{Use\; Support}\\ 0& \mathrm{otherwise}\end{array}$

The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.