曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
Equations
For a detailed discussion of the equations from the blocks GSnoise1 and GSnoise2, refer
to section 5.1.2.
• Glideslope noise, [μA]:
Di
gs(s) = Hgs(s) w4(s)
where Di
gs is the glideslope noise, w4 is a white noise signal, generated internally
within the block GSnoise1 or GSnoise2, and Hgs is the transfer function of the glideslope
noise filter.
• Transfer function of the glideslope noise filter according to AGARD R-632, used for
GSnoise1:
Hgs(s) = sgs
r
2Lgs
V
1
1 + Lgs
V s
Note: the value of the airspeed V used by GSnoise1 is assumed to remain constant
during the simulations. This is not entirely accurate, but if this value is set equal to the
(final) approach speed of the aircraft, the results are quite usable, keeping in mind that
this equation only provides an approximation of actual glideslope noise anyhow. Lgs
is the scale-length of the glideslope noise; sgs is the standard-deviation.
• Transfer function of the glideslope noise filter according to NASA CR-2022, used for
GSnoise2:
Hgs(s) = 3.9875
0.25 + s
Inputs
None.
Outputs
Di
gs glideslope noise, D_igs*
Parameters
For the AGARD R-632 version (GSnoise1), the user must specify the scale length Lgs, the
standard deviation sgs, and the approach speed of the aircraft. The parameters can be set
in the mask dialog, which is opened after double-clicking GSnoise1. The NASA CR-2022
version (GSnoise2) doesn’t require any parameters to be entered.
Connections
in: no connections.
out: Di
gs is meant to be added to the original glideslope current igs. If steady-state errors
are also taken into account, this summation must take place after sending the glideslope
current through the block GSerr first. The resulting signal can e.g. be used as
an input signal for an automatic approach controller.
Type browse gsnoise at the command-line for on-line help.
10.1. The radio-navigation blocklibrary 183
ILS Main FDC library / ILS/VOR radio-nav / ILS signals / ILS
Radio-navigation library / ILS signals / ILS
Type
Masked subsystem block.
Description
The block ILS determines the nominal ILS signals for a given position of the aircraft. The
block also computes some closely associated properties, which provide more information
about the current position of the aircraft with respect to the runway and the glideslope
and localizer reference planes. The validity of the glideslope and localizer signals is verified
by an internal masked subsystem block, called ILStest.
Equations
For a detailed discussion of the equations from the block ILS, refer to section 5.1.1.
• Glideslope and localizer deviations, expressed in terms of electrical currents through
the ILS indicators in the cockpit, [μA]:
igs = Sgs #gs
iloc = Sloc Gloc
• Glideslope and localizer deviation angles, [rad]:
#gs = ggs + arctan
Hf
Rgs
Gloc = arcsin
dloc
Rloc
• Coordinates of the aircraft in the horizontal plane of the runway-fixed reference frame,
[m]:
xf = (xe − xRW) cos yRW + (ye − yRW) sin yRW
yf = −(xe − xRW) sin yRW + (ye − yRW) cos yRW
• Height of the aircraft above aerodrome level, [m]:
Hf = H − HRW
• Distance from the aircraft to the glidepath, measured perpendicular to the nominal
glidepath, [m]:
dgs = (Rgs tan ggs + Hf ) cos ggs
• Ground-distances from the aircraft to the glideslope and localizer transmitters, [m]:
Rgs =
q
(xgs − xf )2 + (yf − ygs)2
Rloc =
q
yf
2 + (xloc − xf )2
• Two flags, which show whether the position of the airplane allows accurate reception
of the glideslope and localizer signals, are determined with logical Boolean expressions,
derived from the glideslope and localizer coverage diagrams from figures 5.5 and 5.3 in
chapter 5. These flags are called GS_flag and LOC_flag, respectively; they are set equal
to 1 if the signals are reliable, and 0 if they are not. These flags are computed in the
internal masked subsystem block ILStest; type browse ilstest at the command-line
for more information about this block.
Inputs
uils = [ xe ye H ]T aircraft coordinates and altitude, uils
184 Chapter 10. Radio-navigation block reference
Outputs
yils1 = [ igs iloc ]T nominal currents through ILS indicators, yils1
yils2 = [ #gs Gloc ]T angles between nominal and current ILS planes, yils2
yils3 = [ xf yf Hf dgs Rgs Rloc ]T distances defining the aircraft’s approach position, yils3
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
FDC 1.4 – A SIMULINK Toolbox for Flight Dynamics and Contro(88)
