VariableLimiter

Limit the range of a signal with variable limits

    VariableLimiter

Library

Blocks/Nonlinear

Description

The Limiter block passes its input signal as output signal as long as the input is within the upper and lower limits specified by the two additional inputs limit1 and limit2. If this is not the case, the corresponding limit is passed as output.

The parameter homotopyType in the Advanced tab specifies the simplified behaviour if homotopy-based initialization is used:

  • NoHomotopy: the actual expression with limits is used
  • Linear: a linear behaviour y = u is assumed (default option)
  • Fixed: it is assumed that the output is fixed at the value ySimplified

If it is known a priori in which region the input signal will be located, this option can help a lot by removing one strong nonlinearity from the initialization problem.

Parameters

VariableLimiter_0

NameLabelDescriptionData TypeValid Values

mo_homotopyType

homotopyType

Simplified model for homotopy-based initialization

Structure

mo_homotopyType/choice1

Simplified model = actual model

Number

0
1

mo_homotopyType/choice2

Simplified model: y = u

Number

0
1

mo_homotopyType/choice3

Simplified model: y = ySimplified

Number

0
1

VariableLimiter_1

NameLabelDescriptionData TypeValid Values

mo_strict

strict

= true, if strict limits with noEvent(..)

Scalar

true
false

mo_ySimplified

ySimplified

Fixed value of output in simplified model

Scalar

VariableLimiter_2

NameLabelDescriptionData TypeValid Values

mo_limitsAtInit

limitsAtInit

Has no longer an effect and is only kept for backwards compatibility (the implementation uses now the homotopy operator)

Scalar

true
false

VariableLimiter_3

NameLabelDescriptionData TypeValid Values

mo_u

u

u

Structure

mo_u/fixed

fixed

Cell of scalars

true
false

mo_u/start

start

Cell of scalars

mo_y

y

y

Structure

mo_y/fixed

fixed

Cell of scalars

true
false

mo_y/start

start

Cell of scalars

mo_limit1

limit1

limit1

Structure

mo_limit1/fixed

fixed

Cell of scalars

true
false

mo_limit1/start

start

Cell of scalars

mo_limit2

limit2

limit2

Structure

mo_limit2/fixed

fixed

Cell of scalars

true
false

mo_limit2/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

u

implicit

Connector of Real input signal

input

1

y

implicit

Connector of Real output signal

output

1

limit1

implicit

Connector of Real input signal used as maximum of input u

input

2

limit2

implicit

Connector of Real input signal used as minimum of input u

input

3