SecondOrder

Second order transfer function block (= 2 poles)

    SecondOrder

Library

Modelica/Blocks/Continuous

Description

This blocks defines the transfer function between the input u andthe output y as second order system:

                             k     y = ---------------------------------------- * u            ( s / w )^2 + 2*D*( s / w ) + 1

If you would like to be able to change easily between differenttransfer functions (FirstOrder, SecondOrder, ... ) by changingparameters, use the general model class TransferFunctioninstead and model a second order SISO system with parameters
b = {k}, a = {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

SecondOrder_0

NameLabelDescriptionData TypeValid Values

mo_k

k

Gain

Scalar

mo_w

w

Angular frequency

Scalar

mo_D

D

Damping

Scalar

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
1

mo_initType/choice2

Steady state initialization (derivatives of states are zero)

Number

0
1

mo_initType/choice3

Initialization with initial states

Number

0
1

mo_initType/choice4

Initialization with initial outputs (and steady state of the states if possible)

Number

0
1

mo_y_start

y_start

Initial or guess value of output (= state)

Scalar

mo_yd_start

yd_start

Initial or guess value of derivative of output (= state)

Scalar

mo_yd

yd

yd

Structure

mo_yd/fixed

fixed

Cell of scalars

true
false

mo_yd/start

start

Cell of scalars

SecondOrder_1

NameLabelDescriptionData TypeValid Values

mo__nmodifiers

Number of Modifiers

Specifies the number of modifiers

Number

mo__modifiers

Modifiers

Add new modifier

Structure

mo__modifiers/varname

Variable name

Cell of strings

mo__modifiers/attribute

Attribute

Cell of strings

'start'
'fixed'

mo__modifiers/value

Value

Ports

NameTypeDescriptionIO TypeNumber

u

implicit

Connector of Real input signal

input

1

y

implicit

Connector of Real output signal

output

1

See Also