LimIntegrator
Integrator with limited value of the output and optional reset
Library
Modelica/Blocks/Continuous
Description
This blocks computes y as integral of the input u multiplied with the gain k. If the integral reaches a given upper or lower limit and the input will drive the integral outside of this bound, the integration is halted and only restarted if the input drives the integral away from the bounds.
It might be difficult to initialize the integrator in steady state. This is discussed in the description of package Continuous.
If parameter limitAtInit = false, the limits of the integrator are removed from the initialization problem which leads to a much simpler equation system. After initialization has been performed, it is checked via an assert whether the output is in the defined limits. For backward compatibility reasons limitAtInit = true. In most cases it is best to use limitAtInit = false.
If the reset port is enabled, then the output y is reset to set or to y_start (if the set port is not enabled), whenever the reset port has a rising edge.
Parameters
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_k | k | Integrator gain | Scalar | |
mo_outMax | outMax | Upper limit of output | Scalar | |
mo_outMin | outMin | Lower limit of output | Scalar | |
mo_use_reset | use_reset | =true, if reset port enabled | Number | 0 |
mo_use_set | use_set | =true, if set port enabled and used as reinitialization value when reset | Number | 0 |
mo_initType | initType | Type of initialization (1: no init, 2: steady state, 3/4: initial output) | Structure | |
mo_initType/choice1 | No initialization (start values are used as guess values with fixed=false) | Number | 0 | |
mo_initType/choice2 | Steady state initialization (derivatives of states are zero) | Number | 0 | |
mo_initType/choice3 | Initialization with initial states | Number | 0 | |
mo_initType/choice4 | Initialization with initial outputs (and steady state of the states if possible) | Number | 0 | |
mo_limitsAtInit | limitsAtInit | = false, if limits are ignored during initialization (i.e., der(y)=k*u) | Scalar | true |
mo_y_start | y_start | Initial or guess value of output (must be in the limits outMin .. outMax) | Scalar |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_strict | strict | = true, if strict limits with noEvent(..) | Scalar | true |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_u | u | u | Structure | |
mo_u/fixed | fixed | Cell of scalars | true | |
mo_u/start | start | Cell of scalars | ||
mo_y | y | y | Structure | |
mo_y/fixed | fixed | Cell of scalars | true | |
mo_y/start | start | Cell of scalars | ||
mo_reset | reset | reset | Structure | |
mo_reset/fixed | fixed | Cell of scalars | true | |
mo_reset/start | start | Cell of scalars | ||
mo_set | set | set | Structure | |
mo_set/fixed | fixed | Cell of scalars | true | |
mo_set/start | start | Cell of scalars |
Ports
| Name | Type | Description | IO Type | Number |
|---|---|---|---|---|
u | implicit | Connector of Real input signal | input | 1 |
y | implicit | Connector of Real output signal | output | 1 |
Port 3 | implicit | Optional connector of reset signal | input | mo_use_reset |
Port 4 | implicit | Optional connector of set signal | input | mo_use_reset&&mo_use_set |