Transcript Slide 1

Air Force Research Laboratories
Integrity - Service - Excellence
Automated Aerial Refueling:
Extending the Effectiveness
of Unmanned Air Vehicles
Jacob Hinchman
Program Manager
Automated Aerial Refueling
[email protected]
Integ
r i t y - A:SCleared
e r v i For
c e Public
- E xRelease
cellence
Distribution
Significance to Air Force
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Unmanned Aerial Vehicles
– Extends Range
– Shortens Response for Time-Critical Targets
– Maintains In-Theater Presence Using Fewer
Assets
– Deployment with Manned Fighters and Attack
Without the Need of Forward Staging Areas

“We will leverage long-range
and stealthy assets to
ensure we can access any
target and quickly defeat
enemy defenses to allow
other forces to operate.”
Global Strike Vision
Manned Aircraft
– Provides Adverse Weather Operations
– Improves Fueling Efficiency
– Reduces Pilot Workload
AAR Will Assist UAVs in Reaching Their Full Potential
and Greatly Enhance Manned Refueling
PA #: AFRL/WS-04-1076
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AAR Program Key Aspects
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Automating the Receiver
- Demonstrate an Operationally Feasible UAV
Refueling Capability
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Near-Term Focus – Boom/Receptacle
Refueling
- Target was Air Force UAVs
- Near-Term Refueling Requirement
- Challenge Technology Base
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Future Application to Probe Drogue Refueling
- Leverage Tech Base Developed in B/R
- More Challenging “End-Game”
Crawl, Walk, Run Spiral Approach to Provide
Timely Technology Transition
PA #: AFRL/WS-04-1076
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Boom/Receptacle Refueling
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PA #: AFRL-WS 05-1166
From the Receiver’s Perspective
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Close Formation Flight
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Follow Tanker’s Lead Around
Refueling Track
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Can Take up to 30min for Heavy’s
From the Tanker’s Perspective
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Tanker Flies in a Predictable Manner
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Boom Operator Flies Boom into
Receptacle
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Tanker Control Fuel Offload and Rate
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Probe/Drogue Refueling
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From the Receiver's
Perspective
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Fly Formation with Tanker
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Capture the Drogue/Basket
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Push Basket Forward for Fuel
to Flow
From the Tanker’s
Perspective
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Fly in a Predictable Manner
PA #: AFRL-WS 05-1166
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National AAR Team
ACC
ASC
AMC
Navy
SynGenics
Corporation
PA #: AFRL/WS-04-1076
Integrity - Service - Excellence
©
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Key Technology Challenges
See Near
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Determine Relative Position with Tanker
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Using Position/Velocities to Close Control Loop
High Confidence in Position Accuracy
Avoid Aircraft in AAR Area
Collision Avoidance
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AAR Brings Many Aircraft into Same Airspace
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Moving from ARIP to ARCP
Command and Control
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Assure UAV Accurately Responds to Boomer BreakAway Commands
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Commands are Flight Critical
Real World Considerations
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Fitting Solutions into a Low Probability of
Detect/Intercept Environment
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PA #: AFRL/WS-04-1076
Latency, Drop-Outs, Re-Encryption, and Limit Power
Settings
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Key Challenges:
Integration of Technologies
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Refueling Affects Most Aircraft
Systems
- Fuel, Navigation, Flight Controls,
Sensing, Comm, and Ground Station
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Pilot in Command Issues
- Ground Station has Limited Situational
Awareness
- Data Latencies due to Datalink Delays
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Autonomy of Vehicle Increases
- Fault Detection and Safety need to be
On-Board
Dist A: Public Released
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Technologies Needed
- Formation Flight
- Automated Collision
Avoidance
- Precision Positioning
- Tanker to UAV Comm
- Ground Station SA
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Mission Profile
Dist A: Public Released
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The CONOPS
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Working with ACC & AMC to
Develop CONOPS
Used F-16 Procedures As Baseline
Refueling 4-Ship UCAS Packages
Manned Refueling Procedures
Extensive use of simulation to
validate and demonstrate
CONOPS to warfighter
Based AAR Procedures On Current Manned Aircraft Procedure
Ensuring Seamless Integration, Ease Transition
Public Release #: ASC 04-1036
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Example CONOPS:
Contact Position
Authorized UCAS Stabilizes in PreContact Position
Boomer Authorizes UCAS to Contact
Position
Authorized UCAS Stabilizes in Contact
Position
Boomer Plugs UCAS
UCAS Acknowledges Contact to MCS
Operator
Confirmation of Contact Is Provided to
Tanker
UCAS Maintains Contact Position
UCAS Takes Fuel
Dist A: Public Released
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AAR Conceptual Design Families
Navigation-Based
Advantages:
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Lowest Technical Risk For Initial Capability
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All Weather Capability
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Compatible With Navy Ops
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Simple Vehicle Integration
Disadvantages:
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Requires Tanker Modifications
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Susceptible to GPS Degradation
Public Release # : ASC 04-1271
Sensor-Based
Advantages:
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Most Affordable Conceptual Design
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Sensor May Enable Additional UCAS
Capabilities
Disadvantages:
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UCAS Vehicle Integration
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Sensor Development Risk
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An Equivalent Model for
UAV Automated Aerial Refueling Research
Dist A: Public Released
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Planform & Control Surfaces
Equivalent Model
ICE 101
Wing Area 808.6 sq ft
Wing Span 37.5 ft
Body Length 43.12 ft
Leading Edge Sweep 65 deg
AR 1.74
Wing Area 808.6 sq ft
Wing Span 54.7 ft
Body Length 29.6 ft
Leading Edge Sweep 42.8 deg
AR 3.7
Leading Edge Flaps
Spoiler Slot Deflector
Clamshell
(Yaw & Speed Brake)
Clamshell
All Moving Tip Deflector
Flap (Pitch)
Aileron (Roll)
Pitch Flap
Elevon
Dist A: Public Released
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Equivalent Model Initial Agreement
Model will be non-proprietary
The ICE aspect ratio will be modified to a value of 3.7
To properly model gust sensitivity in the pitch axis, wing loading
will be adjusted to 50 lb/ft2
Control power will be modeled as required to meet acceleration
requirements and provide a predictable, linear, inner-loop response
Control surface effectiveness and interactions will be simplified since
control allocation is not the focus of this effort
Dist A: Public Released
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Flight Limits and Airframe Response
Flight Envelope
Total Fuel Weight = 17,500 lbs
Total Gross Weight = 40,430 lbs
Altitude: 20K to 30K
Airspeed: 225 KCAS to Mach 0.8
Angle of Attack: -5° to +10°
Side Slip Angle: +/- 5°
Short Period, Roll, and Dutch Roll Mode Response
Pitch time to double - neutral
Roll - stable
Yaw time to double - neutral
Acceleration Response
Pitch
5.52 rad/sec2
Roll
7.84 rad/sec2
Yaw
1.17 rad/sed2
Deceleration 12.35 ft/sec2
Dist A: Public Released
(independent use of full pitch flaps)
(independent use of full elevons)
(independent use of one clamshell)
(independent use of both clamshellsassumes no yaw input)
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Target Closed Loop Dynamics
Longitudinal Axis
Short Period Frequency
Short Period Damping
4.5 rad/sec
0.8
Roll Axis
Bank Frequency
Bank Damping
2.2 rad/sec
0.9
Note:
Stability margins of 6 db and 45°
to be maintained with guidance
loops closed
Directional Axis
Dutch Roll Frequency
Dutch Roll Damping
1.5 rad/sec
0.8
Speed Control
Speed control requirements will be developed as part of the AAR
contract. Use of modulated speed brakes will only be pursued if
it is determined adequate control can not be achieved through
use of engine control alone
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Role of Flight Simulation
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Integrated Aerial Refueling R&D Simulation Being
Developed
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PC Based Simulation
Boomer Station
UAV Operator Station
Tanker Pilot Cube
Other Receiver Stations
Infinity Cube Simulation
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Provides Test Bed for AAR System Development
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Allows Rapid Prototyping and Early Operator
Interactions
Helps Develop and Visualize Correct Story
Boards
Facilitate Early Operator Interaction with the AAR System
Dist A: Public Released
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Simulation Structure
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Simulation consists of five main components
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Simulation control console
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KC-135 boom operator station
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KC-135 pilot station
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UAV operator station
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Observer-Referee station
D-Six stations
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Windows-based, real-time simulation environment
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Includes four UAVs, KC-135 tanker, and boom model
Dist A: Public Released
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Simulation Stations
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KC-135 pilot station
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Uses the Infinity Cube
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Allows pilot to observe and participate
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Provides use of autopilot or “hands-on” flying
KC-135 boom operator station
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Designed specifically for AAR
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Allows boomer to evaluate technologies and
“concepts of employment”
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Need boomers to support the AAR process
Dist A: Public Released
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Precontact Command
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Right Monitor During Rendezvous
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Recent Simulation Events
Tanker’s Semi-Wingspan
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AAR Auto ACAS Simulation
(Summer 2004)
Uncertainties
AAR-Modified
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UAV Position and Pathway Validation Study (Fall 2004)
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Turbulence Evaluations
Post-Refueling
Position
Observation
Position
Contact
Position
Pre-Contact Position
(50 ft behind and 10 ft below the
refueling boom pivoting point)
Dist A: Public Released
GP44153001.ppt
(Winter 2004)
Conventional
GP44153002.ppt
Wingtip Inboard
Vortex Observation
Inboard and
Inboard
Outboard EngineIntermediate
Exhaust
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Future Simulation Events
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Rendezvous Algorithm Development (Spring 2006)
J-UCASs Exit
Refueling Track
Air-to-Air
Refueling
Rendezvous
En Route
ARCP
EAR
Tanker Orbit
275 KIAS
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Storyboard Evaluation (Through 2007 and Beyond)
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Flight Test Support (Summer 2005 – Fall 2007)
Dist A: Public Released
Integrity - Service - Excellence
ARIP
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Capstone Simulation
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Objective
- Demonstrate complete set of AAR system
designs with high fidelity models
- Full concept of operations (CONOPS)
development for multiple UAVs
• Purpose
- Transition AAR four ship CONOPS to
production
• Test Details
- Man in-the loop simulation
- Boom, manned control station, tanker pilot
- Equivalency model
- PGPS effected model
- Data link model
- Turbulence model
Improve Simulation Capability for four ship CONOPS Development
Dist A: Public Released
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Flight Test Objectives
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Mature Precision GPS (PGPS) technology throughout flight test
Reduce technology development risk
Refine simulation models
Gain confidence in system architectures and designs
Enable technology transition to future UAV systems
Dist A: Public Released
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Phase I Open-Loop Data Collection
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Flight Test Objectives
- Qualify Lear Jet for flying around KC-135
- Validate PGPS models and assumptions
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Body masking
Gather real-time GPS and INS data
Gather Electro-Optical sensor data
Validate tanker downwash predictions
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Flight Test Purpose
- Improve PGPS simulation models for
AAR system development
- Augment hybrid system development
• Test Details
- 107th ANG Tanker
- Calspan Lear Jet
Critical to Determine Design Feasibility
Dist A: Public Released
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Precision Positioning System
Accuracy Requirements at Contact
Boom Air-to-Air Refueling Envelope
-15
30
35
40
45
Note: Distances are for zero azimuth angle
Z Distance - ft
-20
-25
One of Several
Positioning System
Requirements
Refueling Envelope
Center
Goal Envelope
Threshold Envelope
-30
X Distance - ft
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Approximation
Envelope
Approximation
Approximation28
TTNT Data Collection
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Flight Test Objectives
- Evaluate real-time performance of
PGPS algorithm with data link
- Evaluate TTNT data link performance
under real-world conditions
- Validate analytical models
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TTNT data link
GPS Receiver
Embedded GPS and INS
Flight Test Purpose
- Characterize PGPS sensors and data
link in real-time
- Critical step for ensuring system integrity
Test Details
- NAVAIR E-2 or T-39
- Calspan Lear Jet
Real World Constraints are Critical to AAR Design
Dist A: Public Released
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PGPS Closed-Loop Station Keeping
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Flight Test Objectives
- Evaluate:
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The performance of updated PGPS models
The interface between guidance navigation system and
flight control system
The PGPS integrity system
The station keeping flight control laws
Update TTNT data link performance
Flight Test Purpose
- Demonstrate PGPS accuracy and integrity
- Validate Lear Jet analytical model
- Verify performance of inner and outer loop
control laws
Test Details
- 107th ANG KC-135
- Calspan Lear Jet 25
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Critical integration of PGPS and Flight Control Laws
Dist A: Public Released
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AAR Graduation Flight Demo
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Flight Test Objectives
- Demonstrate full AAR closed-loop precision
navigation system on a Lear Jet moving
around a KC-135 from Observation->PreContact -> Contact -> Pre-Contact Including
Breakaway
- Validate PGPS performance
- Collect data from candidate EO/IR sensor for
Hybrid system development
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Flight Test Purpose
- Prove AAR system design on Lear Jet
- Provide key metrics for simulation
demonstration
- Ensure AAR technology transition to UAVs
Demonstration Ensures AAR Technology Transition to UAVs
Dist A: Public Released
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Summary
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Air Force Research Laboratory is the World Leader in AAR
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Operationally Relevant
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Meet future refueling requirements
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Synergy between flight test and flight simulation
The AAR Team
is Poised to Meet the
Automated
Refueling Challenge
Dist A: Public Released
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