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The FDC toolbox
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FDC 1.3 is a Matlab/Simulink toolbox for Flight Dynamics and
Control analysis, which has been applied to the De Havilland DHC-2
'Beaver' aircraft. The FDC package includes a full-featured
nonlinear dynamic model of the 'Beaver', implemented in a modular
Simulink blockdiagram structure. It also contains some Matlab pro-
grams, which access this Simulink system for the determination of
steady-state trimmed flight conditions and linearization of the
aircraft model.
    FDC 1.3 also contains additional Simulink systems which can
be coupled to the input or output side of the nonlinear aircraft
model. These systems include wind and turbulence generators for
assessing aircraft responses to wind and/or atmospheric turbulence,
and radio navigation signal generators, to simulate ILS or VOR
radio-navigation applications (for instance: autopilot modes).

Although the FDC toolbox has been built around a model of the
DHC-2 'Beaver' aircraft, it can easily be adapted for analyzing
ANY kind of aircraft within the same graphical user environment,
based upon Simulink and Matlab.

The heart of the FDC package is formed by the system BEAVER,
which has been contained in the subdirectory AIRCRAFT. This sys-
tem contains the nonlinear state equations which determine the
motions of the aircraft, as well as a large number of additional
output equations. Input and output ports make it possible to
connect this system to other Simulink systems, such as control
laws of autopilot modes, input generators, sensor models, etc.
The system BEAVER can be opened by typing beaver at the Matlab
command line.
    The subdirectory AIRCRAFT also contains the blocklibrary
FDCLIB with the sublibraries FDCLIB1 to FDCLIB8. These libra-
ries together contain all blocks from the system BEAVER. Help
texts which briefly explain the function of all blocks have
been included in the subdirectory HELP.

Examples of the practical use of the system BEAVER for nonlinear,
off-line, open-loop simulations can be found in the subdirectory
EXAMPLES. The system OLOOP1 can be used to simulate open-loop
responses to control inputs. OLOOP1T is a 'tutorial system' which
gives a detailed explanation about the meaning of each block in
OLOOP1. OLOOP2 gives an example of open-loop simulations of the
'Beaver' encountering atmospheric turbulence; OLOOP2T is the
accompagnying 'tutorial'. OLOOP3 is used for creating open-loop
responses of a linearized aircraft model; OLOOP3T is the accom-
pagnying 'tutorial'.
    It is recommended to closesly examine the examples from this
subdirectory, because they demonstrate how the system BEAVER can
be used in practice. Once you know the basics, it is quite easy to
build your own open or closed-loop simulation systems of the
'Beaver' aircraft. Next, you only have to zoom in to the system
BEAVER, to find out how the aircraft equations of motion them-
selves are structured, and eventually, to adapt the structure of
this model for your own purposes.

The subdirectory APILOT contains a very detailed example of a
closed-loop simulation model, which again uses the system BEAVER
as most important element. The autopilot simulation systems
APILOT1, APILOT2, etc., may look quite complicated if you look
at them for the first time. It is certainly not recommended to
examine these systems if you don't know the basics about the
aircraft model BEAVER and the example systems OLOOP1, OLOOP2,
etc. yet, because the autopilot logic is quite complicated.
Still, the autopilot simulation systems gives you an idea about
the power of the Simulink simulation structure, used in the FDC
package.

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The FDC toolbox, Copyright Marc Rauw 1994-1998.