# Table of contents for on-line FDC help

This page provides links to all on-line help texts currently available for the FDC toolbox. A small introduction to the toolbox can be found here; see the FDC user manual for more information.

Click here for more information about:
Non-linear aircraft model | Radio-navigation models | Wind and turbulence models | Open-loop simulation models of the 'Beaver'
FDC Simulink libraries | Matlab utilities | Autopilot models | Matlab utilities for the autopilot models

### FDC Simulink libraries

The FDC toolbox contains several blocklibraries, which can all be reached via the main library FDCLIB:

Main FDC library | FDCLIB
Radio navigation library | NAVLIB
Wind and turbulence library | WINDLIB

Note: the blocks from the aircraft model are stored in sublibraries FDCLIB1 to FDCLIB6 and FDCLIB10; these sublibraries can all be reached via the main library FDCLIB.

### Non-linear aircraft model

The FDC toolbox is built around a modular non-linear aircraft model, which consists of many generic and a couple of aircraft-dependent subsystems and blocks.

The aircraft-dependent parts of this model were designed for the De Havilland 'Beaver' aircraft, but it shouldn't be too difficult to adapt the model for other types of aircraft. This model is stored in the Simulink system Beaver (also available as subsystem-equivalent), which contains the following subsystems (the table reflects the ordering within the Beaver model, showing the full 'path' of each subsystem):

       First level of BEAVER (Level 1)

             Beaver dynamics and output equations (Level 2)

                Airdata Group
                      Atmosph
                      Airdata1
                      Airdata2
                      Airdata3

                Aerodynamics Group
                      Dimless
                      Aeromod
                      FMdims

                Engine Group
                      Power
                      Engmod
                      FMdims

                Gravity
                Fwind
                FMsort

                Aircraft Equations of motion

                      12 ODEs
                            Vabdot
                            pqrdot
                            Eulerdot
                            xyHdot

                      xdotcorr
                      xfix
                      uvw

                Additional outputs
                      Flpath
                      uvwdot
                      Accel

                Hlpfcn

### Radio-navigation models

The library NAVLIB contains the following radio-navigation blocks:

Nominal ILS signals | ILS
Localizer noise | LOCnoise
Glideslope noise | GSnoise
Steady-state errors in localizer signal | LOCerr
Steady-state errors in glideslope signal | GSerr
Nominal VOR signals | VOR
Steady-state errors in VOR signal | VORerr

Examples which show how these blocks are to be combined for practical purposes are:

Complete ILS simulation | ILS example
Complete VOR simulation | VOR example

### Wind and turbulence models

The library WINDLIB contains the following wind and atmospheric turbulence blocks (the latter ones implemented according to the Dryden turbulence models):

Wind profile in Earth's boundary layer | BLwind
Constant horizontal wind | Cwind
Longitudinal Dryden filter with constant coefficients | UDRYD1
Lateral Dryden filter with constant coefficients | VDRYD1
Vertical Dryden filter with constant coefficients | WDRYD1
Longitudinal Dryden filter with airspeed-dependent coefficients | UDRYD2
Lateral Dryden filter with airspeed-dependent coefficients | VDRYD2
Vertical Dryden filter with airspeed-dependent coefficients | WDRYD2

Examples which show how to combine the turbulence blocks for practical purposes are:

Atmospheric turbulence filters with constant coefficients | Turb1
Atmospheric turbulence filters with airspeed-dependent coefficients | Turb2

### Open-loop simulation models of the 'Beaver' aircraft

There are three different open-loop simulation models for the 'Beaver' aircraft (which can be applied to any aircraft model that uses the same inputs and outputs as the system Beaver):

Non-linear open-loop responses to control inputs | OLOOP1
Non-linear open-loop responses to atmospheric turbulence | OLOOP2
Open-loop responses to control inputs, using a linearized aircraft model | OLOOP3

Another example of an open-loop application is the routine TRIMDEMO. There is no on-line help available for this routine yet; type `help trimdemo` at the Matlab command-line for information about that routine.

### Simulation models of the 'Beaver' autopilot

The FDC toolbox also contains a complete non-linear model of the 'Beaver' autopilot, which includes options like gain-scheduling and longitudinal/lateral cross-coupling. Two simplified versions of the autopilot simulation model were included as well in order to speed-up computations:

Autopilot simulation without sensor models, radio-navigation signals, and noise signals | APILOT1
Autopilot simulation models without noise signals | APILOT2
Complete autopilot simulation model | APILOT3

The systems PAH, RAH, and PAHRAH provide alternative implementations of the Pitch and Roll Attitude Hold modes.

The complete autopilot model APILOT3 contains the following subsystems (the list reflects the ordering in the block-diagram):

          APILOT1/2/3
                Wind and turbulence
                      Turb1
                      BLwind

                Beaver dynamics
                      Beaver

                Sensors / subtract initial conditions
                VOR (see VOR example)
                ILS (see ILS example)
                Reference signals
                Mode controller
                Asymmetrical autopilot modes
                Symmetrical autopilot modes
                Computational delay and limiters
                Actuator and cable dynamics
                Add initial inputs

### Matlab utilities for the FDC toolbox

In addition to the Simulink systems, the FDC toolbox contains a number of analytical Matlab functions and support utilities (a short overview of these functions is available here):

Aircraft model linearization utility | ACLIN
Aircraft trim utility | ACTRIM
Utility to artificially fix state variables of the non-linear aircraft model | FIXSTATE
Utility to load aircraft model parameters and other *.DAT datafiles | DATLOAD
Utility for loading *.LIN datafiles (used to store linearized models) | LINLOAD
Utility for loading *.MAT datafiles | MATLOAD
Utility for loading *.TRI datafiles (used to store trimmed flightconditions) | TRILOAD
Generic data-load function | FDCLOAD
Macro for creating datafile with aircraft model parameters | MODBUILD
FDC data-directory selection | DATADIR
FDC help-directory selection | HELPDIR
FDC directory selection function | FDCDIR
Utility to display HTML helpfiles | BROWSE
Message box utility | NEWMSGBOX
Numerical to string conversion utility | NUM2STR2
Utility for post-processing simulation results | RESULTS
Utility for plotting simulation results | RESPLOT
Utility to determine screen dimensions | SCREENSIZE
Utility to determine properties of linearized systems | SYSTPROP
Function to display a menu of options in the command-window | TXTMENU

### Matlab utilities for the autopilot models

The following two Matlab programs are necessary for the initialization of the autopilot models:

Utility to initialize the autopilot models APILOT1, APILOT2, and APILOT3 (including all subcomponents) | APINIT
Utility to define the autopilot modes for APILOT1, APILOT2, and APILOT3 | APMODE
Utility to initialize the autopilot models PAH, RAH, and PAHRAH | PRAHINIT