modelIntegratorVariableLimits
Extends from Modelica.Blocks.Interfaces.SISO (Single Input Single Output continuous control block).
Information
This blocks computes w as integral of the input u multiplied by the gain K.
If the integral reaches a given upper or lower limit, the integration is halted and only restarted if the input drives the integral away from the bounds, with a sufficient margin defined by Tol.
This margin is aimed at avoiding chattering i.e. rapid swings between frozen and unfrozen sates.
If the integration is halted, the integrator output follows the variable limit it has reached.
The output y is the result of the limitation of w by both variable limits.
If the "upper" limit is smaller than the "lower" one, the output y is ruled by the parameter DefaultLimitMax: y is equal to either limitMax or limitMin.
The integrator output is initialized with the parameter Y0.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | DefaultLimitMax | true | If limitMin > limitMax : if true, y = limitMax, if false, y = limitMin |
| Types.PerUnit | K | 1 | Integrator gain |
| Types.Time | tDer | 0.01 | Time constant of derivative filters for limits, in s |
| Types.PerUnit | Tol | Tolerance on limit crossing as a fraction of the difference between initial limits | |
| Types.PerUnit | LimitMax0 | Initial value of upper limit | |
| Types.PerUnit | LimitMin0 | Initial value of lower limit | |
| Types.PerUnit | Y0 | 0 | Initial or guess value of output |
| Boolean | FrozenMax0 | Y0 > LimitMax0 - Tol*abs(LimitMax0 - LimitMin0) | If true, integration is initially frozen at upper limit |
| Boolean | FrozenMin0 | Y0 < LimitMin0 + Tol*abs(LimitMax0 - LimitMin0) | If true, integration is initially frozen at lower limit |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| RealInput | u (from SISO) | Connector of Real input signal | |
| RealOutput | y (from SISO) | Connector of Real output signal | |
| Modelica.Blocks.Interfaces.RealInput | limitMax | Connector of Real input signal used as maximum of output y | |
| Modelica.Blocks.Interfaces.RealInput | limitMin | Connector of Real input signal used as minimum of output y |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Continuous.Derivative | derivativeLimitMax | ||
| Modelica.Blocks.Continuous.Derivative | derivativeLimitMin |