Small history of the FDC toolbox up till version 1.3
====================================================
The origin of this package lies in 1992, when Simulink tools were
developed for the design and analysis of a digital autopilot for the
DHC-2 'Beaver' aircraft of Delft University of Technology (Faculty
of Aerospace Engineering, Section Stability and Control). In
september 1993, a version of this Simulink 'Toolbox' was released as
a part of the MSc-thesis of the author (ref.[2]). Although this toolbox
was at that time still nameless, it will be referred to as FDC 1.0 in
this README-textfile.

In 1994, an improved version of this toolbox was developed. This
version (1.1) contained some significant improvements with regard to
the model structure and user-friendlyness of the tools. Although a
'beta-test version' was distributed in the Disciplinary Group for
Stability and Control, it was never released officially since the
report which described the new version was delayed several times.
This beta-version was called 'BEAST 1.1 beta', where BEAST was used
as an acronym for 'Beaver Simulation Toolbox'.

Since version 1.2 this package has been renamed FDC-toolbox, which
emphasizes the shift from a package that was mainly used for the design
and analysis of the 'Beaver' autopilot to a far more general toolbox for
Flight Dynamics analysis and Flight Control System design (FDC stands for
'Flight Dynamics and Control'). The old name was actually too limited to
fully account for the contents of the package. Versions 1.0 and 1.1 were
designed for Matlab 3.5 / Simulink 1.2, FDC 1.2 was designed for
Matlab 4.0 / Simulink 1.2c and Matlab 4.2 / Simulink 1.3.

Version 1.3 has been designed for Matlab 4.2 / Simulink 1.3 only. It also
requires a World Wide Web browser to view the new on-line help texts.
Two 'Service Releases' (SR1 and SR2) were created to solve some problems.
In particular, the support for non-Windows platforms has been improved.


Version 1.0
-----------
The first usable version of FDC that was actually presented in public. At
the time of publishing it was still nameless. See ref.[2] for a full
description of this toolbox.


Version 1.1 (beta)
------------------
This version was called BEAST 1.1 (beta), which meant 'Beaver Simulation
Toolbox' version 1.1. It was never 'officially' released. Compared to
version 1.0 it contained the following new and/ofimproved features:

*  Better on-line help texts for the graphical Simulink systems. These texts
   now contained complete lists of variables and units of measurements. The
   number of help texts was increased considerably. Moreover, the file-exten-
   sion for these help texts was changed from .M to .HLP.

*  Double-clicking title-blocks in graphical Simulink systems now listed
   the accompagnying help-texts in the Matlab command-window.

*  New file-extensions were introduced: .DAT (parameter files),
   .HLP (helpfiles), .LIN (linearized models), and .TRI (trimmed-flight
   conditions). This clarified the file-structure of the toolbox.

*  The user-interface of ACTRIM and ACLIN was considerably improved.

*  The trim-routine was enhanced with the option to specify the
   manifold pressure in stead of the flight path angle.

*  The old model library ACLIB was replaced by the new model library
   BEASTLIB and enhanced with many explanatory systems. All examples were
   now accessible through the main library.

*  New versions of the open-loop example systems from version 1.0 were
   created, plus 'tutorial' systems which gave a step-by-step explanation
   about the meaning of all blocks from these examples.

*  The 'button'-blocks were changed in order to show which M-file they
   would start when being double-clicked.

*  The structure of the aircraft model BEAVER was improved by adding a
   new subsystem 'Additional Outputs' to group the output blocks which
   could not logically be placed elsewhere, and by putting the help sines
   and cosines in a feedback-loop to make them available for ALL other
   blocks within the system. Also, the subsystem 'Aircraft Equations
   of Motion' was restructured in a more logical way. Feedback-loops in
   the system BEAVER were highlighted by a magenta color.

*  Some signal names which could have led to confusion in version 1.0
   were changed (e.g. FMa in stead of Fa, to denote Forces AND Moments).

*  Some bugs in the blocks ACCEL, FLPATH, and XDOTCORR of the old version
   of the system BEAVER were fixed in BEAST 1.1 (bugs reported by Zainal
   Abidin, Delft University of Technology).


Version 1.2
-----------
This version was renamed to FDC 1.2. It has been described in ref.[1].
It contained the following new features:

*  FDC 1.2 was designed for Matlab 4.0 / Simulink 1.2c (or newer) in stead
   of Matlab 3.5k / Simulink 1.2.

*  The masked blocks did not use 'hidden' parameters, read from global
   variables in the workspace, contrary to the previous versions.

*  The help texts were improved once again. Toolbox-help in 'Matlab 4.0'-
   style (contents.m files) and new help-files for the autopilot simulation
   models were included.

*  The autopilot simulation models were improved in order to make them
   better accessible by the users. The autopilot-parameter definition
   routines were made more user-friendly than before and the on-line help
   texts for these models were improved.

*  Three new examples of control-law simulations were added. These systems
   (PAH.M, RAH.M, and PAHRAH.M) represented an interim step between linear
   autopilot design and the full-featured non-linear autopilot models from
   the systems APILOT1 to APILOT3. The routine PRAHINIT.M was included to
   help definining the parameters for these example systems.

*  The Mode-controller blocks from the autopilot simulation models was
   renewed completely, together with the Matlab functions GSSWITCH.M,
   NAVSWTCH.M, and LOCSWTCH.M, which are called by S-function blocks in the
   Mode Controller subsystem. Some of the mode-definition vectors were
   re-defined in the new mode-controller and the old initialization routine
   APSTART.M was replaced by APMODE.M.

*  A user-menu APMENU.M was included in order to help the user in selecting
   the appropriate autopilot model.

*  New Matlab macros RESULTS.M and RESPLOT.M were included to facilitate the
   post-processing of simulation results.

*  The screen-formatting of the routines ACLIN and ACTRIM was improved by
   applying a slightly changed version of the Matlab function NUM2STR, called
   NUM2STR2.

*  Complete lists of variables were added to the source codes of ACLIN and
   ACTRIM. The source-codes themselves were better documented.

*  Several blocks from the library FDCTOOLS (previously called TOOLS)
   were improved. This library was equipped with a user-friendly n-switch
   generator which automatically created graphical switch-blocks with n
   inputs, where n could be specified by the user during the block-generation
   process.

*  Several minor and some major bugs in the Matlab programs from the FDC
   toolbox were fixed. The package was made more 'fool-proof'.

*  The program documentation files (*.TXT) was gathered in a new
   subdirectory DOC, leaving only the FDC initialization and installation
   routines in the root directory of the toolbox.

*  The installation routine was improved, allowing installation into a
   different destination directory than C:\FDC12. The self-extracting
   ZIP-file that contained the FDC toolbox distribution files was hidden
   from the user to prevent the files from being installed to a wrong
   directory.

*  A small routine RECOVER.M was created to recover simulation results that
   were not properly sent to the Workspace by Simulink.

*  The initialization routine now added the root-directory of the FDC
   toolbox to the Matlab path in order to allow several routines from FDC 1.2
   to find the default directory settings in the file MODINIT.INI, thus
   reducing the number of 'File not found' errors.

*  A start was made to create an object-oriented implementation of the FDC
   toolbox by putting some often-used parts of programs into general-purpose
   subroutines, but further improvements are still necessary.

*  Slightly modified Simulink models were created for Matlab 4.2/Simulink 1.3.


Version 1.3
-----------
The new version. See WHATSNEW.TXT for more info.


Version 1.4
-----------
Probably the next version. See WHATSNEX.TXT for more info.



References
==========
The main source of information about the FDC 1.2 toolbox is the report:


[1] FDC 1.2 - A Simulink Toolbox for Flight Dynamics and Control
    Analysis. M.O. Rauw, Zeist, The Netherlands, 1996.


In addition, you may still find some useful information in the following
references (although they describe earlier versions of the toolbox):


[2] M.O. Rauw. A Simulink environment for Flight Dynamics and Con-
    trol analysis - application to the DHC-2 'Beaver' (2 parts).
    Faculty of Aerospace Engineering, Delft University of Technology,
    Delft, September 1993. (Also contained in the NASA STAR database
    with report number NONP-NASA-SUPPL-DK-94-28027).

[3] Marc Rauw, Samir Bennani, Hans van der Vaart. An Integrated
    Approach to the Design of Flight Control Systems using CAD Tools.
    Conference proceedings 2AO-94, Paris, November 1994.

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The FDC toolbox. Copyright M.O. Rauw, 1994-2000. All rights reserved.