WOLFRAM SYSTEM MODELER
DemoSignalCharacteristicDemonstrate characteristic values of a signal |
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Diagram
Wolfram Language
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SystemModel["Modelica.Blocks.Examples.DemoSignalCharacteristic"]
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Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This example demonstrates how to calculate characteristic values of the pulse signal y
| Characteristic quantity | Numerically calculated | Analytically calculated |
| Mean | mean.y |
y_mean |
| Rectified mean | rectifiedMean.y |
y_rect |
| Root mean square | rootMeanSquare.y |
y_rms |
| First harmonic | harmonic.y_rmsharmonic.y_arg |
y1_rmsy1_arg |
The output of these blocks is updated after each period of the signal.
Using a simple pulse series, these values can be calculated analytically. Propagating these values as initial values for the output, we can compare the numerical solution with the analytical solution: The output is constant from the beginning.
Parameters (11)
| app |
Value: 1 Type: Real Description: Peak-to-peak value of pulse signal |
|---|---|
| dutyCycle |
Value: 0.5 Type: Real Description: Duty cycle of pulse signal |
| offset |
Value: 0 Type: Real Description: Offset of pulse signal |
| f |
Value: 50 Type: Frequency (Hz) Description: Base frequency of pulse signal |
| y_mean |
Value: offset + app * dutyCycle Type: Real Description: Mean value |
| y_rect |
Value: abs(offset + app) * dutyCycle + abs(offset) * (1 - dutyCycle) Type: Real Description: Rectified mean |
| y_rms |
Value: sqrt((offset + app) ^ 2 * dutyCycle + offset ^ 2 * (1 - dutyCycle)) Type: Real Description: Root mean square |
| y1_cos |
Value: ((offset + app) * (sin(dutyCycle * 2 * pi) - sin(0)) + offset * (sin(2 * pi) - sin(dutyCycle * 2 * pi))) / pi / sqrt(2) Type: Real Description: First harmonic cosine rms component |
| y1_sin |
Value: ((offset + app) * (-cos(dutyCycle * 2 * pi) + cos(0)) + offset * (-cos(2 * pi) + cos(dutyCycle * 2 * pi))) / pi / sqrt(2) Type: Real Description: First harmonic sine rms component |
| y1_rms |
Value: sqrt(y1_cos ^ 2 + y1_sin ^ 2) Type: Real Description: RMS value of first harmonic |
| y1_arg |
Value: atan2(y1_sin, y1_cos) Type: Real Description: Argument of first harmonic |
Components (5)
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pulse |
Type: Pulse Description: Generate pulse signal of type Real |
|---|---|---|
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mean |
Type: Mean Description: Calculate mean over period 1/f |
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rectifiedMean |
Type: RectifiedMean Description: Calculate rectified mean over period 1/f |
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rootMeanSquare |
Type: RootMeanSquare Description: Calculate root mean square over period 1/f |
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harmonic |
Type: Harmonic Description: Calculate harmonic over period 1/f |