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sdo.requirements.OpenLoopGainPhase

Nichols response bound

Description

Specify piecewise-linear bounds on the Nichols (gain-phase) response of a linear system. You can then optimize the model response to meet these bounds using sdo.optimize.

You can specify an upper or lower bound, include multiple linear edges, and extend the bounds to + or –inf.

You must have Simulink® Control Design™ software to specify open-loop gain and phase requirements.

Properties

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Gain values for a piecewise linear bound, specified as a vector indicating the start and end values in decibels for all the edges in the piecewise-linear bound. The property must be a nx2 array of finite doubles, where each row specifies the start and end gain values of an edge. The number of rows must match the number of rows of the BoundPhases property.

Use set to set this and the BoundPhases properties simultaneously.

Phase values for a piecewise-linear bound, specified as a vector indicating the start and end values in degrees for all the edges in the piecewise-linear bound. The property must be a nx2 array of finite doubles, where each row specifies the start and end phase values of an edge. The number of rows must match the number of rows of the BoundGains property.

Use set to set this and the BoundGains properties simultaneously.

Requirement description, specified as a character vector. For example, 'Requirement on signal 1'.

Magnitude units of the requirement, specified as either 'db' (decibels) or 'abs' (absolute units).

Requirement name, specified as a character vector.

Extend bound in a negative or positive time direction, specified as a vector. Use to bound signals that extend beyond the coordinates specified by the BoundPhases and BoundGains properties.

Must be a 1x2 logical array. If true, the first or last edge of the bound is extended to infinity.

Phase units of the requirement specified as one of the following values:

  • 'deg' (degrees)

  • 'rad' (radians)

Gain and phase requirement type, specified as one of the following:

  • '>=' — Lower bound

  • '<=' — Upper bound

Usage

Description

olgainphase_req = sdo.requirements.OpenLoopGainPhase creates a sdo.requirements.OpenLoopGainPhase object and assigns default values to its properties.

example

gainphase_req = sdo.requirements.OpenLoopGainPhase(Name,Value) specifies one or more properties using name-value arguments. Name is a property name and Value is the corresponding value. Name must appear inside quotes. You can specify several name-value arguments in any order as Name1,Value1,...,NameN,ValueN.

Object Functions

evalRequirementEvaluate design requirement
copyCopy design requirement
getGet design requirement property values
setSet design requirement property values

Examples

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Construct an open-loop gain and phase object, and specify gain and phase requirements.

r = sdo.requirements.OpenLoopGainPhase;
set(r,'BoundPhases',[-120 -120; -120 -150; -150 -180],...
      'BoundGains',[20 0; 0 -20; -20 -20]);

Alternatively, you can specify the gain and phase requirements during construction.

r = sdo.requirements.OpenLoopGainPhase('BoundPhases',...
		[-120 -120; -120 -150; -150 -180],'BoundGains',...
		[20 0; 0 -20; -20 -20]);

Alternatives

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

Version History

Introduced in R2010b