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.
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.
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
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 |
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 |
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.
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
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 |
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 |