blockSecondOrder
Second order (continuous or discrete) transfer function block (= 2 poles)
Extends from Interfaces.PartialSISO2 (Partial Single Input Single Output (continuous or discrete) control block of Controller library).
Information
This blocks defines the transfer function between the input u and the output y as second order system:
k
y = --------------------------------- * u
( s / w )^2 + 2*D*( s / w ) + 1
The block can be continuous or discrete (with continuous parameterization).
If you would like to be able to change easily between different
transfer functions (FirstOrder, SecondOrder, ... ) by changing
parameters, use the general model class TransferFunction
instead and model a second order SISO system with parameters
n = {k}, d = {1/w^2, 2*D/w, 1}.
Example
parameter: k = 0.3, w = 0.5, D = 0.4
results in
0.3
y = ------------------- * u
4.0 s^2 + 1.6 s + 1
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | continuous (from PartialSampledBlock) | blockType == Types.BlockTypeWithGlobalDefault.Continuous or blockType == Types.BlockTypeWithGlobalDefault.UseSampleClockOption and sampleClock.blockType == Types.BlockType.Continuous | True, if continuous block, otherwise discrete block |
| Types.Init | init (from PartialSampledBlock) | Modelica_LinearSystems2.Controllers.Internal.convertToInit(initType, sampleClock.initType) | Type of initialization (no init/steady state/initial state/initial output) |
| Real | k | 1 | Gain |
| Real | w | 1 | Angular frequency |
| Real | D | 1 | Damping |
| Advanced options | |||
| Types.BlockTypeWithGlobalDefault | blockType (from PartialSampledBlock) | Modelica_LinearSystems2.Controllers.Types.BlockTypeWithGlobalDefault.UseSampleClockOption | Type of block |
| Types.InitWithGlobalDefault | initType (from PartialSampledBlock) | Types.InitWithGlobalDefault.UseSampleClockOption | Type of initialization (no init/steady state/initial state/initial output) |
| Real | y_start | 0.0 | Initial or guess value of output (= state) |
| Real | yd_start | 0.0 | Initial or guess value of derivative of output (= state) |
| Advanced options › Discrete block parameters | |||
| Types.MethodWithGlobalDefault | methodType (from PartialSampledBlock) | Types.MethodWithGlobalDefault.UseSampleClockOption | Type of discretization if discrete block |
| Integer | sampleFactor (from PartialSampledBlock) | 1 | Sample factor (Ts = sampleFactor * sampleClock.sampleTime) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | u (from PartialSISO2) | Continuous or discrete input signal of block | |
| Modelica.Blocks.Interfaces.RealOutput | y (from PartialSISO2) | Continuous or discrete output signal of block | |
| Modelica.Blocks.Interfaces.RealOutput | yd | First derivative of y | |
| Modelica.Blocks.Interfaces.RealOutput[2] | yy | {y, yd} |