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      FDC help: Input-list
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    <h2>
      List of input signals to the system <i>Beaver</i>
    </h2>
    <p>The <i><a href="beaver.htm">Beaver</a></i> model contains the nonlinear
    dynamic model of the DHC-2 &#39;Beaver&#39; aircraft, which consists of
    twelve state equations, forces and moment equations, airdata equations, and
    many additional output equations, implemented as graphical Simulink
    block-diagram.</p>
    <p>There are two versions of this model: the system <i>Beaver</i>, which is used to access the aircraft model from the Matlab workspace, and a 'subsystem equivalent' of this system, which is used to call the aircraft model from other systems, such as the <a href="oloop.htm">open-loop simulation models</a> or the <a href="apilot.htm">autopilot models</a>. For simulation purposes, aircraft linearization and the determination of
    steady-state trimmed flight conditions, the system <i>Beaver</i> or one of its subsystem equivalents can be  treated as a 'black-box', which can be accessed through the input and output ports only.</p> 
    <h3>
      Inputs to the system <i>Beaver</i>
    </h3>
    <p>The system <i>Beaver</i>, contains twelve (scalar) <i>Inport</i> blocks, which means that the system must be accessed with an input vector of length twelve. This input vector (i.e. <i>the</i> inputvector to the system <i>Beaver</i>) has been defined as: </p>
<pre>
  u     = [uaero&#39;  uprop&#39;  uwind&#39;]&#39;

  uaero = [deltae deltaa deltar deltaf]&#39;
  uprop = [n pz]&#39;
  uwind = [uw vw ww uwdot vwdot wwdot]&#39;


  deltae: elevator deflection [rad]
  deltaa: ailerons deflection [rad]
  deltar: rudder deflection [rad]
  delfaf: flap deflection [rad]

  n     : engine speed [RPM]
  pz    : manifold pressure [&quot;Hg]

  uw    : wind &amp; turbulence velocity along XB-axis [m/s]
  vw    : wind &amp; turbulence velocity along YB-axis [m/s]
  ww    : wind &amp; turbulence velocity along ZB-axis [m/s]
  uwdot : d(uw)/dt [m/s^2]
  vwdot : d(vw)/dt [m/s^2]
  wwdot : d(ww)/dt [m/s^2]
</pre>
    <p>The subsystem equivalents of the model have three input ports only, which correspond with the vectors <i>uaero</i>, <i>uprop</i>, and <i>uwind</i>, as defined above.</p>
    <p>The input-variables from the input-vector <i>u</i> are used by the blocks
    <i><a href="aeromod.htm">Aeromod</a></i>, <i><a href=
    "engmod.htm">Engmod</a></i>, and <i><a href="fwind.htm">Fwind</a></i>. See the list of <a href=
    "outputs.htm">outputs</a> for an exact definition of the outputvector from
    the <i><a href="beaver.htm">Beaver</a></i> model. See also the description of the first level of this model (denoted as <i><a href="level1.htm">Level 1</a></i>) to find
    out how the definition of the inputvector <i>u</i> is related to the
    graphical block-diagram structure in this system level.</p>
     <p><b>Note:</b> if you want to adapt this model to implement the dynamics of another aircraft, it may well be possible
    that you need other input-variables than the twelve listed above. In that
    case, the first level of the aircraft model needs to be changed accordingingly, and the file <small>RESULTS.M</small> needs to be edited. As the first level of the system <i>Beaver</i> and its subsystem equivalents functions as an interface between the aircraft model and 'the outside world', it will also be necessary to edit any Matlab program or Simulink system that accesses the aircraft model through this first level if the I/O definitions are changed. </p>
    <h3>
      Collecting the input signals in the Matlab workspace
    </h3>
    <p>During simulations, the time-trajectories of these input variables are
    recorded in the matrix <i>In</i> in the Matlab workspace. The matrix
    <i>In</i> contains twelve columns and <i>N</i> rows, where <i>N</i> is the
    number of time-steps taken during the simulation. The twelve columns
    correspond with the twelve elements of the inputvector <i>u</i>, given above, so: </p>
<pre>
  In == [  u&#39;(t0)  ;  u&#39;(t1)  ;  u&#39;(t2)  ;  ...  ;  u&#39;(tN)  ]
</pre>
    <p>The twelve columns of <i>In</i> therefore correspond with the variables
    <i>deltae</i>, <i>deltaa</i>, <i>deltar</i>, <i>deltaf</i>, <i>n</i>,
    <i>pz</i>, <i>uw</i>, <i>vw</i>, <i>ww</i>, <i>uwdot</i>, <i>vwdot</i>, and
    <i>wwdot</i> (in this particular order), respectively. The output trajectories are sent to the matrix <i>Out</i>, and a time-axis is
    send to the vector <i>time</i>. See the <a href="outputs.htm">list of
    outputs</a> for more information. </p>
    <h3>
      Using the Matlab-macro <i>RESULTS</i>
    </h3>
    <p>Although the time-trajectories of the input variables are thus send to the
    matrix <i>In</i> in the Matlab workspace, analyzing these results may still
    be difficult, because one needs to know the definition of
    this matrix in order to make sense of it. To help with the interpretation of the simulation results, the Matlab program <i><a href=
    "results.htm">RESULTS</a></i> was created.</p>
     <p>If you run <i>RESULTS</i> after a simulation, the time-trajectories of
    <i>deltae</i>, <i>deltaa</i>, <i>deltar</i>, <i>deltaf</i>, <i>n</i>,
    <i>pz</i>, <i>uw</i>, <i>vw</i>, <i>ww</i>, <i>uwdot</i>, <i>vwdot</i>, and
    <i>wwdot</i> will be extracted from the matrix <i>In</i> as separate
    <i>vectors</i>. These vectors can be plotted against the vector
    <i>time</i>, which was created together with the matrices <i>In</i> and
    <i>Out</i>. The resulting plot commands look like: </p>
<pre>
        plot(time,uwdot)
        plot(time,deltae)

        etc.
</pre>

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