functionlimitByStriple
Returns a point-symmetric Triple S-Function
Extends from Modelica.Icons.Function (Icon for functions).
Information
Syntax
y = Functions.limitByStriple(x_max, x_sat, y_max, y_sat, x);
Description
A point symmetric interpolation between points (0, 0), (x_max, y_max) and (x_sat, y_sat), provided x_max < x_sat. The approximation is done in such a way that the 1st function's derivative is zero at points (x_max, y_max) and (x_sat, y_sat). Thus, the 1st function's derivative is continuous for all x. The higher derivatives are, in contrast, discontinuous at these points.
The figure below shows the function y and its 1st derivative dy/dx for the following input: x_max = 0.2, x_sat = 0.5, y_max = 1.4, y_sat = 1.2.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | x_max | Abscissa for y_max | |
| Real | x_sat | Abscissa for y_sat | |
| Real | y_max | Peak ordinate | |
| Real | y_sat | Saturated ordinate | |
| Real | x | Current abscissa value |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | y | Current ordinate |
Revisions
Developed 2010 at the DLR Institute of System Dynamics and Control