blockDerivative

Approximate derivative (continuous or discrete block)

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 approximative derivative (DT1):

             k * s
     y = ------------ * u
            T * s + 1

The block can be continuous or discrete (with continuous parameterization).

If k=0, the state space realization of the block is specially constructed, in order that the D-part of PID controllers can be set to zero without introducing numerical problems.

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 DT1 system with parameters
n = {k,0}, d = {T,1}.

Parameters

TypeNameDefaultDescription
Booleancontinuous (from PartialSampledBlock)blockType == Types.BlockTypeWithGlobalDefault.Continuous or blockType == Types.BlockTypeWithGlobalDefault.UseSampleClockOption and sampleClock.blockType == Types.BlockType.ContinuousTrue, if continuous block, otherwise discrete block
Types.Initinit (from PartialSampledBlock)Modelica_LinearSystems2.Controllers.Internal.convertToInit(initType, sampleClock.initType)Type of initialization (no init/steady state/initial state/initial output)
Realk1Gain
Modelica.Units.SI.TimeT0.01Time Constant (T>0 required; T=0 is ideal derivative block)
Advanced options
Types.BlockTypeWithGlobalDefaultblockType (from PartialSampledBlock)Modelica_LinearSystems2.Controllers.Types.BlockTypeWithGlobalDefault.UseSampleClockOptionType of block
Types.InitWithGlobalDefaultinitType (from PartialSampledBlock)Types.InitWithGlobalDefault.UseSampleClockOptionType of initialization (no init/steady state/initial state/initial output)
Realx_start0Initial or guess value of state
Realy_start0Initial or guess value of output
Advanced options › Discrete block parameters
Types.MethodWithGlobalDefaultmethodType (from PartialSampledBlock)Types.MethodWithGlobalDefault.UseSampleClockOptionType of discretization if discrete block
IntegersampleFactor (from PartialSampledBlock)1Sample factor (Ts = sampleFactor * sampleClock.sampleTime)

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.RealInputu (from PartialSISO2)Continuous or discrete input signal of block
Modelica.Blocks.Interfaces.RealOutputy (from PartialSISO2)Continuous or discrete output signal of block
Modelica.Blocks.Interfaces.RealOutputxState of approximative derivative