FIDO - Framework for Interdisciplinary Design Optimization
A Programming Environment for Distributed Complex Computing
Objective: The Framework for Interdisciplinary Design Optimization
(FIDO) project is developing a general computational environment for performing
automated multidisciplinary design and optimization (MDO) using a heterogeneous
cluster of networked computers.
FIDO's integrated design and optimization approach avoids a common practice in the past
where a new design is passed from one discipline to another with little communication
as each designer tried independently to reach an optimum.
The initial implementation of the FIDO system has been a simplified-model
demonstration of a High-Speed Civil Transport (HSCT) optimization for cruise.
However, the FIDO system is being designed to be generic enough to handle
with minimal modifications any design problems that require input
from a number of specialty disciplines.
is organized into distributed service, computational, and auxiliary segments, which
communicate through a communications library (based on PVM)
that forms the backbone of the system.
The service segments are the executive, an associated graphical user interface (GUI),
the master task controller, the data manager, and the communications library.
The computational segments consist of the discipline codes required for a particular
problem. The discipline codes are usually existing codes, often in Fortran, which must
be interfaced to the FIDO system through C-language drivers that use the communications
library to transmit data and control signals.
(For the HSCT design, these disciplines include aerodynamics, structures,
propulsion, performance, optimization, and interdisciplinary data conversion.)
The main auxiliary segments consist of the primary GUI that monitors FIDO system
status, and an interrogatory code
(called SPY), which provides access to the centralized database
for viewing results during the computations.
SPY also includes a provision for steering the design process by allowing the operator
to change certain control variables at the end of any cycle.
An additional auxiliary segment provides a GUI for initial problem setup.
Each segment is assigned to the computer type most appropriate for it
in the heterogeneous cluster.
All of the computers are networked together, have access to centralized data,
and work on their parts of the design simultaneously, in parallel
The software is written in modular form to ease migration to upgraded
or completely new problems.
The executive, GUI, data manager, SPY, and communications library are all
designed to be generic, deriving necessary problem information from configuration
files; they should not have to be rewritten as problems change.
Also, different codes can be substituted for each of the current discipline
code modules with little effect on the others.
Only the master must be substantially rewritten in order to control
the sequencing of tasks automatically for each different problem.
Accomplishments:The FIDO system has demonstrated optimization for a simplified
HSCT design problem on a network of UNIX(R) workstations (six Suns and one SGI)
with monitoring and graphics display through "SPY"
and the use of flexible file-based data management.
This figure shows results from FIDO for the simplified
HSCT wing design demonstration problem.
There are three planform design variables (inboard leading-edge sweep angle,
root chord length, and spanwise break location)
and two structural design variables (inboard and outboard panel thicknesses).
The upper left plot shows the evolution of these five variables
over twenty design cycles --
note that sweep and root chord quickly reach their preset limits.
A sequence of corresponding planforms is shown at the right.
Although the design reached is clearly infeasible due to unrealistic constraints,
the system functioned properly within the constraints set for it.
The resulting objective (weight minimization) is in the middle left of the figure,
and several analysis variables are plotted in the lower left.
The total time to complete these twenty cycles was about three hours.
Significance: Many design problems require inputs from a number
of specialty disciplines.
The points of view, design emphasis and design approaches
of the discipline specialists can be quite diverse.
The FIDO system facilitates communications between the computational tasks
involved and provides a means for partially automating the total design process.
At the same time it provides the designer (and consultants) with means
for interactively viewing intermediate results and guiding the process.
It should be possible to reduce the time per design cycle from many weeks to days or
hours, allowing a more optimal design to be reached within given time constraints.
REFERENCE: Townsend, J.C.; Weston, R.P., and Eidson, T.M.: A Programming
Environment for Distributed Complex Computing. An Overview of the Framework for Interdisciplinary Design Optimization (FIDO) Project. NASA TM 109058, December 1993.
FIDO Concept Originator and Project Designer:
Point of Contact:
Last Updated Wednesday, April 17, 1996
- Robert P. Weston
- NASA LaRC - MDO Branch
- 18c West Taylor St. - M/S 159
- Hampton VA 23681-0001
- (804) 864-2149 FAX: (804) 864-9713