Welcome To Advanced Technology Associates Demonstration Of An Adaptable Prototype and Test System For Aerospace Control Software Development Advanced Technology

Welcome ToAdvanced Technology Associates’

Demonstration Of An Adaptable Prototype and Test System For Aerospace Control Software Development

Advanced Technology Associates, Inc. (303) 948-7980 www.atacolorado.com

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.

Throughout this demonstration use the right and left arrow keys to forward or rewind respectively.

ObjectiveDemonstrate how LabVIEW and the ATA Aerospace Toolkit combine to create a prototype and test platform that adapts as the project life-cycle changes.

PrototypeIterate/ Reuse

Test

Presentation Outline

Typically, as GN&C 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.

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.

Prototype And Test System High-Level Architecture

GN&C(system under development)

SimulatedVehicle

(6 DOF using ATA Aerospace Toolkit)

IMU model


Typically engineers use a variety of environments for

development of algorithms. Whatever environment is used it should be easily integrated

into other environments.A model of the

IMU is developed.

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

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.

LabVIEW provides open connectivity with other environments including C, Ada, and Mathscript, to name only a few.

LabVIEW

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.

Be Extensible

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).

LabVIEW, with the LabVIEW Real-Time

Module offers a high level development

environment , with a highly deterministic operating system.

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

• Be Modular • Be Real-Time Capable • Be Hardware Friendly

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.

Select functions such as Compute Acceleration Due to Drag from the ATA Aerospace

Toolkit palette in LabVIEW

Place functions on the panel and wire them together to create sophisticated, high-

fidelity simulations of spacecraft or air vehicle flight

in minutes.

Be Capable of High-Fidelity Simulation

Deploy the simulation to a PXI or other

National Instruments real-time capable

system for test

The ATA Aerospace Toolkit for LabVIEW has 11 comprehensive libraries with over 140 functions.

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.

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 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 Toolkit contains a comprehensive time library

with conversion between all the necessary time formats and

scales for high-fidelity simulation

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 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.

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)

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.

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 any 3 degree of freedom simulation it

is necessary to propagate the state vector over a given

time interval

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.

Typical Test Project Lifecycle


Development and test of GN&C systems can be viewed as a three stage process.

At this phase of development the mission

simulation may not be fully refined and does not necessarily need to operate in real-time.

SIL Setup

GN&C Algorithm

(system under test)

SimulatedVehicle

(6 DOF with ATA Aerospace Toolkit)

IMU model

SIL TestSIL Test


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

Note, the use of blue in these diagrams indicates software. As the system is

adapted some of these components will be replaced with hardware.

During the SIL phase all modules may reside

within a single environment such as a

desktop PC.

The SIL Test setup is ideal for rapid proto-

typing. Allowing for quick and inexpensive testing

of control algorithms.

Any number of development environments may be used for

developing the GN&C algorithms including LabVIEW, MATRIXx, MATLAB, Simulink,

C, Ada, which all have the ability to be called from LabVIEW.

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.

PIL Setup

GN&C Control Board

(system under test)

SimulatedVehicle

(6 DOF model using ATA Aerospace Toolkit)

IMU Model

PIL TestPIL Test


Note that red denotes

hardware or embedded software.

The same 6 DoF model used during the GN&C 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 mission simulation built with the ATA Aerospace Toolkit

is modified as needed and deployed to the PXI to operate

in real-time.

During the PIL all flight hardware,

except the controller, is still simulated with

software.

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 GN&C control board operates in

real-time and within mission parameters.

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.

HIL Setup

GN&C Control Board

(system under test)

SimulatedVehicle

(6 DOF model using ATA Aerospace Toolkit)

Flight HardwareIMU

HIL TestHIL Test


The controller has been verified and is now ready for a system test. The system test will consist of the GN&C controller operating in a closed loop with the IMU. These components will “fly” in a high-fidelity simulation in accordance with mission parameters.

GN&C controller has been verified.

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 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.

Additional flight hardware is

brought into the loop to fully test the capability of the controller

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.

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.


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.htm

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

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Welcome To Advanced Technology Associates Demonstration Of An Adaptable Prototype and Test System For Aerospace Control Software Development Advanced Technology