The Flight Dynamics and Control Toolbox - Roadmap: past and future
==================================================================
Welcome to the FDC development roadmap. This document describes where the FDC
toolbox has been, where it is today (in the new version 1.4), and where it
might be going to in the future.


FDC 1.0 - where it all started
==============================
The first instance of this toolbox was created all the way back in 1992 at the
Faculty of Aerospace Engineering of Delft University of Technology. At the
time, the Faculty was about to retire its old DeHavilland DHC-2 Beaver
laboratory aircraft, and one last round of flight tests were reserved for an
autopilot design project of the Section Stability and Control. As the
retirement date was already set firmly, the autopilot would have to be ready
for real flight in a very short time, i.e., all control laws would have to be
drafted from scratch, fine-tuned using conventional design methods, and
validated in a series of nonlinear simulations. Quite an impossible task, had
it not been for the availability of Matlab, the Control System Toolbox, and
the (then new) Simulink simulation package.

Those circumstances laid the foundation for the development of the FDC
toolbox. A first public presentation of a collection of Matlab and Simulink
tools for the autopilot project was made at the end of 1992; the first
'finished' version of those tools was released as part of the MSc-thesis of
the author in september 1993 [Rauw, 1993]. That first 'finished' version has
later been dubbed 'FDC 1.0', in order to provide a clear overview of the
history of the toolbox.


FDC 1.1, 1.2, and 1.3 - opening the toolbox to a wider audience
===============================================================
Realizing that this toolbox might also be useful for other projects, it was
decided to create an improved version that would target a much wider audience.
The idea was to provide some significant improvements in the model structure
and user-friendlyness of the software, and to create a new user-manual that
would be better suited as both a tutorial and reference guide than the
existing MSc-thesis, but eventually the development stalled due to lack of
time. The only visible results from this excercize were a locally distributed
beta-version of the package, and a presentation of a research paper at the
2AO-94 conference in Paris [Rauw et al., 1994]. The beta version was dubbed
'BEAST 1.1 beta'; BEAST being an acronym for 'Beaver Simulation Toolbox'.

Although this version never made it to the general public, it did lay the
foundation for the Flight Dynamics and Control Toolbox version 1.2, which was
released at the end of 1996 and distributed over the FTP-servers of The
Mathworks in april 1997. Later that year, FDC 1.3 was released, to counter
some compatibility problems related to the new Matlab 5 / Simulink 2 versions
and to take advantage of the newly introduced support for webbrowsers (which
yielded a huge improvement in the on-line help system). Finally, on april 1998
the first version of the FDC website was made public, finally realizing the
1994 ideas of providing a useful software-tool for as wide an audience as
possible.


What happened next?
===================
Since the release of the FDC website, the response has been truly
overwhelming. A new, long-term plan was made to create an all-new version of
the toolbox which would eliminate as many fundamental shortcomings in the
current FDC 1.x design as possible and which would be even more accessible to
an even wider audience. Although the 'FDC 2' development would have to take
place entirely in the spare time of the author, the release date for this
significant new version was still targeted somewhere around 2001... which gain
proved to be _way_ too optimistic: even today, February 2005, a truly mature
FDC 2 still seems to be a _long_ way off.

However, over the years some small improvements were introduced in the FDC 1.3
tree (yielding Service Release 1, Service Release 2, and finally FDC 1.3.3),
and the design of the website has been improved dramatically. Also, the
project was moved to the dutchroll.com and dutchroll.org domains, the project
files were moved to SourceForge, the original MSc-thesis which started the
whole project was scanned and published as PDF file or printing-on-demand
report, and a small derivative work from the FDC 2 development was made public
as the Dutchroll Blockset for Simulink (DUBSI).


FDC 1.4 and 2.0 - the latest update and long-term future
========================================================
This new release would never have been created if the FDC 2 project would have
been feasible. However, with the current delay it was decided to continue the
FDC 1.x branch, in order to fix at least some of the most urgent problems in
the previous version. Hopefully, this interim update will help to keep the FDC
toolbox relevant for the near-term future, despite its somewhat ageing code-
base, which is still largely based on the Matlab 3.5 and Simulink 1.2
capabilities. The FDC 1.4 release will be accompanied by a major revision of
the FDC user-manual, replacing the FDC 1.2 report which is starting to show
its age.

The FDC 2 project will remain the long-term focus for the FDC toolbox. In
order to prevent another stall in FDC development due to the sheer magnitude
of this project, it is likely that an evolutionary, rather than a
revolutionary approach will be taken. This means that more 1.x versions will
probably be released first, and that the identified shortcomings will be
eliminated one at a time.

The main focus will be on improving the structure of the programs, separating
user-interface from analytical subroutines. Other points of interest are the
development of a graphical user-interface, an improved model structure which
offers much more flexibility in the I/O level, an improved library structure,
and improved HTML helpfiles that will include relevant equations and/or
graphics. This should make it a lot easier to implement models of other
aircraft in the FDC structure, which needs to be demonstrated for a wide range
of aircraft models, if possible. Several model enhancements are also planned,
such as explicit handling of turbulence within the aerodynamic model, a choice
between Euler angles and quaternions for attitude representation, more
practical ILS, VOR, and turbulence modelling (more in line with a pilot's
point-of-view), a units-conversion library, an analytical routine for the
derivation of stability and control derivatives, etc.

It remains to be seen whether or not these plans will ever materialize, but
gradual improvements will certainly be implemented, starting with the
integration of some FDC 2.0 work that already has been done.


-------------------------------------------------------------------------
The FDC toolbox. Copyright M.O. Rauw, 1994-2005. All rights reserved.
This software is licensed under the Open Software License, version 2.1.
See the file copying.txt in the DOC subdirectory for detailed information
about the terms of use.
-------------------------------------------------------------------------
