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SystemModelSustain

SystemModelSustain

SystemModelSustain[texpr,{min,max}]

is True over time intervals where texpr is True for at least min and at most max units of time.

Details

SystemModelSustain is typically used to filter out behaviors that are sustained for a certain amount of time. This is often useful for both safety and performance conditions.
SystemModelSustain[texpr,{min,max}][t] is True for if texpr[t] is True for and .

SystemModelSustain[texpr,{min,max}][t] is False otherwise.

SystemModelSustain can be used to specify system behaviors in functions like SystemModelValidate.

Examples

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Basic Examples (1)

Validate the requirement, "At no time should the control signal exceed 1.5 for more than 2 seconds.":

Use SystemModelSustain to validate a condition that has a constrained duration:

Scope (2)

Basic Uses (1)

Validate requirements in a model of a pendulum:

Validate the requirement, "The angle must never be greater than or equal to 0 for less than seconds.":

Validate the requirement, "Whenever the angle is non-negative for a duration between and seconds, the angular velocity must be non-negative.":

Extract the failure plot:

Duration (1)

Validate requirements that are duration dependent in a model of a pendulum:

Validate the requirement, "The angle must never be greater than or equal to 0 for less than seconds.":

Validate the requirement, "The angle must never be greater than or equal to 0 for more than seconds.":

Validate the requirement, "The angle must never be greater than or equal to 0 for a duration between and seconds.":

Use time quantities to specify durations:

Validate the requirement, "The angle must never be greater than or equal to 0 for less than seconds.":

Extract the failure plot:

Applications (1)

Start with a model for a continuous stirred-tank reactor:

Apply a constant inflow rate for the jacket medium and simulate for 8 hours:

Validate the requirement, "The tank temperature can only stay above 337 K for 1 hour at most.":

Show the failure plot:

The temperature is outside this validity range for about 1.2 hours:

Plot the temperature in the tank together with the bound:

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