ERAU

1
ERAUDaytona BeachUAS Projects

• CGAR Conference
• Anchorage, Alaska
• 4 June 2008

2
Acknowledgements

• Xiaogong Lee, Tong Vu, John Zvanya
• FAA Research and Technology Development Branch,
  Airport and Aircraft Safety Team
• Center of Excellence for General Aviation
  Research (CGAR)
• Disclaimer
• The FAA neither endorses nor rejects the findings
  of this research. The presentation of this
  information is made available in the interest of
  invoking technical community comment on the
  results and conclusions of the research.

3
ERAUDB UAS Team

• Chris Griffis
• Chris Reynolds
• Manan Vyas
• Richard Stansbury
• Tim Wilson

4
Introduction

• Aircraft must be certified for operation within
  the National Airspace System
• Few options for Unmanned Aircraft Systems (UAS)
• Certificates of Authorization (CoA)
• Special Airworthiness Certificates
• Operating under restricted airspace

5
Goals

• Survey UAS technology
• Analyze regulatory gaps
• Analyze technology risks

6
Current Research

• Regulatory gap analysis for UAS Detect, Sense,
  and Avoid (DSA)
• Technology survey and regulatory gap analysis for
  UAS Command, Control, and Communication (C3)
• Regulatory gap analysis and risk analysis for UAS
  propulsion systems

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Detect, Sense, and Avoid Regulatory Gap Analysis

• Christopher Reynolds
• Timothy Wilson

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Overview

• Literature review
• Regulatory review
• Technology survey update
• Regulatory gap analysis

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Literature Review

• Collision avoidance
• Role of the AIM
• Traffic separation layers
• Cooperative traffic avoidance technologies
• Non-cooperative technologies
• Applications to UAS

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A Brief History of Collision Avoidance

• Nautical
• 1926 Air Commerce Act
• 1937 Regulations for lighting and visibility
• 1945 Cruising altitudes established
• 1959 See and be seen
• See and Avoid outlined in Part 91

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Traffic Separation Layers
NASA Access 5, Collision Avoidance Functional
Requirements For Step 1, 2006
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Cooperative Traffic Avoidance

• Traffic Alert and Collision Avoidance System
  (TCAS)
• Automatic Dependent Surveillance Broadcast
  (ADS-B)

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TCAS (I)

• Primary cooperative collision avoidance system in
  the national airspace
• TCAS transmits and receives information via
  transponder
• Obtains information regarding relative location
  of other aircraft
• TCAS II provides resolution advisories if
  conflict exists
• RA alerts pilot to conduct specified maneuver

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TCAS (II)

• NASA Access 5, Cooperative Conflict Avoidance,
  Sensor Trade Study Report, 2004

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ADS-B (I)

• Uses satellite-based Global Positioning System to
  determine aircraft location
• Aircraft type, altitude, speed, flight number,
  and maneuvering status are broadcasted
• Aircraft and ground-based stations within
  100-miles can obtain information
• Cockpit Display of Traffic Information increases
  situational awareness

16
ADS-B (II)
NASA Access 5, Cooperative Conflict Avoidance,
Sensor Trade Study Report, 2004
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Non-Cooperative Technologies

• Active technologies
• RADAR, including SAR
• LASER
• Passive technologies
• Electro-optical
• Infrared
• Acoustic

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Regulatory Review

• Part 91
• AIM
• Other materials
• Orders
• ACs
• Pilot Handbook and Manuals

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Collaborative Layering
Preventive Procedures Rules, guidelines, and advisories established and adhered to by cooperative pilots in an effort to prevent collisions through detection and avoidance.
Subsidiary Systems Two-way external systems, such as Air Traffic Control and other aircraft operators that forward useful information and assistance to the pilot in an effort to increase situational awareness and prevent collisions.
Machine Detection The incorporation of machine-based systems that enhance the operators situational awareness in an effort to prevent collisions.
Human Execution Human execution incorporates the operator as the sole manipulator of the aircraft controls. Human responses are based on both training and instinct in an effort to avoid hazardous situations, including collisions, by maneuvering the aircraft.
Human Cognition The decision-making and reasoning ability of the human operator to choose the best course of action. This includes collision avoidance, and emergency situations.
Human Detection The ability of the human operator to harness their five senses in an effort to detect aircraft. This includes visual detection, and noise detection.
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FAR/AIM Analysis
H-High Application HD Human Detection MD Machine Detection
M-Moderate Application HC Human Cognition SD Subsidiary System
L-Low Application HE Human Execution PP Preventive Procedures
CA Clearly Applies MA May Apply Through Interpretation R May Apply with Revision
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FAR/AIM Details
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Highly Applicable Sections

• FAR
• Sec. 91.111 Operating near other aircraft
• Sec. 91.113 Right-of-way rules Except water
  operations
• Sec. 91.115 Right-of-way rules Water operations
• AIM
• 4-4-14 Visual Separation
• 4-4-15 Use of Visual Clearing Procedures
• 5-5-8 See and Avoid
• 8-1-6 Vision in Flight
• 8-1-8 Judgment Aspects of Collision Avoidance

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Technology Survey Update

• Tech survey update
• Material from RTCA/SC-203
• Recent publications
• Further literature review

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Gap Analysis

• Itemize technologies not covered by contemporary
  regulations

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Questions
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UAS Technologies for Command, Control, and
Communications

• Richard Stansbury,
• Manan Vyas, and Timothy Wilson

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Overview

• Introduction
• Technology survey
• Systems level model
• RF line-of-sight
• Beyond RF line-of-sight
• Security issues
• Existing protocols and regulations
• Future work

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Approach

• Perform a technology survey of existing C3
  technologies and issues for UAS
• Articulate technology issues
• Perform a regulatory gap analysis

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Systems Level Model
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UAS Classes

• Low-endurance UAS
• Manta B, Silver Fox, Raven, Dragon Eye, etc.
• Medium-endurance UAS
• ScanEagle, Meridian, Global Ranger, Shadow, etc.
• High-endurance UAS
• Predator, Mariner, Global Hawk, etc.

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RF Line-of-Sight Data Links
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RF Line-of-Sight Autonomy

• UA remotely piloted from ground station vs.
  flying predefined waypoints via autopilot
• Low endurance (LE) UAS
• Remotely piloted for takeoffs and landings
• Waypoint navigation or remotely piloted during
  mission
• High endurance (HE) UAS
• Entire mission via waypoint navigation

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RF Line-of-Sight Other

• Lost link procedure
• Return to a pre-defined location (e.g. home base)
  or last location in which link was active
• Autonomously land or loiter until link
  re-established, etc.
• ATC Coordination
• For LOS-only UAS, handled from a VHF radio at
  ground-station to ATC

34
RF BLOS Data Links
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RF BLOS SATCOM

• Often undisclosed for surveyed military UAS
• Low Earth Orbit Satellite
• More satellites to cover same footprint.
• Lower latency
• Higher maintenance costs
• e.g. Iridium, Globalstar, etc.
• Geosynchronous Earth Orbit Satellite
• Fewer satellites
• Higher latency
• Less lost link due to satellite handoff
• Higher launch costs
• e.g. Inmarsat

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RF BLOS Autonomy

• Higher latency often results in less pilot
  control and more required autonomy
• Medium endurance
• Pilot intervention or remote control while still
  LOS
• e.g. remote controlled takeoff and landing
• Autopilot for majority of flight path
• High endurance
• Taxi, takeoff, flight operations, and landing all
  done autonomously
• Aircraft autonomy is acknowledged by FAA, but
  remains a concern
• Detect, Sense, and Avoid must also be resolved

37
RF BLOS ATC

• Approaches
• UAS as a Relay VHF transceiver on UAS
• Ground-based network phone-based
• Larger issue comes when UAS may operate across
  multiple ATC cells
• Current UAS ascends rapidly to FL 600
• No protocols for UAS across various cells
• Who has the responsibility for handoffs?

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RF BLOS Lost Link Procedure

• Similar to LOS procedure
• Return to a known point and do something
• Less feasible to return home
• Pre-planned landing sights or loitering airspace
• For CoA, lost-link procedure must exists
• Currently
• High coordination with FAA prior to mission
• Contingency landing / loitering sights
• Ability to terminate flight

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Data Link Security Issues

• Data links susceptible to spoofing, hi-jacking
  and jamming
• Safety critical because pilot is not in
  immediate control of the aircraft
• Security features must be built into the system
• UA to acknowledge or echo all commands
• Military uses CDL and Link 16 data links with
  built-in validation

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Existing Protocols and Regulations

• Communication protocols
• STANAG 4586
• JAUS
• Existing regulations
• ICAO Annex 10
• FAA Interim Guidelines

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STANAG 4586
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Functional Architecture Overview

• Core UCS
• Ground control system
• No implementation specified
• VSM
• Vehicle Specific Module
• CCISM
• C4I Interface Specific Module
• HCISM
• HCI Specific Module

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Data link interface

• Discusses interface between the ground control
  (UCS) and the aircraft
• VSM provided by manufacturer translates UAV data
  into compatible form.
• Avoids modification to existing air vehicle
  software (legacy support)
• Identifies a set of common messages
• Aircraft status, data, control
• Payload data and control (not relevant to FAA
  project)

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STANAG 4586 Distilment
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JAUS

• Joint Architecture for Unmanned Systems
• Originally, under DoD and managed by JAUS Working
  Group
• Currently, under SAE AS-4 Committee
• Define interoperability standards for
  heterogeneous unmanned systems
• Support Documents
• Volume 1 Domain model
• Volume 2 Reference Architectures
• Part 1 Architecture Framework
• Part 2 Message Definition
• Part 3 Message Set

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JAUS Reference Architecture

• Systems and components are abstracted much
  further than STANAG 4586 to generalize for all
  unmanned systems
• Technical Constraints
• Imposed to ensure that the architecture is
  applicable to all Unmanned Systems
• Platform Independence
• Mission Isolation
• Computer Hardware Independence
• Technology Independence

47
ICAO Annex 10

• ICAO introduces new standards and practices for
  safety of international aviation
• Annex 10 Aeronautical Telecommunications
• Volume III Communication Systems
• System level requirements for
• Aeronautical telecommunications
• Mobile satellite services
• VHF air-to-ground digital data links
• HF links, etc.
• Functionality, requirements, recommendations,
  message protocols

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FAA Interim Guidelines

• Document FAA Interim Operational Approval
  Guidance 08-01
• Initial guidance toward those seeking CoAs or
  Special Airworthiness Certificate for UAS
• Relevant Requirements
• Observer required at all times
• Ground or Chase Aircraft
• Flight termination system in place
• Lost-link procedures must be defined

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FAA Interim Guidelines (2)

• Relevant requirements
• Pilot-in-command designated at all times during
  operations
• ATC communication link required at all times
• If operating under IFR flight plan, ATC link must
  be handled by aircraft as a relay
• Must be equipped with a Mode C transponder
• Mode S preferred

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Conclusions and Future Work

• Identified existing technology and several issues
  relevant to UAS C3.
• Must investigate the FARs and enumerate existing
  issues
• Perform regulatory gap analysis on the FARs
• Determine where the existing regulations fail to
  meet the needs of the current technology that we
  wish to certify

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Continuing Work

• Regulatory Gap Analysis
• Examine FAA regulations 14 CFR Part 21, 23, 27.
  29, 91, etc. and AIM
• Do a comparative study of STANAG 4586, ICAO, FAA
  regulations and technology survey findings
• Outcome Gaps identified between FAA regulations
  and current UAS C3 technology

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Questions
53
UAS Propulsion SystemsGap Analysis / Risk
Analysis

• Christopher Griffis
• Timothy Wilson

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UAS Propulsion System Research Overview

• Technology Survey Review
• UAS Propulsion Systems
• Regulatory Gap Analysis
• Risk Analysis
• Recommendations

55
Technology Survey Review

• The Ten Propulsion Technologies

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The Ten Propulsion Technologies (I)

• Reciprocating piston engines (RP)
• Wankel rotary engines (RO)
• Propeller driven systems (PR)
• Gas turbine propulsion systems (GT)
• Rocket powered means of propulsion (RK)

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The Ten Propulsion Technologies (II)

• Systems with motion derived from electric motor
  power (EM)
• Battery-based propulsion systems (BB)
• Fuel cell powered propulsion systems (FC)
• Solar/photovoltaic powered systems (PH)
• Systems utilizing ultracapacitor based means of
  energy storage (UC)

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Conceptual Decomposition of UAS Propulsion Systems

• An Energy Source (ES), representing the physics
  and mechanisms responsible for liberating stored
  or accumulated energy
• An Energy Transformer (ET), that draws from the
  ES to produce the input power (e.g. thermodynamic
  or electromagnetic) operating the powerplant
• A Powerplant (PP), running off of the energy
  transformer, driving the propulsions effecter
• A Propulsion Effecter (PE) that gives the effect
  of motion, and
• A Control Effecter (CE) that somehow controls
  this process

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Regulatory Gap Analysis

• Objectives
• Process
• Speadsheet
• Fundamental gap
• Open-set gap

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Gap Analysis Objectives

• Identify the categories of regulatory guidelines
  that will be looked at
• Perform proper scoping of the project to make the
  findings manageable and usable.
• Determine how to manage the complexity of all the
  dimensions of this gap analysis
• Create a matrix that concisely and compactly
  stores and communicates this information
• Perform a global assessment of gaps that exist
  with regard to the current state of regulation
• Perform an individual assessment of each FAR as
  it relates to UAS propulsion, explaining its
  assessment with regard to the applicability
  criteria.
• Create a document that encapsulates the essential
  information in summarizing and communicating
  these gaps

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Gap Analysis Mechanisms (I)

• Gap analysis spreadsheet as a concise way to
  present a broad matrix of information
• Looks at multiple perspectives as they relate to
  each regulation
• Dimensions of Applicability
• Propulsion system categories from Tech Survey
• Relation to the Conceptual Model
• Color-coded grouping for layering of information

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Gap Analysis Mechanisms (II)
63
Spreadsheet Regulations vs. Technology and
Conceptual
64
Gap Analysis EM Systems
RP Issues that are covered by existing
regulation (very large region)
RP Issues not covered by existing regulation
(very small region)
GT Issues not covered by existing regulation
(very small region)
Regulatory Gaps!!! (Areas not covered, even by
interpretation of existing FARs)
EM Issues Covered by interpretation of FARs for
existing RP/GT Regulation
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The Fundamental Gap

• Current regulations
• Implicit assumption that propulsion for manned
  aircraft only comes from two types of
  powerplant/energy transformers gas turbine
  engines and reciprocating piston engines
• Almost specifically do not regulate the concept
  of a pure electrically driven motor as the
  powerplant for an aircraft system.
• UAS that use EM based propulsion arent covered
• Also means that predicate technologies in the
  conceptual chain aren't covered (ES and ET like
  fuel cell, long endurance battery,
  ultracapacitors, etc)
• RESULT
• Using regulatory provisions for things relating
  to heat and thermodynamically based means of
  propulsion to guide safety aspects of EM based
  systems now become a matter of interpretation (as
  it stands)
• In some cases for EM, there isn't even a basis
  for interpretation in existing guidelines
• RECOMMENDATION
• Embrace this concept and develop system
  size-invariant safety guidelines (regulations)
  addressing the needs of pure EM based systems

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The Open-Set Gap

• Current regulations
• Very specific about turbine and reciprocating
  engines
• Have a scattered collection of coverage
  regulations that say, if this cant be done, at
  least do this. (tantamount to ELOS guidelines)
• Concept of for everything else may now become
  important
• New UAS technology can fall into the category of
  everything else, as demonstrated by EM based
  systems
• RESULT
• Future paradigm shifts in approaches to aviation
  will require high overhead response
• RECOMMENDATION
• Encapsulate the general parameters of safe
  aircraft operation and design in a way that
  covers the everything else category

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Risk Analysis

• Objectives
• Analysis Artifacts
• Risk Assessment by Propulsion Technology
• Risk Assessment by Conceptual Component

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Risk Analysis Objectives

• Based on FAA SRM Order 8040.4
• Implement safety risk management by performing
  risk assessment and analysis and using the
  results to make decisions
• Plan the risk assessment and analysis must be
  predetermined, documented in a plan which must
  include the criteria for acceptable risk
• Hazard identification the hazard analyses and
  assessments required in the plan must identify
  the safety risks associated with the system or
  operations under evaluation
• Analysis the risks must be characterized in
  terms of severity of consequence and likelihood
  of occurrence
• Risk Assessment the risk assessment of the
  hazards examined must be compared to the
  acceptability criteria specified in the plan and
  the results provided in a manner and method
  easily adapted for decision-making
• Decision the risk management decision must
  include the safety risk assessment and the risk
  assessments may be used to compare and contrast
  options

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Risk Analysis Artifacts (I) Preliminary Hazard
List
70
Risk Analysis Artifacts (II)
Severity

• Catastrophic
• Critical
• Marginal
• Negligible

Likelihood

• Frequent
• Probable
• Occasional
• Remote

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Risk Assessment by Propulsion Technology

• Thermodynamic types of propulsions tend to have
  issues surrounding the mechanics of operation
• Noise, vibration, high temperature, and similar
  mechanical failures
• Mostly covered in current regulations
• Electric types of propulsion tend to use newer
  technologies
• Risks related to intricacies of these new
  technologies

72
Risk Assessment by Conceptual Component

• Small UAS almost exclusively implement propellers
  as the propulsion effecters
• Risks related to use of propeller technology
• Risks associated with small EM based UAS
  propulsion technology
• Risk exposure comes less from the electric motor
  and more from the powering technology
• Fuel cells, batteries, solar power,
  ultracapacitors

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Recommendation

• Dealing with the Fundamental Gap
• Dealing with the Open-Set Gap

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Dealing with the Fundamental Gap

• Address the needs of EM systems
• Use a generalized conceptual approach instead of
  a technology specific approach
• Regulation of general safety parameters for a
  conceptual powerplant implemented as an electric
  motor
• Safety parameters of an Energy Transformers
  (such as fuel cell or battery) output into an
  electric motor driven UAS propulsion system,
• Safety parameters addressing concerns of any
  unspecified Energy Transformer (ET) unit output
  leading into any unspecified Powerplant (such as
  an electric motor).

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Dealing with the Open-Set Gap

• Extending the conceptual framework
• Conceptual Components, Interfaces, and
  Interactions
• Regulations in this manner are better suited for
  standard application to new technologies, as
  opposed to the need for interpretation
• Further research is needed to investigate this
  route

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UAS Propulsion System Research Overview

• Technology Survey Review
• UAS Propulsion System Regulatory Gap Analysis
• UAS Propulsion System Risk Analysis
• Recommendations

77
Questions