sdo.requirements.SmoothnessConstraint

Impose bounds on gradient magnitude of variable

Description

Use the sdo.requirements.SmoothnessConstraint object to impose an upper bound on the gradient magnitude of a variable in a Simulink^® model. The variable can be a vector, matrix, or multidimensional array that is a parameter in your model, such as the data of a lookup table. For example, consider a car engine controller whose gain changes under different operating conditions determined by the car speed. You can use a gradient bound constraint to limit the rate at which the controller gain changes per unit change in vehicle speed.

You can use the requirement object as an input to your cost function and then use the evalRequirement command to evaluate whether your test data satisfies the requirement. If the test data is not smooth, the gradient of the test data is greater than the required bound. You can then use the cost function and sdo.optimize to perform response optimization, subject to satisfaction of the specified requirement. If you are performing sensitivity analysis, after you generate parameter samples, you can use the cost function and sdo.evaluate to evaluate the requirement for each generated sample.

Creation

Syntax

smooth_req = sdo.requirements.SmoothnessConstraint

smooth_req = sdo.requirements.SmoothnessConstraint(PropertyName=Value)

Description

smooth_req = sdo.requirements.SmoothnessConstraint creates an sdo.requirements.SmoothnessConstraint requirement object and assigns default values to its properties. Use dot notation to customize the properties. Use the evalRequirement command to evaluate whether test data satisfies the specified requirement.

smooth_req = sdo.requirements.SmoothnessConstraint(PropertyName=Value) specifies one or more properties using name-value arguments. For example, smooth_req = sdo.requirements.SmoothnessConstraint(GradientBound=2.5) creates an sdo.requirements.SmoothnessConstraint object and specifies the gradient magnitude bound as 2.5.

Output Arguments

smooth_req — Gradient magnitude bound

sdo.requirements.SmoothnessConstraint object

Gradient magnitude bound, returned as an sdo.requirements.SmoothnessConstraint object.

Properties

Description — Requirement description

'' (default) | character vector

Requirement description, specified as a character vector.

Example: 'Requirement 1 for myModel.'

Data Types: char

GradientBound — Gradient magnitude bound

1 (default) | nonnegative finite real scalar

Gradient magnitude bound, specified as a nonnegative finite real scalar. When you use the evalRequirement command to evaluate test data, the software checks whether the gradient magnitude of the test data is less than or equal to the specified bound. If the gradient of the test data is greater than the required bound, the test data is not smooth.

Data Types: double

Name — Name of requirement

'' (default) | character vector

Name of requirement, specified as a character vector.

Example: 'Requirement1'

Data Types: char

Type — Gradient magnitude bound type

'<=' (default)

Gradient magnitude bound type, specified as lower bound, '<='. When you use the evalRequirement command, the software checks whether the gradient magnitude of the test data is less than or equal to the specified in GradientBound property.

Data Types: char

Object Functions

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

Examples

Specify a Bound on the Gradient Magnitude of a Variable

Create a requirement object to impose a bound on the gradient magnitude of a variable. The object has default properties.

Requirement = sdo.requirements.SmoothnessConstraint;

Specify the gradient magnitude bound value.

Requirement.GradientBound = 5;

Alternatively, specify the bound during object creation.

Requirement = sdo.requirements.SmoothnessConstraint('GradientBound',5);

You can now use the evalRequirement command to evaluate whether test data satisfies the requirement.

Version History

Introduced in R2016b