sdo.requirements.PZNaturalFrequency

Natural frequency bound

Description

Specify bounds on the natural frequency of the poles of a linear system. You can then optimize the model response to meet these bounds using sdo.optimize.

You must have Simulink^® Control Design™ software to specify natural frequency requirements.

Creation

Syntax

pznatfreq_req = sdo.requirements.PZNaturalFrequency

pznatfreq_req = sdo.requirements.PZNaturalFrequency(Name=Value)

Description

pznatfreq_req = sdo.requirements.PZNaturalFrequency creates a sdo.requirements.PZNaturalFrequency object and assigns default values to its properties.

pznatfreq_req = sdo.requirements.PZNaturalFrequency(Name=Value) specifies one or more properties using name-value arguments. For example, pznatfreq_req = sdo.requirements.PZNaturalFrequency(FrequencyUnits="Hz") creates an sdo.requirements.PZNaturalFrequency object and specifies the FrequencyUnits property as hertz.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes. For example, pznatfreq_req = sdo.requirements.PZNaturalFrequency("FrequencyUnits","Hz") creates an sdo.requirements.PZNaturalFrequency object and specifies the FrequencyUnits property as hertz.

Properties

Description — Requirement description

'' (default) | character vector

Requirement description, specified as a character vector.

Example: 'Requirement on signal 1'

FrequencyUnits — Frequency units

"rad/s" (default) | string scalar | character vector

Frequency units of the requirement, specified as one of the following. The PZNaturalFrequency object stores the value as a character vector.

• "Hz"

• "rad/s"

• "rpm"

• "kHz"

• "MHz"

• "GHz"

• "rad/nanosecond"

• "rad/microsecond"

• "rad/millisecond"

• "rad/minute"

• "rad/hour"

• "rad/day"

• "rad/week"

• "rad/month"

• "rad/year"

• "cycles/nanosecond"

• "cycles/microsecond"

• "cycles/millisecond"

• "cycles/hour"

• "cycles/day"

• "cycles/week"

• "cycles/month"

• "cycles/year"

Name — Requirement name

'' (default) | character vector

Requirement name, specified as a character vector.

NaturalFrequency — Natural frequency bound

2 (default) | positive finite scalar

Natural frequency bound, in radians/second, specified as a positive finite scalar.

Type — Natural frequency bound type

">=" (default) | ">=""==" | "max"

Natural frequency bound type, specified as one of the following values:

• "<=" — Upper bound

• ">=" — Lower bound

• "==" — Equality bound

• "max" — Maximization objective

Object Functions

copy	Copy design requirement
get	Get design requirement property values
set	Set design requirement property values
evalRequirement	Evaluate design requirement

Examples

Create Natural Frequency Object

Create a natural frequency object and then specify the natural frequency.

r = sdo.requirements.PZNaturalFrequency;
r.NaturalFrequency = 1;

Alternatively, you can specify the natural frequency when you create the object.

r = sdo.requirements.PZNaturalFrequency(NaturalFrequency=1)

r = 
  PZNaturalFrequency with properties:

    NaturalFrequency: 1
                Type: '>='
                Name: ''
         Description: ''
      FrequencyUnits: 'rad/s'

Alternatives

Use getbounds to get the bounds specified in a Check Pole-Zero Characteristics (Simulink Control Design) block.

Version History

Introduced in R2010b