Speed

Forced movement of a flange according to a reference speed

    Speed

Library

Modelica/Mechanics/Translational/Sources

Description

The input signal v_ref defines the referencespeed in [m/s]. Flange flange is forcedto move relative to the support connector according to this reference motion. According to parameterexact (default = false), this is done in the following way:

  1. exact=true
    The reference speed is treated exactly. This is only possible, if the input signal is defined by an analytical function which can be differentiated at least once. If this prerequisite is fulfilled, the Modelica translator will differentiate the input signal once in order to compute the reference acceleration of the flange.
  2. exact=false
    The reference speed is filtered and the first derivative of the filtered curve is used to compute the reference acceleration of the flange. This first derivative is not computed by numerical differentiation but by an appropriate realization of the filter. For filtering, a first order filter is used. The critical frequency (also called cut-off frequency) of the filter is defined via parameter f_crit in [Hz]. This value should be selected in such a way that it is higher as the essential low frequencies in the signal.

The input signal can be provided from one of the signal generatorblocks of the block library Modelica.Blocks.Sources.

Parameters

Speed_0

NameLabelDescriptionData TypeValid Values

mo_useSupport

useSupport

= true, if support flange enabled, otherwise implicitly grounded

Number

0
1

mo_exact

exact

Is true/false for exact treatment/filtering of the input signal, respectively

Scalar

true
false

mo_f_crit

f_crit

If exact=false, critical frequency of filter to filter input signal

Scalar

mo_w_crit

w_crit

Critical frequency

Scalar

mo_s

s

s

Structure

mo_s/fixed

fixed

Cell of scalars

true
false

mo_s/start

start

Cell of scalars

Speed_1

NameLabelDescriptionData TypeValid Values

mo__nmodifiers

Number of Modifiers

Specifies the number of modifiers

Number

mo__modifiers

Modifiers

Add new modifier

Structure

mo__modifiers/varname

Variable name

Cell of strings

's_support'
'v'
'a'

mo__modifiers/attribute

Attribute

Cell of strings

'start'
'fixed'

mo__modifiers/value

Value

Ports

NameTypeDescriptionIO TypeNumber

flange

implicit

Flange of component

output

1

v_ref

implicit

Reference speed of flange as input signal

input

1

Port 3

implicit

Support/housing of component

input

mo_useSupport

See Also