📄 outputs.htm
字号:
<HTML>
<HEAD>
<TITLE>FDC help: output-list</TITLE>
</HEAD>
<BODY BGCOLOR="#DED6D3" TEXT="#000000" LINK="#660033" VLINK="#660033" ALINK="#000080">
<H2>List of output signals from the system <I><FONT FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I></H2>
The system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif"><A HREF="beaver.htm">Beaver</A></FONT></I> contains the non-linear dynamic model of the DHC-2 'Beaver' aircraft, which consists of twelve state equations, forces and moment equations, airdata equations, and many additional output equations. <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I> is a graphical S<SMALL>IMULINK</SMALL> block-diagram.
<H2>S-function in/outputs vs. in/outputs sent to the M<SMALL>ATLAB</SMALL> workspace</H2>
It is important to notice that the number of outputs which are sent to the M<SMALL>ATLAB</SMALL> workspace by means of <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">To Workspace</FONT></I> blocks is considerably larger than the number of <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks, representing 'S-function outputs' of the system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>. The <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks are needed for connecting other systems to the output-side of the system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>, e.g., systems with models of sensor dynamics, controllers, etc. Unfortunately, S<SMALL>IMULINK</SMALL> does not accept vector outputs to be connected to <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks within the first level of a graphical system; therefore, only a small subset of the output variables from <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I> have actually been connected to the <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks.<BR><BR>
By default, the sixteen outputs which were needed to simulate the 'Beaver' autopilot are connected to <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks. If other output signals are needed by systems which ought to be connected to <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>, it is necessary to add more <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks to this list of 'S-function outputs'. For instance: if you want to examine control laws which use accelerations as reference signals, these signals must be connected to new <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks in the first level of <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>. Currently, the accelerations are send to the M<SMALL>ATLAB</SMALL> workspace only, but they cannot yet be used as inputs to other S<SMALL>IMULINK</SMALL> systems, connected to the output side of the system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>.<BR><BR>
Currently, it is not possible to send complete vectors through individual <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Inport</FONT></I> and <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks in the first level of a graphical system (where they serve to connect the graphical system to other S<SMALL>IMULINK</SMALL> systems, or to provide access to the system for analytical tools such as trim and linearization routines). <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Inport</FONT></I> and <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks in the first level of graphical S<SMALL>IMULINK</SMALL> systems only accept <I>scalar</I> signals, which is really a serious limitation of S<SMALL>IMULINK</SMALL>! Hopefully, this problem will be solved in future S<SMALL>IMULINK</SMALL> versions!
<H3>S-function outputs
</H3>
The system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I> can be treated as a <I>black-box</I> model, which needs to be accessed through its input and output ports only. <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I> currently contains sixteen <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Outport</FONT></I> blocks in the first level of its graphical block-diagram. These sixteen 'S-function outputs' form a subset of the 89 outputs which are sent to the M<SMALL>ATLAB</SMALL> workspace (<A HREF="#outputlist">see below</A>). By default, these sixteen outputs are:
<PRE> V, alpha, beta, p, q, r, psi, theta, phi, xe, ye, H
Hdot
pb/2V, qc/V, rb/2V
</PRE>
i.e., the states, rate of climb, and the dimensionless rotational speeds, in that particular order. These variables are needed for simulations of the 'Beaver' autopilot, including the linear state-space models of the dynamics of the control surfaces, steering column/wheel, cables, and actuators. Other sets of 'S-function outputs' can be implemented only by editing the system <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I> according to your own wishes. <BR><BR>
See the description of the first level in the block-diagram of the system Beaver (here denoted as <A HREF="level1.htm">Level 1</A>) for more information about the I/O structure of this system.
<A NAME= "outputlist"><H3>Outputs which are stored in the M<SMALL>ATLAB</SMALL> workspace</H3>
</A>
During simulations, the time-trajectories of <I>all</I> available output signals are sent to the matrix <I>Out</I> in the M<SMALL>ATLAB</SMALL> workspace. The columns of this matrix contain the time-trajectories of these outputs, numbered as follows:
<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>
The names of the masked subsystem blocks in which these outputs are calculated have been put between accolades. 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:
<PRE> plot(time,Out(:,n))
</PRE>
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><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></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 is not valid anymore.
<H3>Using the Matlab-macro <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">RESULTS</FONT></I></H3>
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><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">Beaver</FONT></I>, it is also possible to run <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif"><A HREF="results.htm">RESULTS</A></FONT></I> before plotting the results, in order to get separate time-trajectories of all input and output variables with self-explaining variable names. If you run <I><FONT SIZE=2 FACE="Arial","Helvetica","Sans Serif">RESULTS</FONT></I>, the following <I>output</I>variables will be created in the M<SMALL>ATLAB</SMALL> workspace:
<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>
The results can now be plotted with commands such as:
<PRE> plot(time,alpha)
</PRE>
where the variable <I>time</I> contains the time-axis, created during the last simulation.
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -