# nonlinearDynamics

Class: Aero.FixedWing
Namespace: Aero

Calculate dynamics of fixed-wing aircraft

Since R2021a

## Syntax

```state_derivatives = nonlinearDynamics(aircraft,state) ```

## Description

`state_derivatives = nonlinearDynamics(aircraft,state)` returns the column vector of `state_derivatives` of the fixed-wing aircraft `aircraft` from the initial state `state`.

## Input Arguments

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`Aero.FixedWing` object, specified as a scalar.

`Aero.FixedWing.State` specified as a scalar.

## Output Arguments

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State derivatives with respect to time, returned as a vector. The rate vector size depends on the degrees of freedom, and is defined in the following form:

```4th order point mass: DYDT(1) = dXN/dt DYDT(2) = dXD/dt DYDT(3) = dU/dt DYDT(4) = dW/dt 6th order point mass: DYDT(1) = dXN/dt DYDT(2) = dXE/dt DYDT(3) = dXD/dt DYDT(4) = dU/dt DYDT(5) = dV/dt DYDT(6) = dW/dt 3 DOF: DYDT(1) = dXN/dt DYDT(2) = dXD/dt DYDT(3) = dU/dt DYDT(4) = dW/dt DYDT(5) = dQ/dt DYDT(6) = dTheta/dt 6 DOF: DYDT(1) = dXN/dt DYDT(2) = dXE/dt DYDT(3) = dXD/dt DYDT(4) = dU/dt DYDT(5) = dV/dt DYDT(6) = dW/dt DYDT(7) = dP/dt DYDT(8) = dQ/dt DYDT(9) = dR/dt DYDT(10) = dPhi/dt DYDT(11) = dTheta/dt DYDT(12) = dPsi/dt```

## Examples

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Calculate the dynamics of Cessna 182.

```[C182, CruiseState] = astC182(); dydt = nonlinearDynamics(C182, CruiseState)```
```dydt = 220.1000 0 0 -2.8323 0 -0.0040 0 1.3922 0 0 0 0```

## Limitations

When used with `Simulink.LookupTable` objects, this method requires a Simulink® license.

## Version History

Introduced in R2021a