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FDC help: output-list
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<h2>
List of output signals from the <i>Beaver</i> model
</h2>
<p>The dynamic model of the 'Beaver' aircraft determines a large list of output signals, which are all sent to the Matlab workspace by means of <i>To Workspace</i> blocks. A small subsection of those outputs is connected to <i>Outport</i> blocks in the first level of the <i><a href="beaver.htm">Beaver</a></i> model (i.e. the system <i>Beaver</i> or one of its subsystem equivalents). This first level has been shorthanded as '<i><a href="level1.htm">Level 1</a></i>' in these helpfiles.</p>
<p>The <i>Outport</i> blocks are needed to connect the model to other systems, while the outputs that are sent to the Matlab workspace are used for post-simulation analysis of the results. For practical reasons, it was decided to connect only the sixteen outputs which were needed to simulate the
'Beaver' <a href="apilot.htm">autopilot models</a> to <i>Outport</i> blocks; all other outputs are sent to the workspace only.</p>
<p>If a connecting system requires other output signals from the aircraft model, it will be necessary to add more <i>Outport</i> blocks to the first level of the aircraft model. For instance: if you want to examine new control laws that use accelerations as reference signals, these signals must be connected to new <i>Outport</i> blocks in the first level of the <i>Beaver</i> model; currently the acceleration outputs are sent to the Matlab workspace only.</p>
<p>However, please be aware that changes in the I/O definitions of <i>Level 1</i> may affect other systems that make use of the aircraft model, as well as Matlab programs that access this model. For this reason, if I/O changes are really necessary, it is probably a better idea to create an independent copy of the aircraft model first (copy from the model library, then break the library links!) and modify this copy, rather than the original.</p>
<h3>
First-level outputs
</h3>
<p>The system <i>Beaver</i> (or a subsystem-equivalent of that model) can be treated as a <i>black-box</i> model, which can be accessed through its input and output ports only. The <i>Beaver</i> model currently contains sixteen <i>Outport</i> blocks in its <a href="level1.htm">first level</a>:</p>
<pre>
V, alpha, beta, p, q, r, psi, theta, phi, xe, ye, H
Hdot
pb/2V, qc/V, rb/2V
</pre>
<p>i.e., the aircraft states, rate of climb, and the dimensionless rotational speeds,
in that particular order. These variables are needed to connect the
'Beaver' model to the <a href="apilot.htm">autopilot models</a> from the FDC toolbox. </p>
<h3>
Outputs which are sent to the Matlab workspace
</h3>
<p>During simulations, the time-trajectories of <i>all</i> 89 available output
signals are sent to the matrix <i>Out</i> in the Matlab workspace. The
columns of this matrix contain the time-trajectories of these outputs,
numbered as follows:</p>
<pre>
Out = [x' xdot' ybvel' yuvw' ydl' ypow' yacc' Caero' Cprop' ...
FMaero' FMprop' Fgrav' Fwind' yatm' yad1' yad2' yad3']'
x = [V alpha beta p q r psi theta phi xe ye H]' (1...12)
xdot = dx/dt, {<a href="vabdot.htm">Vabdot</a>, <a href=
"pqrdot.htm">pqrdot</a>, <a href="eulerdot.htm">Eulerdot</a>, <a href=
"xyhdot.htm">xyHdot</a>} (13...24)
ybvel = [u v w]' {<a href=
"uvw.htm">uvw</a>} (25...27)
yuvw = [udot vdot wdot]' {<a href=
"uvwdot.htm">uvwdot</a>} (28...30)
ydl = [pb/2V qc/V rb/2V]' {<a href=
"dimless.htm">Dimless</a>} (31...33)
yfp = [gamma fpa chi Phi]' {<a href=
"flpath.htm">Flpath</a>} (34...37)
ypow = [dpt P]' {<a href=
"power.htm">Power</a>} (38, 39)
yacc = [Ax Ay Az axk ayk azk]' {<a href=
"accel.htm">Accel</a>} (40...45)
Caero = [CXa CYa CZa Cla Cma Cna]' {<a href=
"aeromod.htm">Aeromod</a>} (46...51)
Cprop = [CXp CYp CZp Clp Cmp Cnp]' {<a href=
"engmod.htm">Engmod</a>} (52...57)
FMaero= [Xa Ya Za La Ma Na]' {<a href=
"fmdims.htm">FMdims</a>} (58...63)
FMprop= [Xp Yp Zp Lp Mp Np]' {<a href=
"fmdims.htm">FMdims</a>} (64...69)
Fgrav = [Xgr Ygr Zgr]' {<a href=
"gravity.htm">Gravity</a>} (70...72)
Fwind = [Xw Yw Zw]' {<a href=
"fwind.htm">Fwind</a>} (73...75)
yatm = [rho ps T mu g]' {<a href=
"atmosph.htm">Atmosph</a>} (76...80)
yad1 = [a M qdyn]' {<a href=
"airdata1.htm">Airdata1</a>} (81...83)
yad2 = [qc Ve Vc]' {<a href=
"airdata2.htm">Airdata2</a>} (84...86)
yad3 = [Tt Re Rc]' {<a href=
"airdata3.htm">Airdata3</a>} (87...89)
</pre>
<p>The names of the masked subsystem blocks in which these outputs are
calculated have been put between curly braces. The numbers of the
corresponding columns in the outputmatrix <i>Out</i> have been put between
round brackets. After finishing a simulation, the time-trajectories, stored
in the matrix <i>Out</i> can be plotted against the time-axis which is
stored in the vector <i>time</i>. For instance, if you want to plot the
<i>n</i><sup>th</sup> column of <i>Out</i>, the plot-command looks like:</p>
<pre>
plot(time,Out(:,n))
</pre>
<p>where 1 <= <i>n</i> <= 89. The appropriate value of <i>n</i> can be
retrieved from the list above. It is important to notice that this list
represents the default definition of <i>Out</i>, used in the system
<i>Beaver</i>. You may wish to add more outputs, or delete unwanted outputs
from this list, by adding and/or deleting blocks to/from the system. In
that case, this list needs to be updated accordingly.</p>
<h3>
Using the Matlab-macro <i>RESULTS</i>
</h3>
<p>If you want to plot simulation results by directly using the matrix
<i>Out</i>, as demonstrated above, you need to know the column numbers of
the different outputs. However, if your system uses the same definitions of
the matrices <i>In</i> (see the list of <a href=
"inputs.htm">inputsignals</a>) and <i>Out</i> as the system <i>Beaver</i>,
it is easier to run <i><a href="results.htm">RESULTS</a></i> first before
plotting the results, to get separate time-trajectories of all
input and output variables with self-explaining variable names. If you run
<i>RESULTS</i>, the following outputvariables will be created in the
Matlab workspace:</p>
<pre>
V : airspeed [m/s]
alpha : angle of attack [rad] or [deg]
beta : sideslip angle [rad] or [deg]
p : roll-rate [rad/s] or [deg/s]
q : pitch-rate [rad/s] or [deg/s]
r : yaw-rate [rad/s] or [deg/s]
psi : yaw-angle [rad] or [deg]
theta : pitch-angle [rad] or [deg]
phi : roll-angle [rad] or [deg]
xe : X-coordinate in Earth-axes [m]
ye : Y-coordinate in Earth-axes [m]
H : altitude [m]
Vdot : time-derivative of airspeed [m/s^2]
alphadot : time-derivative of alpha [rad/s] or [deg/s]
betadot : time-derivative of beta [rad/s] or [deg/s]
pdot : time-derivative of p [rad/s^2] or [deg/s^2]
qdot : time-derivative of q [rad/s^2] or [deg/s^2]
rdot : time-derivative of r [rad/s^2] or [deg/s^2]
psidot : time-derivative of psi [rad/s] or [deg/s]
thetadot : time-derivative of theta [rad/s] or [deg/s]
phidot : time-derivative of phi [rad/s] or [deg/s]
xedot : time-derivative of xe [m/s]
yedot : time-derivative of ye [m/s]
Hdot : time-derivative of H [m/s]
u : component of V along XB-axis [m/s]
v : component of V along YB-axis [m/s]
w : component of V along ZB-axis [m/s]
udot : time-derivative of u [m/s^2]
vdot : time-derivative of v [m/s^2]
wdot : time-derivative of w [m/s^2]
pb/2V : dimensionless roll-rate; b is the wingspan [m]
qc/V : dimensionless pitch-rate; c is the mean aerodynamic
chord [m]
rb/2V : dimensionless yaw-rate; where b is the wingspan [m]
gamma : flightpath angle [rad] or [deg]
fpa : flightpath acceleration [m/s^2]
chi : azimuth angle [rad] or [deg]
Phi : bank angle [rad] or [deg]
dpt : dimensionless pressure increase across propeller [-]
P : engine power [Nm/s]
Ax : specific force along XB-axis [g]
Ay : specific force along YB-axis [g]
Az : specific force along ZB-axis [g]
axk : kinematic acceleration along XB-axis [g]
ayk : kinematic acceleration along YB-axis [g]
azk : kinematic acceleration along ZB-axis [g]
CXa : coefficient of aerodynamic force along XB-axis [-]
CYa : coefficient of aerodynamic force along YB-axis [-]
CZa : coefficient of aerodynamic force along ZB-axis [-]
Cla : coefficient of aerodynamic moment around XB-axis [-]
Cma : coefficient of aerodynamic moment around YB-axis [-]
Cna : coefficient of aerodynamic moment around ZB-axis [-]
CXp : coefficient of engine force along XB-axis [-]
CYp : coefficient of engine force along YB-axis [-]
CZp : coefficient of engine force along ZB-axis [-]
Clp : coefficient of engine moment around XB-axis [-]
Cmp : coefficient of engine moment around YB-axis [-]
Cnp : coefficient of engine moment around ZB-axis [-]
Xa : aerodynamic force along XB-axis [N]
Ya : aerodynamic force along YB-axis [N]
Za : aerodynamic force along ZB-axis [N]
La : aerodynamic moment around XB-axis [Nm]
Ma : aerodynamic moment around YB-axis [Nm]
Na : aerodynamic moment around ZB-axis [Nm]
Xp : engine force along XB-axis [N]
Yp : engine force along YB-axis [N]
Zp : engine force along ZB-axis [N]
Lp : engine moment around XB-axis [Nm]
Mp : engine moment around YB-axis [Nm]
Np : engine moment around ZB-axis [Nm]
Xgr : gravity force along XB-axis [N]
Ygr : gravity force along YB-axis [N]
Zgr : gravity force along ZB-axis [N]
Xw : wind force along XB-axis [N]
Yw : wind force along YB-axis [N]
Zw : wind force along ZB-axis [N]
rho : airdensity [kg/m^3]
ps : static pressure [N/m^2]
T : temperature [K]
mu : dynamic viscosity [kg/(m*s)]
g : acceleration of gravity [m/s^2]
a : speed of sound [m/s]
M : Mach number [-]
qdyn : dynamic pressure [N/m^2]
qc : impact pressure [N/m^2]
Ve : equivelent airspeed [m/s]
Vc : calibrated airspeed [m/s]
Tt : total temperature [K]
Re : Reynolds number per unit length [1/m]
Rc : Reynolds number with respect to mean aerodyn. chord [-]
</pre>
<p>The results can now easily be plotted with commands such as:</p>
<pre>
plot(time,alpha)
</pre>
<p>where the variable <i>time</i> contains the time-axis, created during the
last simulation.</p>
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