modelSpeed
Forced movement of a flange according to a reference angular velocity signal
Extends from Modelica.Mechanics.Rotational.Interfaces.PartialElementaryOneFlangeAndSupport2 (Partial model for a component with one rotational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models).
Information
The input signal w_ref defines the reference speed in [rad/s]. Flange flange is forced to move relative to flange support according to this reference motion. According to parameter exact (default = false), this is done in the following way:
- 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. - exact=false
The reference angle is filtered and the second derivative of the filtered curve is used to compute the reference acceleration of the flange. This second 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 generator blocks of the block library Modelica.Blocks.Sources.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | useSupport (from PartialElementaryOneFlangeAndSupport2) | false | = true, if support flange enabled, otherwise implicitly grounded |
| Boolean | exact | false | Is true/false for exact treatment/filtering of the input signal, respectively |
| SI.Frequency | f_crit | 50 | If exact=false, critical frequency of filter to filter input signal |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Flange_b | flange (from PartialElementaryOneFlangeAndSupport2) | Flange of shaft | |
| Support | support (from PartialElementaryOneFlangeAndSupport2) | Support/housing of component | |
| Modelica.Blocks.Interfaces.RealInput | w_ref | Reference angular velocity of flange with respect to support as input signal |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Angle | phi | Rotation angle of flange with respect to support | |
| SI.AngularVelocity | w | Angular velocity of flange with respect to support | |
| SI.AngularAcceleration | a | If exact=false, angular acceleration of flange with respect to support else dummy |