Planning and Executing an Integrated Test Strategy for ... · PDF filePlanning and Executing an Integrated Test Strategy for ... Copyright © 2012 by Lockheed Martin Corporation. ...

1Copyright © 2012 by Lockheed Martin Corporation. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission

Planning and Executing an

Integrated Test Strategy for

Complex Aerospace SystemsLockheed Martin Perspective

Ming ChangSeptember 11, 2012


Insight to Successful Complex System

Development

• Successful system development is dependent

on understanding system requirements

− Clarity of the requirements

− Achievable requirements

• Feasible design (closed concept) with which to

start Preliminary design

− Affects of design choices

− Affects program cost and schedule

• Early identification of risks

− Defines Trade studies

− Defines test and validation program


Flight Vehicle Systems Life Cycle

Cost

Life Cycle Costs are Locked in During the Up-Front Design & Development Process


Top Level Perspective of LM T&E for

Flight Vehicle Systems

CD PD EMD/FSD DT&E/OT&EOper.TRL 2-3

SRR SRDPDR CDR FRR

Typical Activities• Operational

need/Requirements

definition

• Concept trades

• Concept sizing &

design

• IRAD activity

adaptation &

transition

• System downselect

• Initiate M&S

• Diagnostic testing

• Coupon testing

• Risk ID

Needed Additional

Activities

• In-depth trade

studies

• Utilize DoD

Willoughby templates

as guidelines

Product

Feasible DesignProduct

Matured Design

Typical Activities• Requirements

definition & refinement

• Trade studies

• Concept sizing &

refinement

• IRAD transition

• Component testing

− Bench test

− Coupon test

• M&S development

• Preliminary testing

− WT test

− Engine test

• Risk assessment &

mitigation plan

• FT planning

• Ground test planning

• SIL & HIL test

planning

• Initiate Willoughby

template process

TRL 4-5 TRL 6-7 TRL 8-9Cert.

Typical Activities•Concept development &

refinement

• Trade studies

• Risk analysis and management

• IRAD transition

• Configuration control

• M&S refinements & updates

− Aerodynamic

− Propulsion

− Mass properties

− …

• Development testing

− WT test

− real time simulation

• Risk assessment & mitigation

plan

• Detailed FT planning

• Ground test

• Component/subsystem test &

integration

• SIL & HIL test

• Willoughby template process

Product

Drawing Release

Product

System Certification

Typical Activities• FT execution

• M&S refinements/updates &

validation

− Aerodynamic

− Propulsion

− Structural

− Mass properties

− …

• Performance updates

• Envelope expansion and

validation

• System certification testing


Basic Steps of Controls System

Development

• Requirements

• System Level

• Software

• Hardware

• Interface

• Design

• System Architecture

• Software Mechanization and Models

• CPU and I/O hardware Schematics

• Bus Topology and Payload definition

• Implementation

• System Model

• Code or S/W Model

• H/W manufacture

• Bus Model

• Integration

• System Level integration

• Software/Hardware Integration

• S/W Model autocode to Hardware

Integration

• Bus Integration

• Test

• System Level V&V

• Software Level V&V

• Hardware Qual Testing and SOF Testing

• Interface V&V


Flight Control / VMS V&V

Model V&V •Control Power V&V

•Control Law V&V (Stability, Performance, Robustness)

•Functional V&V (Model Checking: FM, RM, IM, BIT, CLAW Modes)

Software V&V•Unit/Component Test

•Hardware/Software Integration (HSI)

Hardware V&V•Qualification Test (Safety of Flight)

•Aircraft Integration

System V&V•Standalone (Static)

•Integrated (Dynamic)

•Failure Modes and Effects Test (FMET)

DISCIPLINE

S&C

CLAW

SYS

SW

HW

TEST

V&V TYPE

V&V is Pervasive Throughout Entire System Development Process


Flight Control Development &

Certification Summary• Safety has been first and foremost since the introduction of Software into Flight Control

Systems

– Safe System Development and Operation are the Result of:

• Certification Process

• Team Experience and Drive

• Resource Availability

• Management Practices and Commitment

• Appropriate Tools, Methods, Processes, Technology

– SOF Certification is accomplished on all LM Aero programs via our In-house processes

• Following Appropriate Design Processes

• Working with Air-Worthiness Criteria throughout the process

• Independent Standalone Validation

• Integrated System Test

• Failure Modes and Effects Testing

• Process is Critical to our Approach

– Based on previous Mil-Stds (e.g. 2167) and Commercial Processes ( e.g. SEI Level 4)

– Current Customer Air Worthiness Standards

– Matured with Key in-house elements

Success Enabled by Maintaining “Cradle-to-Grave” Mentality and Culture


Software V&V

Inte

gra

tion

& V

erific

atio

n/V

alid

atio

n

Software Code

Build, Code, Unit Test

Software code and unit test

Component Inspection and Test

Software inspection and test,

modeling and simulation, system

integration lab testing of components

Software Test Reports

System Integration

Subsystem/Configuration item qualification,

modeling & simulation and system

integration lab testing, verify specification

requirementsSystem Integration / Qual Test Reports

Integrate,

Fix, Test

Integrate,

Fix, Test

System Verification Reports

System Verification

Developmental test & evaluation ground

test,

verify integrated system meets

specification

Integrate,

Fix, Test

System Validation

Transition to operational test & evaluation

to validate system performance against

user needs

Operational Assessments

Integrate,

Fix, Test

Unit Test Design

Component Test Design

Integration Test Design

System Functional Design

System Performance


Hypersonic Vehicle Structural

Modeling Process

Basic

geometry

Basic geometry

Configuration

Initial System

and Structural

LayoutStructural FEM

External Loads

Model

Time dependent

thermal results

Thermal FEM

Time dependent

external loads

Bending Moment Versus Buttline Station

-100.0E+3

000.0E+0

100.0E+3

200.0E+3

300.0E+3

400.0E+3

500.0E+3

600.0E+3

-150 -100 -50 0 50 100 150

Buttline (inches)

Ben

din

g M

om

en

t (i

n-l

bs)

Shear Versus Buttline Station

-10.0E+3

-8.0E+3

-6.0E+3

-4.0E+3

-2.0E+3

000.0E+0

2.0E+3

4.0E+3

6.0E+3

8.0E+3

10.0E+3

-150 -100 -50 0 50 100 150

Buttline (inches)

Sh

ear

(lb

s)

Shear Versus Fuselage Station

-10.0E+3

-5.0E+3

000.0E+0

5.0E+3

10.0E+3

15.0E+3

20.0E+3

0 100 200 300 400 500 600 700

Fuselage Station (inches)

Sh

ear

(lb

s) Bending Moment Versus Fuselage Station

-900.0E+3

-800.0E+3

-700.0E+3

-600.0E+3

-500.0E+3

-400.0E+3

-300.0E+3

-200.0E+3

-100.0E+3

000.0E+0

100.0E+3

0 100 200 300 400 500 600 700

Fuselage Station (inches)

Ben

din

g M

om

en

t (i

n-l

bs)

Combines:

1) Structural Arrangement with

2) Mission segment thermal

results, and

3) Mission segment external

loads

Basic geometry and

structural arrangement

Structural Design

Criteria

Results

1) Improve weight estimates

2) Internal loads

3) Direction for refined design


Hypersonic Vehicle Key Features

Layout for Study

Engine(s) at lower

mid-fuselage

Fuel tanks

Avionics/Subsystems

Additional Subsystems

•The vehicle finite element model captures all key elements of the vehicle

layout for structure optimization:

•Fuselage/engine integration

•Fuel tank integration

•All subsystems and thermal balance

•Provisions for cargo

•Control surfaces and fuselage integration

• Integration of the overall vehicle stiffness contributions from the various

vehicle elements (listed above) is essential and critical for modeling and

simulation of the vehicle’s overall structural response


Conclusion

• Flight Safety is foremost for any ADP program

• Validation is a continuing process throughout

the program

− WT testing: diagnostic, exploratory &

production

− Structural: component/coupon testing,

indepth FEM modeling

− Unit Testing for VMS software

• Verification

− Real time simulations

− Pilot in loop simulation

− Integration testing with SIL & HIL


BACK UP CHARTS


Hybrid Aircraft Demonstrator Program

On-Board Weather

Monitoring & Route Planning

High Strength Fabrics

Air Cushion

Landing System

Thrust Vectoring

Propulsion

• 80% Lift From

Buoyancy

• 20% Lift From Aero

• Extremely Efficient

Transportation

Benefits of Hybrids• Direct Delivery

to Objective

• Land in Austere

Environment

• Decreased Fuel

Consumption

• Increased Payload

Hybrids Transform Transportation


Hybrid Airship Path Forward

2006 2013 2014-15First

Flights2016-18

• Tech Demonstrator

• 120’ Long, Piloted

• Full Vectored Thrust

• Digital Flight Control

• Hover & Grip ACLS

• Specialty Lift / ISR

• Remote Access

Missions

• Full Vectored Thrust

• Digital Flight Control

• Hover & Grip ACLS

• Scalable to Heavier Lift

• Tactical Operations

• 50+Ton Payload

• 2000nm Range

• Remote Operations

• Take-Off & Landing From

Unimproved Land or Sea

• Low Operating Costs

(Under A/C)

• Strategic Operations

• 500+Ton Payload

• 6000nm Range

• Ocean-Going

Containerized Freight

• Brigade Scale Military

Deployments

• Take-Off & Landing

From Unimproved

Land or Sea

• Low Operating Costs

(Near Ships)

• Global Reach Ops

• 20 Ton Short

Haul Lift Missions

• Persistent ISR

• Global Heavy Lift

• Units of Action From

CONUS Direct to Objective

• Rapid Sealift – Over Land!

• Port Independence

• Regional/Tactical Lift

• Direct Delivery to

Objective Transport

• Fleet Re-Supply

• Search & Rescue

• Tech Risk Reduction

• Cost/Schedule

Scaling & Proof


The World’s View

To most of the world, P-791 appeared in January 2006, when this video appeared

on YouTube

For us at Lockheed Martin, the idea started more than a decade earlier…


P-791 Program Approach

Minimum Size for Similarity to Operational Vehicle

Low Cost

Off-the-shelf Components Wherever Possible

Complete in ~ One Year

Programmatic

Focus On Key Risk Drivers

Enable Validation Key Parametric Variables In System Model

Size Vehicle To Replicate All Critical Functionality

Technical Demonstrate Ground Ops

Without Line Handlers

Evaluate Flyability

Evaluate Control Interface

Develop Ops Procedures

Operational


Envelope Shaping

• Blend of Aerodynamic and Buoyant Lift

• Evaluated numerous fully smoothed (rigid structure) and lobed

(non-rigid) complete preliminary design configurations

(Aerocraft 1997-2001)

• Non-rigid by far the lightest (and least costly) at all scales

• Lobed shapes integrated best at 3 lobes

• Lofting for minimum weight and reasonable aerodynamics is

tricky


Envelope Design – Aero Shaping

• Shapes that look very similar have

vastly different aero properties

• Small changes to aft region can

multiply drag by 3-4 times if not

considered carefully

• Aft propellers have limited effect in

reducing separated flows and extra

weight not offset by fuel savings

Baseline Profile TE Down 5ft

TE Down 8ft TE Down 10ft

CATIA lofts run through rigorous aerodynamics

modeling for performance validation

First pass for pressure forces via QuadPan (inviscid)

Detailed passes with full Navier-Stokes solver to detail

viscous effects, separation regions, propeller

influences, etc


Vehicle Level Analysis - Structures

• Tensys Numeric Model

– Original Model

Created for 410

Configuration

– 501 and 502 Updates

• Load Cases

– Flight Conditions

– Landing Dynamics

• Criteria

– FS = 4.0 Global

• Results

– Positive Margins for

Selected Fabric

– Sufficient Stiffness for

Tail Loads

HOOP STRESS

LONGITUDINAL STRESS


Structural Integration Examples

(Non-Propulsion)

Gondola

Lacing Track

Air Cushioned

Landing System Pads

Horizontal StrakesTiedown Point


Air Cushion Landing System (ACLS)

ACLS system used for

takeoff/landing, taxi and parking

ACLS allows operations on

unimproved surfaces including

snow, ice, and water

ACLS has both taxi and grip modes

and is fully retractable

Low plenum pressure (<0.3 psi)

Grip tested in 25 knot winds

ACLS Pad in Grip Mode ACLS Pad in Hover Mode


Test Rig and Model Pad

• One of a kind test rig

• Allows variable pad weight and inertia, with full 360°rotation capability to simulate real landing cases

• Fully integrated high speed data acquisition system


Yaw

Pitch

Thrusters

Yaw

Pitch

Thrusters

Yaw

Pitch

Thrusters

Thruster Design / Description• Thrust

– 480 lb (Sea Level Static, Uninstalled)

– Directable To ±90° In Yaw, ±90° In Pitch

– Nominal Rate of 45°/s

• Systems

– Engine

• 100 hp Four Cylinder Two-StrokeHirth F-30-ES; Fan Cooled

– Propeller

• 60”, 3 Blade, Fixed Pitch Powerfin Prop

– “Pusher” Configuration

– Actuation

• Moog Rotary Electromechanical Actuators

• Volz DA 20-30-4124 Servos For Throttle Control– Control - Thruster Control Unit (TCU)

• Embedded PC-104 Computer

• Commands from VMC via RS-422

• Controls Yaw & Pitch Gimbal Actuators, Throttle Servo

• Hardware Design, Software Provided by VMS

– Instrumentation

• Grand Rapids Avionics Engine Monitoring/ Instrumentation System (CHT, EGT, RPM, Fuel Pressure)

• Two Triax Accelerometers on Engine

• Vertical Axis Accelerometer on Lower Engine Mount Yaw Axis

Pitch

Axis

Forward Mount

Thruster

Unit

Thrust Vector

Requirements

Shown Here At:

+90° Yaw,

0° Pitch


Thruster Test Rig

Design start –

Jan 05

4 thrusters ATP’d

and installed

Dec. 05


Pilot-in-the-Loop Simulator

Complete Buoyant

Physics 6-Degree-of-

Freedom Simulator

Built Specifically for

and Dedicated to

Hybrid Airship

Development

Gives Unique Insight

Into Handling Qualities

in Stressing Maneuvers

and Conditions (Stage

III turbulence, etc)


P-791 Changed the Game for

Hybrid Aircraft• Five Years Ago, Quietly, P-791

Validated All Technologies Required for

Hybrid Aircraft

• P-791 Provided Data Critical to

Validating Design and Analysis Tools

• P-791 Verified Safe Piloted Operations

of a Hybrid Aircraft

Primarily as a result of the P-791

success, Lockheed Martin

became convinced of the

feasibility of Hybrid Aircraft

and will design, build, certify

and stand behind operational

Hybrid Aircraft serving a

variety of customer needs

Planning and Executing an Integrated Test Strategy for ... · PDF filePlanning and Executing an Integrated Test Strategy for ... Copyright © 2012 by Lockheed Martin Corporation. ...

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