Welcome To

1
Welcome To Advanced Technology Associates Demons
tration Of An Adaptable Prototype and Test
System For Aerospace Control Software Development
Throughout this demonstration use the right and
left arrow keys to forward or rewind respectively.
Advanced Technology Associates, Inc. (ATA) is a
leading-edge aerospace software and technology
firm that provides both product and service
solutions to the aerospace industry. 
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Objective
Demonstrate how LabVIEW and the ATA Aerospace
Toolkit combine to create a prototype and test
platform that adapts as the project life-cycle
changes.
Iterate/ Reuse
Prototype
Test
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Presentation Outline
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Prototype And Test System High-Level Architecture
Typically engineers use a variety of environments
for development of algorithms. Whatever
environment is used it should be easily
integrated into other environments.
Typically, as GNC laws are defined, they are
coded and tested in an iterative process
characterized by the following high-level
diagram. Each component should be designed to be
highly modular, to maximize code reuse. The
components of the prototype and test system are
shown below.
A 6 DOF simulation of the mission is configured.
The chosen simulation platform should be flexible
and provide easy reconfiguration to allow for
mission changes
A model of the IMU is developed.
The modules are then integrated. In the case of
software-in-the-lopp, this may be as simple as
integrating code modules, or in the case of
hardware, could be physically connecting the
modules and working out communication protocols.
Simulated Vehicle (6 DOF using ATA Aerospace
Toolkit)
GNC (system under development)
IMU model
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LabVIEW and the ATA Aerospace Toolkit as a
Platform for Prototyping and Test
To create a prototype and test system that truly
adapts from one project phase to the next, the
system needs to have 5 characteristics.
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Be Extensible
LabVIEW provides open connectivity with other
environments including C, Ada, and Mathscript, to
name only a few.
Extensible platforms save vast amounts of time.
They allow developers to develop code modules in
the best language suited to the task and then
easily integrate the modules into the prototype
system.
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Be Modular Be Real-Time Capable Be
Hardware Friendly
The PXI is just one solution from National
Instruments which provides high-performance
operation with a modular design, making it an
excellent platform for aerospace prototype and
test applications.
The PXI combines a PC platform with modular I/O
and is an excellent host for running real-time
applications
LabVIEW, with the LabVIEW Real-Time Module offers
a high level development environment , with a
highly deterministic operating system.
National Instruments solutions come complete with
drivers and allow easy integration with diverse
I/O including (analog, digital, a wide range of
data buses and more).
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Be Capable of High-Fidelity Simulation
The ATA Aerospace Toolkit for LabVIEW extends the
LabVIEW graphical development environment. It
gives the user all the functionality needed to
build high-fidelity simulations of spacecraft and
air vehicle flight. The simulation can be easily
deployed to any National Instruments host and can
operate in real-time mode.
Deploy the simulation to a PXI or other National
Instruments real-time capable system for test
Place functions on the panel and wire them
together to create sophisticated, high-fidelity
simulations of spacecraft or air vehicle flight
in minutes.
Select functions such as Compute Acceleration Due
to Drag from the ATA Aerospace Toolkit palette in
LabVIEW
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The ATA Aerospace Toolkit for LabVIEW has 11
comprehensive libraries with over 140 functions.
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This simulation uses the CartesianToKepler
function to convert the position and velocity
vectors from a Cartesian representation to Kepler
elements for display. Kepler elements are often
much easier for humans to interpret.
Creating a high-fidelity simulation requires the
use of multiple time scales and formats. In this
simulation UTC is used for input. The function
ExactTimeUTCtoUTC Date is used to convert from
the UTC format to a date format (yyyy,mm,dd.ddd)
for computational purposes.
In vehicle simulation it is sometimes convenient
to use different attitude representations to
perform different calculations. In this
simulation the QuaternionToDCM function converts
a quaternion used to represent a vehicle attitude
to a direction cosine matrix (DCM)

• This code snippet is part of the 3 degree of
  freedom example included with the ATA Aerospace
  Toolkit. It demonstrates the depth of
  functionality in the ATA Aerospace Toolkit.

In any 3 degree of freedom simulation it is
necessary to propagate the state vector over a
given time interval
In this simulation the ECItoLLH function is used
to convert an Earth Centered Earth Fixed
coordinate frame to a Latitude, Longitude,
Altitude representation
In this example the DCM is then converted to an
Eigen Axis/Angle representation for display.
The Orbit Library contains many functions for
performing orbit alanalysis including Time of
Flight, Line of Sight, Anomaly conversions,
Flight Path Angle and Orbital Elements and
Conversions, including Kepler, Cartesian and
Geoditic.
The Coordinate Frame Library in the ATA Aerospace
Toolkit contains 9 coordinate frames, including
ECI, North East Down, True of Date, Mean of Date
and a high-fidelity frame called ECI J2000
The Toolkit contains a comprehensive time library
with conversion between all the necessary time
formats and scales for high-fidelity simulation
The Aerospace Toolkit has a full suite of
integrators and an orbit propagator featuring a
Runge Kutta 4/5 Adaptive Step Size Integrator
with the ability to select between three gravity
models (Spherical, J2 and Vinit J6) and the
capability to model atmospheric drag.
The ATA Aerospace Toolkit has an extensive Math
Analysis Library that contains functions for
quaternion manipulation, matrix exponential
computation, linear/inverse linear interpolation
and Jacobi matrix diagnalization.
The Math Analysis Library includes attitude
parameterizations such as Quaternions, Euler
angles, Eigen Axis/Angle and Direction Cosine
Matrix.
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Typical Test Project Lifecycle
Development and test of GNC systems can be
viewed as a three stage process.
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During the SIL phase all modules may reside
within a single environment such as a desktop PC.
SIL Test
Note, the use of blue in these diagrams indicates
software. As the system is adapted some of these
components will be replaced with hardware.
The system is characterized and control
algorithms are developed. Algorithms are tested
against a mission simulation. All components are
modeled with software. This process supports
rapid prototyping
At this phase of development the mission
simulation may not be fully refined and does not
necessarily need to operate in real-time.
Any number of development environments may be
used for developing the GNC algorithms including
LabVIEW, MATRIXx, MATLAB, Simulink, C, Ada, which
all have the ability to be called from LabVIEW.
The SIL Test setup is ideal for rapid
proto-typing. Allowing for quick and inexpensive
testing of control algorithms.
Advanced Technology Associates, Inc. (303)
948-7980 www.atacolorado.com
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During the PIL all flight hardware, except the
controller, is still simulated with software.
The same 6 DoF model used during the GNC
algorithm development is again used for PIL
testing. The vehicle simulation is transferred
to a PXI or other platform running a real-time
OS.
The control code has been embedded on the target
and the controller is placed In-The-Loop.
Physical connection is made between the
controller and the platforms hosting the
Simulated Vehicle and the IMU Model.
Note that red denotes hardware or embedded
software.
PIL Test
Control software has been developed and is
embedded on the selected target the controller
is tested In-The-Loop, with the same simulated
vehicle, operating in a real-time environment in
accordance with mission parameters. This allows
the engineer to verify that the controller
operates according with mission specifications.
The output of the IMU is physically cabled to the
controller and the output of the controller is
connected to the real-time system. This verifies
that the GNC control board operates in real-time
and within mission parameters.
The mission simulation built with the ATA
Aerospace Toolkit is modified as needed and
deployed to the PXI to operate in real-time.
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The 6 DoF simulation runs in real-time on a PXI
or other system. The mission simulation is
further refined as needed, to accommodate project
changes.
HIL Test
Additional flight hardware is brought into the
loop to fully test the capability of the
controller
GNC controller has been verified.
The controller has been verified and is now ready
for a system test. The system test will consist
of the GNC controller operating in a closed loop
with the IMU. These components will fly in a
high-fidelity simulation in accordance with
mission parameters.
Some tests can only be performed once (such as
the firing of a rocket motor). In such cases
there are great advantages to using a modular,
adapting test system for development. Using such
a process ensures that components and connections
are verified in a system that is as like the
environment of the final test as possible, prior
to the final test event.
HIL Testing is an expensive and time consuming
proposition. As much work and testing as
possible should be done before reaching this
stage of development. Setting up an efficient
SIL and PIL system will allow developers to work
out problems before integration, lowering cost
and reducing risk.
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Summary

• A good prototype and test system will be capable
  of adapting to meet the project life-cycle
  requirements.
• The ATA Aerospace Toolkit extends the LabVIEW
  graphical development environment, allowing the
  user to build high-fidelity spacecraft and air
  vehicle simulations for prototyping and test.
• LabVIEW, the modular National Instruments
  platforms (like the PXI) and the ATA Aerospace
  Toolkit combine to provide an excellent
  integrated solution for control software
  prototyping and test.

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Want to Know More?

• Learn more about the ATA Aerospace Toolkit.
  www.atacolorado.com/aerospace_toolkit.htm
• Download the ATA Aerospace Toolkit and try it
  free for 30 days. www.atacolorado.com/downloads.ht
  m

• Learn more about National Instruments LabVIEW
  graphical development environment or other
  embedded design and test solutions.
  www.ni.com