computeLongitudinalFlyingQualities

Calculate short-period and long-period (phugoid) mode characteristics of specified state-space model

Description

example

computeLongitudinalFlyingQualities(modelToAnalyze) calculates longitudinal flying qualities (short-period and phugoid mode) using the linear system state-space model selected in the input dialog window and compares the results against MIL-F-8785C requirements.

computeLongitudinalFlyingQualities(modelToAnalyze,linSys) calculates longitudinal flying qualities (short-period and phugoid mode) using the linear system state-space model selected in the input dialog window. The state-space model must have at least these four states:

  • U

  • w

  • q

  • theta

or all eight of these states:

  • U

  • w

  • q

  • theta

  • v

  • p

  • r

  • phi

To create a usable state-space model, use the linearizeAirframe function.

computeLongitudinalFlyingQualities(modelToAnalyze,linSys,generatePlots) calculates longitudinal flying qualities (short-period and phugoid mode) using linear system state-space model linSys.

Examples

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Calculate longitudinal flying qualities of linSys, a state space model DehavillandBeaverAnalysisModel This example starts the flight control analysis template using asbFlightControlAnalysis and trims the model around the opSpecDefault operating point specification object. It then linearizes the airframe model around the opTrim operating point and calculates the short- and long-period (phugoid) mode characteristics of linSys.

asbFlightControlAnalysis('3DOF', 'SkyHoggAnalysisModel');
opSpecDefault = SkyHogg3DOFOpSpec('SkyHoggAnalysisModel');
opTrim = trimAirframe('SkyHoggAnalysisModel', opSpecDefault);
linSys = linearizeAirframe('SkyHoggAnalysisModel', opTrim)
flyingQual = computeLongitudinalFlyingQualities('SkyHoggAnalysisModel', linSys)

Compare against MIL-F_8785C requirements.

Calculate longitudinal flying qualities for the model DehavillandBeaverAnalysisModel and specify a state-space, linSys.

asbFlightControlAnalysis('6DOF', 'DehavillandBeaverAnalysisModel');
opSpecDefault = DehavillandBeaver6DOFOpSpec('DehavillandBeaverAnalysisModel');
opTrim = trimAirframe('DehavillandBeaverAnalysisModel', opSpecDefault);
linSys = linearizeAirframe('DehavillandBeaverAnalysisModel', opTrim);
lonFlyingQual = computeLongitudinalFlyingQualities('DehavillandBeaverAnalysisModel', linSys);
latFlyingQual = computeLateralDirectionalFlyingQualities('DehavillandBeaverAnalysisModel', linSys);

Get the list of longitudinal flying qualities for the model.

lonFlyingQual
lonFlyingQual = 

  struct with fields:

        PhugoidMode: [1×1 struct]
    ShortPeriodMode: [1×1 struct]

Get the phugoid flying quality.

lonFlyingQual.PhugoidMode
ans = 

  struct with fields:

                    root: [2×1 double]
         oscillatoryMode: 'Phugoid (Long-Period Mode)'
    MILF8785CRequirement: 'Satisfies MIL-F-8785C Level 1 Criteria (zeta_ph >= 0.04)'
            DampingRatio: 0.0926
             NaturalFreq: 0.1540
         TimeToDoubleAmp: -48.5747
            TimeConstant: []
                response: 'converging oscillatory motion'
             description: 'complex conjugate pair with negative real components'

Get the results of the comparison with the MIL-F-8785C requirements.

lonFlyingQual.PhugoidMode.MILF8785CRequirement
ans =

    'Satisfies MIL-F-8785C Level 1 Criteria (zeta_ph >= 0.04)'

Input Arguments

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Model on which to perform flight control analysis using the linear state-space model linSys.

Data Types: char | string

Linear state-space model object used to perform flight control analysis on modelToAnalyze.

Data Types: char | string

Display pole-zero map for the linear system state-space model.

Data Types: char | string

Introduced in R2018b