sdo.requirements.StepResponseEnvelope class

Package: sdo.requirements

Step response bound on signal

Description

Specify a step response envelope requirement on a time-domain signal. Step response characteristics such as rise-time and percentage overshoot define the step response envelope.

Construction

step_req = sdo.requirements.StepResponseEnvelope creates an sdo.requirements.StepResponseEnvelope object and assigns default values to its properties.

step_req = sdo.requirements.StepResponseEnvelope(Name,Value) uses additional options specified by one or more Name,Value pair arguments. Name is a property name and Value is the corresponding value. Name must appear inside single quotes (''). You can specify several name-value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Input Arguments

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

'Description'

Requirement description. Must be a string.

Default: ''

'FinalValue'

Final value of the step response. Must be a finite real scalar not equal to the InitialValue property.

Default: 1

'InitialValue'

Value of the signal level before the step response starts. Must be a finite real scalar not equal to the FinalValue. property.

Default: 0

'Name'

Requirement name. Must be a string.

Default: ''

'PercentOvershoot'

The percentage amount by which the signal can exceed the final value before settling.

Must be a real finite scalar between [0 100] and greater than PercentSettling.

Use set to set this and the PercentSettling properties simultaneously.

Default: 10

'PercentRise'

The percentage of final value used with the RiseTime property to define the overall rise time characteristics.

Must be a real finite scalar between [0 100] and less than (100–PercentSettling).

Use set to set this and the PercentSettling properties simultaneously.

Default: 80

'PercentSettling'

The percentage of the final value that defines the settling range of settling time characteristic specified in the SettlingTime property.

Must be a real positive finite scalar between [0 100] and less than (100 – PercentRise) and less than PercentOvershoot.

Use set to set this and the PercentOvershoot and PercentRise properties simultaneously.

Default: 1

'PercentUndershoot'

The percentage amount by which the signal can undershoot the initial value.

Must be a positive finite scalar between [0 100].

Default: 1

'RiseTime'

Time taken, in seconds, for the signal to reach a percentage of the final value specified in PercentRise.

Must be a finite positive real scalar and less than the SettlingTime. Time is relative to the StepTime.

Use set to set this and the StepTime and SettlingTime properties simultaneously.

Default: 5

'SettlingTime'

Time taken, in seconds, for the signal to settle within a specified range around the final value. This settling range is defined as the final value plus or minus the percentage of the final value, specified in PercentSettling.

Must be a finite positive real scalar, greater than RiseTime. Time is relative to the StepTime.

Use set to set this and the RiseTime properties simultaneously.

Default: 7

'StepTime'

Time, in seconds, when the step response starts.

Must be a finite real nonnegative scalar, less than the RiseTime property.

Use set to set this and the RiseTime properties simultaneously.

Default: 0

'TimeUnits'

Time units of the requirement. Must be one of the following strings:

  • 'nanoseconds'

  • 'microseconds'

  • 'milliseconds'

  • 'seconds'

  • 'minutes'

  • 'hours'

  • 'days'

  • 'weeks'

  • 'months'

  • 'years'

Default: 'second'

'Type'

Step response bound type.

This property is read-only and set to '<='.

Properties

Description

Requirement description. Must be a string.

Default: ''

FinalValue

Final value of the step response. Must be a finite real scalar not equal to the InitialValue property.

Default: 1

InitialValue

Value of the signal level before the step response starts. Must be a finite real scalar not equal to the FinalValue. property.

Default: 0

Name

Requirement name. Must be a string.

Default: ''

PercentOvershoot

The percentage amount by which the signal can exceed the final value before settling.

Must be a real finite scalar between [0 100] and greater than PercentSettling.

Use set to set this and the PercentSettling properties simultaneously.

Default: 10

PercentRise

The percentage of final value used with the RiseTime property to define the overall rise time characteristics.

Must be a real finite scalar between [0 100] and less than (100–PercentSettling).

Use set to set this and the PercentSettling properties simultaneously.

Default: 80

PercentSettling

The percentage of the final value that defines the settling range of settling time characteristic specified in the SettlingTime property.

Must be a real positive finite scalar between [0 100] and less than (100 – PercentRise) and less than PercentOvershoot.

Use set to set this and the PercentOvershoot and PercentRise properties simultaneously.

Default: 1

PercentUndershoot

The percentage amount by which the signal can undershoot the initial value.

Must be a positive finite scalar between [0 100].

Default: 1

RiseTime

Time taken, in seconds, for the signal to reach a percentage of the final value specified in PercentRise.

Must be a finite positive real scalar and less than the SettlingTime. Time is relative to the StepTime.

Use set to set this and the StepTime and SettlingTime properties simultaneously.

Default: 5

SettlingTime

Time taken, in seconds, for the signal to settle within a specified range around the final value. This settling range is defined as the final value plus or minus the percentage of the final value, specified in PercentSettling.

Must be a finite positive real scalar, greater than RiseTime. Time is relative to the StepTime.

Use set to set this and the RiseTime properties simultaneously.

Default: 7

StepTime

Time, in seconds, when the step response starts.

Must be a finite real nonnegative scalar, less than the RiseTime property.

Use set to set this and the RiseTime properties simultaneously.

Default: 0

TimeUnits

Time units of the requirement. Must be one of the following strings:

  • 'nanoseconds'

  • 'microseconds'

  • 'milliseconds'

  • 'seconds'

  • 'minutes'

  • 'hours'

  • 'days'

  • 'weeks'

  • 'months'

  • 'years'

Default: 'second'

Type

Step response bound type.

This property is read-only and set to '<='.

Methods

evalRequirementEvaluate step response bound

Copy Semantics

Handle. To learn how handle classes affect copy operations, see Copying Objects in the MATLAB® documentation.

Examples

Construct a step response bound object and specify percent overshoot.

 r = sdo.requirements.StepResponseEnvelope;
 r.PercentOvershoot = 20;

Alternatively, you can specify the percent overshoot during construction:

 r = sdo.requirements.StepResponseEnvelope('PercentOvershoot',20);

Alternatives

Use getbounds to get the bounds specified in a Check Step Response Characteristics block.

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